Dr. Jeff Masters' WunderBlog

Western Caribbean disturbance aims to soak the Yucatan

By: JeffMasters, 8:53 PM GMT en Octubre 31, 2006

Unsettled weather continues in the Western Caribbean in association with a tropical disturbance (93L) that has developed a weak surface circulation this afternoon. The circulation center of 93L was at 20N 83W at 3pm EST this afternoon, moving west-northwest at about 15 mph. The disturbance is under 20 knots of wind shear. This shear is expected to increase to 30 knots on Wednesday, so I am not expecting 93L to develop into a tropical depression. The disturbance should bring heavy rains to Mexico's Yucatan Peninsula Wednesday afternoon through Thursday. At this time, it does not appear that 93L will affect South Florida, although moisture from the surface trough of low pressure 93L is embedded in will increase the chance of rain by Wednesday night. QuikSCAT satellite-measured winds were in the 20-30 mph range southwest of Jamaica at 6:03am EST this morning. 93L will pass over buoy 42056 at 20N 85W tonight. Winds at the buoy this afternoon have been less than 15 mph.


Figure 2. Preliminary models tracks for the Western Caribbean disturbance.

In the Pacific, Typhoon Cimaron has made an abrupt course change, and is now on track to strike China near Hong Kong on Friday as a tropical storm.

Jeff Masters

Updated: 11:07 PM GMT en Octubre 31, 2006

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Damage in the Philippines from Typhoon Cimaron not as severe as expected; quiet in the Atlantic

By: JeffMasters, 2:31 PM GMT en Octubre 31, 2006

Typhoon Cimaron is slowly intensifying over the South China Sea as it heads towards an expected landfall Friday in China. Cimaron made landfall on the northern Philippine island of Luzon Sunday as a Category 5 storm with maximum sustained winds of 160-180 mph. Cimaron killed at least 15, left 2500 homeless, and destroyed about 8% of the island's rice and corn crop. However, disaster officials called the destruction wrought by Cimaron as "minimal" compared to the destruction of devastating Typhoon Xangsane, which hit Luzon on September 27 as a Category 4 storm. Xangsane killed 218 in the Philippines, did over $100 million in damage, and left tens of thousands homeless. Xangsane went on to deliver a serious blow to Vietnam as a Category 2 typhoon, killing 70. Cimaron is expected to weaken due to wind shear and entrainment of dry air off the coast of China as it approaches land later this week.


Figure 1. Super Typhoon Cimaron at 0540 GMT Oct 29 2006, in an image taken by the NASA Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This instrument is able to see details as small as 6km across, and was the only microwave sensor that saw these incredibly tightly packed concentric eyewalls separated by only a few kilometers. Cimaron had one of the most remarkable intensification spurts on record--it went from a minimal tropical storm with 40 mph winds to a Category 5 storm with 160-180 mph winds in just 48 hours. The pressure dropped an estimated 118 mb in that time period! Like Hurricane Wilma of 2005, Cimaron had a very tight inner core with a small eye, which is typical of storms that perform freakish feats of rapid intensification.

The Atlantic
Unsettled weather continues in the Western Caribbean, and we will have to keep an eye on this region for tropical development. QuikSCAT satellite-measured winds were in the 20-30 mph range southwest of Jamaica at 6:03am EST this morning, but there was no evidence of a surface circulation. Wind shear is a low 10 knots over the region, and is expected to remain low over the next several days. No computer models are calling for tropical storm formation in the Atlantic this week, and I am not expecting anything to form in the Atlantic the rest of the year.


Figure 2. Preliminary models tracks for the Western Caribbean disturbance.

Hawaii
The weak tropical disturbance near 10N 175W, about 1500 miles southwest of Hawaii, has dissipated and is no longer a threat.

Jeff Masters

Updated: 7:32 PM GMT en Octubre 31, 2006

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Philippines count the dead after Typhoon Cimaron

By: JeffMasters, 3:07 PM GMT en Octubre 30, 2006

Super Typhoon Cimaron made landfall on the northern Philippine island of Luzon this weekend as a Category 5 storm with maximum sustained winds of at least 160 mph. Cimaron could have been even stronger--NOAA's satellite team estimated Cimaron had 180 mph sustained winds with a pressure of 879 mb, but the University of Wisconsin CIMSS group put Cimaron's peak intensity at 160 mph, with a central pressure of 903 mb. Cimaron had one of the most remarkable intensification spurts on record--it went from a minimal tropical storm with 40 mph winds to a Category 5 storm with 160-180 mph winds in just 48 hours. The pressure dropped an estimated 118 mb in that time period! Like Hurricane Wilma of 2005, Cimaron had a very tight inner core with a small eye, which is typical of storms that perform freakish feats of rapid intensification. Cimaron was the strongest typhoon to hit the Philippines in eight years.


Figure 1.A zoomed-in shot of Cimaron's eye taken by NASA's AQUA satellite shortly before the storm made landfall in the Philippines.

Damage reports are just beginning to come in from the Philippines, and early reports put the death toll at 12 with over 20 injured. Most of the deaths have come from flooding and falling trees. Northern Luzon Island is very mountainous and heavily logged, so flash flooding presents a serious danger. Cimaron moved quickly enough that only about eight inches of rain fell across the island (Figure 2), so I am hopeful that the death toll will not increase much further. The coast is not heavily populated where Cimaron came ashore, so significant death or damage there is not expected. About 5,000 people were evacuated from low-lying areas before Cimaron came ashore.


Figure 2.Rainfall estimates from NOAA for Cimaron.

Cimaron follows on the heels of devastating Typhoon Xangsane which hit Luzon on September 27 as a Category 4 storm. Xangsane killed 218 in the Philippines, did over $100 million in damage, and left thousands homeless. All 43 million residents of Luzon lost power from that typhoon. Xangsane went on to deliver a serious blow to Vietnam as a Category 2 typhoon, killing 70. Cimaron is expected to hit Vietnam Thursday night in the same region Xangsane did. However, Cimaron is expected to be much weaker at this second landfall--perhaps just a tropical storm.


Figure 3.Super Typhoon Cimaron a few hours before landfall in the Philippines. Cimaron may have had sustained winds as high as 180 mph at landfall! Image credit: NOAA.

The Atlantic
The tropical wave (93L) moving through the Caribbean south of Jamaica has grown very disorganized, and development of this system is not expected. None of the computer models are forecasting tropical development in the Atlantic the remainder of this week, but unsettled weather is expected to remain in the western Caribbean.

Hawaii
A weak tropical disturbance near 10N 175W, about 1300 miles southwest of Hawaii, has the potential for some slow development this week as it moves towards Hawaii. Several of the computers models are predicting that this could develop into a weak tropical storm and affect Hawaii by Friday or Saturday. The disturbance is under about 15 knots of wind shear, and had top winds of about 25 mph in last night's QuikSCAT satellite pass.

Jeff Masters

Updated: 3:09 PM GMT en Octubre 30, 2006

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Caribbean disturbance grows disorganized; Super Typhoon Cimaron batters the Philippines

By: JeffMasters, 1:23 AM GMT en Octubre 30, 2006

A tropical wave (93L) moving through the Caribbean south of Jamaica has grown less organized today, despite having only 10 knots of wind shear over it. Wind shear is forecast to remain below 15 knots over the Caribbean over the next two days, which may allow some slow development of the system. However, none of the models are developing the system, and I am not expecting it to become a tropical depression. 93L will bring heavy rains and flooding to Jamaica and Cuba over the next day. These rains should spread into the Bahamas on Monday.


Figure 1.Preliminary model tracks for tropical disturbance 93L.

Philippines hammered by Super Typhoon Cimaron
Super Typhoon Cimaron made landfall on the northern Philippine island of Luzon this weekend as a Category 5 storm with winds of at least 160 mph. There is no word yet on damage from the storm, and I'll have much more on this extraordinary typhoon in my blog Monday morning.


Figure 2.Super Typhoon Cimaron a few hours before landfall in the Philippines. Cimaron may have had sustained winds as high as 180-195 mph at landfall! Image credit: NOAA.

Jeff Masters

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Lesser Antilles disturbance; big money for hurricane research?

By: JeffMasters, 1:53 PM GMT en Octubre 28, 2006

A tropical wave (93L) moving through the Lesser Antilles Islands has not gotten better organized since yesterday. Winds from this morning's QuikSCAT satellite pass were in the 20-30 mph range. Wind shear is about 10 knots over the disturbance, and is forecast to remain below 15 knots over the eastern Caribbean over the next two days. This may allow some slow development of the system. The models are indicating that if the disturbance crosses Cuba and enters the Bahamas, it may have a chance to develop early next week as it recurves northeastward out to sea. The disturbance may bring heavy rains to the Dominican Republic, Haiti, and Cuba Sunday through Monday. I don't expect this system will become a tropical depression, but it is something we need to keep an eye on. This system is not a threat to the East Coast of Florida. My next update on this system will be Sunday evening.


Figure 1.Preliminary model tracks for tropical disurbance 93L.

The National Hurricane Research Initiative (NHRI)
There's big money proposed to fund new hurricane research. The National Science Board, in a report issued September 29, 2006, calls for an increase of $300 million per year in hurricane research funding. That's a whopping increase in funding, when one considers that the average annual spending on hurricane research has been only $20 million the past six years. So, what is the National Science Board, and this a reasonable proposal?

National Science Board
The 24 members of the National Science Board are appointed by the President of the United States, and make budget recommendations for the National Science Foundation (NSF). The NSF has an annual budget of about $5.6 billion (fiscal year 2006), and funds approximately 20 percent of all federally supported basic research conducted by America's colleges and universities. So, this is a very serious proposal by a group which has real power to influence the Federal budget.

Major recommendations of the report
The primary recommendation of the report is the formation of a National Hurricane Research Initiative (NHRI), which will "provide urgently needed hurricane science and engineering research and education". As justification for this effort, the report notes that that hurricane damage is increasing, with annual total losses (in constant 2006 dollars) averaging $1.3 billion from 1949-1989, $10.1 billion from 1990-1995, and $35.8 billion per year during the last 5 years. $168 billion in losses occurred in 2004 and 2005 alone. Over 50% of the population lives within 50 miles of the coast, and the value of infrastructure in the Gulf and Atlantic coast areas is over $3 trillion, with trillions more in investment likely in the next few decades as the U.S. population continues to expand. This incredible investment will be increasingly affected by hurricanes, and scientists "know relatively little about the most important aspects of hurricanes including their internal dynamics and interactions with the larger-scale atmosphere and ocean; methods for quantifying and conveying uncertainty and mitigating hurricane impacts; associated short and long term consequences on the natural and built environment; and the manner in which society responds before, during, and after landfall." The study notes that "billions of tax dollars have been provided for rescue, recovery, and rebuilding after hurricanes strike", but more money needs to be spent minimizing losses from hurricanes before they strike. In fact, had the NHRI been funded two years ago, much of the devastation wrought by Katrina could have been avoided. The program funds engineering studies to evaluate the structural integrity of the entire coastal infrastucture including levees, seawalls, drainage systems, bridges, water/sewage, power, and communications. The flaws in the New Orleans levees that led to over 80% of the city's flooding could have been found and fixed before Katrina hit had such a program been funded earlier.

The report has many excellent suggestions on how to make a coordinated research effort that will pay big dividends over the coming years by reducing our vulnerability to hurricanes. For example, the report seeks funding for research on improving evacuation planning, so that we can avoid a repeat of the debacle that occurred during the evacuation of Houston for Hurricane Rita. Over 100 people died in the evacuation effort. Research on improved disaster communications technologies is proposed, so that we avoid the situation that arose in Katrina where FEMA had no idea what was going on at the Convention Center.

My only gripe about the report is the inclusion of funding for research on human modification of hurricanes to reduce their intensity or alter their movement. I don't believe we should be messing with these great storms until we understand better how they work. In addition, given the sheer size and incredible energy that storms have, modification efforts will likely be an ineffectual waste of time and money. Finally, I don't think the legal system in this country will allow hurricane modification to occur without a lot of lawsuits being filed. I don't know too many hurricane scientists who are in favor of hurricane modification research, and suspect it is being funded for political reasons.

Is $300 million a reasonable request?
To do a thorough job of reducing our vulnerability to hurricanes, $300 million per year is a reasonable amount to spend. However, the U.S. faces a number of threats that also require large outlays of dollars, such as bioterrorism and earthquakes. The framers of the report realize that getting a $300 million per year project funded in a time of "increasingly small non-defense discretionary budgets" is difficult. To put this number in perspective, the annual amount spent in the U.S. on meteorology operations and supporting research is $3 billion. About $1 billion/year of this goes to run the National Weather Service, with weather satellites consuming another big chunk of the costs. But consider the amount being spent on defending the country against bioterrorism. The federal budget for bioterrorism emergency preparedness has ranged between $3 and $6 billion per year since 2002. The request for FY 2007 is $4.3 billion. That's over 200 times what we spend on hurricane research, and over ten times the $300 million being proposed. While others will disagree, I believe that the threat of catastrophe from hurricane strikes on the U.S. is much higher than that from bioterrorism. If we need to find funding for the NHRI, the bioterrorism budget can suffer a 7% cut. Another hurricane as strong as Hurricane Katrina is certain to hit a major populated area in the future, while a bioterrorism attack is not certain, and hopefully not even probable. There are wiser ways to spend our disaster preparedness dollars than what we are doing.

National Hurricane Research Initiative Act of 2006
Sen. Mel Martinez, R-Fla., introduced the National Hurricane Research Initiative Act of 2006, a bi-partisan bill that adopts the recommendations of the report. The proposed legislation puts NOAA and the National Science Foundation in charge of coordinating the research initiative. Not surprisingly, the bill is being co-sponsored by Florida's other Senator, Sen. Nelson (D-FL), and Louisiana's two Senators, Sen. Vitter (R-LA), and Sen. Landrieu (D-LA). Apparently, the Senators from the states hard hit by the hurricanes of 2004 and 2005 felt that $300 million per year wasn't enough, and ask for $435 million in funding per year through 2017.

Some historical perspective
In 1898, the United States fought the Spanish-American War. With the U.S. Navy heavily committed to operations in the Caribbean during the height of hurricane season, Willis L. Moore, Chief of the Weather Bureau, saw the need set up an improved hurricane warning system. Moore took a long view through the history of naval warfare and discovered that more armadas had been destroyed by weather than by the enemy. He placed his findings before President McKinley, and proposed that the U.S. spend money to establish a new hurricane warning service, despite the fact that budgets were tight in a time of war. McKinley responded to Moore: "I am more afraid of a West Indian hurricane than the entire Spanish Navy. Get this [hurricane warning] service inaugurated at the earliest possible moment!"

The Spanish are no longer our enemies, but the threat of hurricanes remains and will worsen if we do nothing. I hope today's politicians will emulate President McKinley, and take the long view of history. In the words of the report's conclusion:

Can we as a Nation continue to remain vulnerable to hurricanes that are an inevitable part of our future, that have demonstrated the capacity to inflict catastrophic damage to our economy, and that kill hundreds of our citizens? The hurricane warning for our Nation has been issued and we must act vigorously and without delay.

I urge you to write your Senators to support S, 4005, the National Hurricane Research Initiative Act of 2006. The public is also invited to email their comments on the report to the National Science Foundation at NSBHSE@nsf.gov before Sunday, October 29, 2006. Those of you in Louisiana and Florida probably do not need to write your Senators--they are definitely on board on this one!

Jeff Masters

Permalink

Lesser Antilles tropical wave; big money for hurricane research?

By: JeffMasters, 9:47 PM GMT en Octubre 27, 2006

A tropical wave (93L) moving through the Lesser Antilles Islands has gotten better organized today. Wind shear has dropped to 5 knots over the disturbance, and some modest thunderstorm activity has built up. Wind shear is forecast to remain below 15 knots over the eastern Caribbean over the next two days, which may allow some slow development of the system. The track of the disturbance should take it near the Dominican Republic on Sunday, and the island of Hispaniola will probably get heavy rains from this system on Sunday and Monday. I don't expect this system will become a tropical depression, but it is something we need to keep an eye on. This system is not a threat to the East Coast of Florida.


Figure 1.Preliminary model tracks for tropical disurbance 93L.

World Series tonight a GO
Tonight's World Series game in St. Louis between the Tigers and the Cardinals should not suffer any rain delays. Game time temperature should be about 45 degrees, with a strong 15 mph wind blowing out to center field.

The National Hurricane Research Initiative (NHRI)
There's big money proposed to fund new hurricane research. The National Science Board, in a report issued September 29, 2006, calls for an increase of $300 million per year in hurricane research funding. That's a whopping increase in funding, when one considers that the average annual spending on hurricane research has been only $20 million the past six years. So, what is the National Science Board, and this a reasonable proposal?

National Science Board
The 24 members of the National Science Board are appointed by the President of the United States, and make budget recommendations for the National Science Foundation (NSF). The NSF has an annual budget of about $5.6 billion (fiscal year 2006), and funds approximately 20 percent of all federally supported basic research conducted by America's colleges and universities. So, this is a very serious proposal by a group which has real power to influence the Federal budget.

Major recommendations of the report
The primary recommendation of the report is the formation of a National Hurricane Research Initiative (NHRI), which will "provide urgently needed hurricane science and engineering research and education". As justification for this effort, the report notes that that hurricane damage is increasing, with annual total losses (in constant 2006 dollars) averaging $1.3 billion from 1949-1989, $10.1 billion from 1990-1995, and $35.8 billion per year during the last 5 years. $168 billion in losses occurred in 2004 and 2005 alone. Over 50% of the population lives within 50 miles of the coast, and the value of infrastructure in the Gulf and Atlantic coast areas is over $3 trillion, with trillions more in investment likely in the next few decades as the U.S. population continues to expand. This incredible investment will be increasingly affected by hurricanes, and scientists "know relatively little about the most important aspects of hurricanes including their internal dynamics and interactions with the larger-scale atmosphere and ocean; methods for quantifying and conveying uncertainty and mitigating hurricane impacts; associated short and long term consequences on the natural and built environment; and the manner in which society responds before, during, and after landfall." The study notes that "billions of tax dollars have been provided for rescue, recovery, and rebuilding after hurricanes strike", but more money needs to be spent minimizing losses from hurricanes before they strike. In fact, had the NHRI been funded two years ago, much of the devastation wrought by Katrina could have been avoided. The program funds engineering studies to evaluate the structural integrity of the entire coastal infrastucture including levees, seawalls, drainage systems, bridges, water/sewage, power, and communications. The flaws in the New Orleans levees that led to over 80% of the city's flooding could have been found and fixed before Katrina hit had such a program been funded earlier.

The report has many excellent suggestions on how to make a coordinated research effort that will pay big dividends over the coming years by reducing our vulnerability to hurricanes. For example, the report seeks funding for research on improving evacuation planning, so that we can avoid a repeat of the debacle that occurred during the evacuation of Houston for Hurricane Rita. Over 100 people died in the evacuation effort. Research on improved disaster communications technologies is proposed, so that we avoid the situation that arose in Katrina where FEMA had no idea what was going on at the Convention Center.

My only gripe about the report is the inclusion of funding for research on human modification of hurricanes to reduce their intensity or alter their movement. I don't believe we should be messing with these great storms until we understand better how they work. In addition, given the sheer size and incredible energy that storms have, modification efforts will likely be an ineffectual waste of time and money. Finally, I don't think the legal system in this country will allow hurricane modification to occur without a lot of lawsuits being filed. I don't know too many hurricane scientists who are in favor of hurricane modification research, and suspect it is being funded for political reasons.

Is $300 million a reasonable request?
To do a thorough job of reducing our vulnerability to hurricanes, $300 million per year is a reasonable amount to spend. However, the U.S. faces a number of threats that also require large outlays of dollars, such as bioterrorism and earthquakes. The framers of the report realize that getting a $300 million per year project funded in a time of "increasingly small non-defense discretionary budgets" is difficult. To put this number in perspective, the annual amount spent in the U.S. on meteorology operations and supporting research is $3 billion. About $1 billion/year of this goes to run the National Weather Service, with weather satellites consuming another big chunk of the costs. But consider the amount being spent on defending the country against bioterrorism. The federal budget for bioterrorism emergency preparedness has ranged between $3 and $6 billion per year since 2002. The request for FY 2007 is $4.3 billion. That's over 200 times what we spend on hurricane research, and over ten times the $300 million being proposed. While others will disagree, I believe that the threat of catastrophe from hurricane strikes on the U.S. is much higher than that from bioterrorism. If we need to find funding for the NHRI, the bioterrorism budget can suffer a 7% cut. Another hurricane as strong as Hurricane Katrina is certain to hit a major populated area in the future, while a bioterrorism attack is not certain, and hopefully not even probable. There are wiser ways to spend our disaster preparedness dollars than what we are doing.

National Hurricane Research Initiative Act of 2006
Sen. Mel Martinez, R-Fla., introduced the National Hurricane Research Initiative Act of 2006, a bi-partisan bill that adopts the recommendations of the report. The proposed legislation puts NOAA and the National Science Foundation in charge of coordinating the research initiative. Not surprisingly, the bill is being co-sponsored by Florida's other Senator, Sen. Nelson (D-FL), and Louisiana's two Senators, Sen. Vitter (R-LA), and Sen. Landrieu (D-LA). Apparently, the Senators from the states hard hit by the hurricanes of 2004 and 2005 felt that $300 million per year wasn't enough, and ask for $435 million in funding per year through 2017.

Some historical perspective
In 1898, the United States fought the Spanish-American War. With the U.S. Navy heavily committed to operations in the Caribbean during the height of hurricane season, Willis L. Moore, Chief of the Weather Bureau, saw the need set up an improved hurricane warning system. Moore took a long view through the history of naval warfare and discovered that more armadas had been destroyed by weather than by the enemy. He placed his findings before President McKinley, and proposed that the U.S. spend money to establish a new hurricane warning service, despite the fact that budgets were tight in a time of war. McKinley responded to Moore: "I am more afraid of a West Indian hurricane than the entire Spanish Navy. Get this [hurricane warning] service inaugurated at the earliest possible moment!"

The Spanish are no longer our enemies, but the threat of hurricanes remains and will worsen if we do nothing. I hope today's politicians will emulate President McKinley, and take the long view of history. In the words of the report's conclusion:

Can we as a Nation continue to remain vulnerable to hurricanes that are an inevitable part of our future, that have demonstrated the capacity to inflict catastrophic damage to our economy, and that kill hundreds of our citizens? The hurricane warning for our Nation has been issued and we must act vigorously and without delay.

I urge you to write your Senators to support S, 4005, the National Hurricane Research Initiative Act of 2006. The public is also invited to email their comments on the report to the National Science Foundation at NSBHSE@nsf.gov before Sunday, October 29, 2006. Those of you in Louisiana and Florida probably do not need to write your Senators--they are definitely on board on this one!

I'll likely update just the first few sentences of this blog this weekend. I'll post a new blog on Monday.

Jeff Masters

Permalink

Big money for hurricane research?

By: JeffMasters, 1:08 PM GMT en Octubre 27, 2006

The National Hurricane Research Initiative (NHRI)
There's big money proposed to fund new hurricane research. The National Science Board, in a report issued September 29, 2006, calls for an increase of $300 million per year in hurricane research funding. That's a whopping increase in funding, when one considers that the average annual spending on hurricane research has been only $20 million the past six years. So, what is the National Science Board, and this a reasonable proposal?

National Science Board
The 24 members of the National Science Board are appointed by the President of the United States, and make budget recommendations for the National Science Foundation (NSF). The NSF has an annual budget of about $5.6 billion (fiscal year 2006), and funds approximately 20 percent of all federally supported basic research conducted by America's colleges and universities. So, this is a very serious proposal by a group which has real power to influence the Federal budget.

Major recommendations of the report
The primary recommendation of the report is the formation of a National Hurricane Research Initiative (NHRI), which will "provide urgently needed hurricane science and engineering research and education". As justification for this effort, the report notes that that hurricane damage is increasing, with annual total losses (in constant 2006 dollars) averaging $1.3 billion from 1949-1989, $10.1 billion from 1990-1995, and $35.8 billion per year during the last 5 years. $168 billion in losses occurred in 2004 and 2005 alone. Over 50% of the population lives within 50 miles of the coast, and the value of infrastructure in the Gulf and Atlantic coast areas is over $3 trillion, with trillions more in investment likely in the next few decades as the U.S. population continues to expand. This incredible investment will be increasingly affected by hurricanes, and scientists "know relatively little about the most important aspects of hurricanes including their internal dynamics and interactions with the larger-scale atmosphere and ocean; methods for quantifying and conveying uncertainty and mitigating hurricane impacts; associated short and long term consequences on the natural and built environment; and the manner in which society responds before, during, and after landfall." The study notes that "billions of tax dollars have been provided for rescue, recovery, and rebuilding after hurricanes strike", but more money needs to be spent minimizing losses from hurricanes before they strike. In fact, had the NHRI been funded two years ago, much of the devastation wrought by Katrina could have been avoided. The program funds engineering studies to evaluate the structural integrity of the entire coastal infrastucture including levees, seawalls, drainage systems, bridges, water/sewage, power, and communications. The flaws in the New Orleans levees that led to over 80% of the city's flooding could have been found and fixed before Katrina hit had such a program been funded earlier.

The report has many excellent suggestions on how to make a coordinated research effort that will pay big dividends over the coming years by reducing our vulnerability to hurricanes. For example, the report seeks funding for research on improving evacuation planning, so that we can avoid a repeat of the debacle that occurred during the evacuation of Houston for Hurricane Rita. Over 100 people died in the evacuation effort. Research on improved disaster communications technologies is proposed, so that we avoid the situation that arose in Katrina where FEMA had no idea what was going on at the Convention Center.

My only gripe about the report is the inclusion of funding for research on human modification of hurricanes to reduce their intensity or alter their movement. I don't believe we should be messing with these great storms until we understand better how they work. In addition, given the sheer size and incredible energy that storms have, modification efforts will likely be an ineffectual waste of time and money. Finally, I don't think the legal system in this country will allow hurricane modification to occur without a lot of lawsuits being filed. I don't know too many hurricane scientists who are in favor of hurricane modification research, and suspect it is being funded for political reasons.

Is $300 million a reasonable request?
To do a thorough job of reducing our vulnerability to hurricanes, $300 million per year is a reasonable amount to spend. However, the U.S. faces a number of threats that also require large outlays of dollars, such as bioterrorism and earthquakes. The framers of the report realize that getting a $300 million per year project funded in a time of "increasingly small non-defense discretionary budgets" is difficult. To put this number in perspective, the annual amount spent in the U.S. on meteorology operations and supporting research is $3 billion. About $1 billion/year of this goes to run the National Weather Service, with weather satellites consuming another big chunk of the costs. But consider the amount being spent on defending the country against bioterrorism. The federal budget for bioterrorism emergency preparedness has ranged between $3 and $6 billion per year since 2002. The request for FY 2007 is $4.3 billion. That's over 200 times what we spend on hurricane research, and over ten times the $300 million being proposed. While others will disagree, I believe that the threat of catastrophe from hurricane strikes on the U.S. is much higher than that from bioterrorism. If we need to find funding for the NHRI, the bioterrorism budget can suffer a 7% cut. Another hurricane as strong as Hurricane Katrina is certain to hit a major populated area in the future, while a bioterrorism attack is not certain, and hopefully not even probable. There are wiser ways to spend our disaster preparedness dollars than what we are doing.

National Hurricane Research Initiative Act of 2006
Sen. Mel Martinez, R-Fla., introduced the National Hurricane Research Initiative Act of 2006, a bi-partisan bill that adopts the recommendations of the report. The proposed legislation puts NOAA and the National Science Foundation in charge of coordinating the research initiative. Not surprisingly, the bill is being co-sponsored by Florida's other Senator, Sen. Nelson (D-FL), and Louisiana's two Senators, Sen. Vitter (R-LA), and Sen. Landrieu (D-LA). Apparently, the Senators from the states hard hit by the hurricanes of 2004 and 2005 felt that $300 million per year wasn't enough, and ask for $435 million in funding per year through 2017.

Some historical perspective
In 1898, the United States fought the Spanish-American War. With the U.S. Navy heavily committed to operations in the Caribbean during the height of hurricane season, Willis L. Moore, Chief of the Weather Bureau, saw the need set up an improved hurricane warning system. Moore took a long view through the history of naval warfare and discovered that more armadas had been destroyed by weather than by the enemy. He placed his findings before President McKinley, and proposed that the U.S. spend money to establish a new hurricane warning service, despite the fact that budgets were tight in a time of war. McKinley responded to Moore: "I am more afraid of a West Indian hurricane than the entire Spanish Navy. Get this [hurricane warning] service inaugurated at the earliest possible moment!"

The Spanish are no longer our enemies, but the threat of hurricanes remains and will worsen if we do nothing. I hope today's politicians will emulate President McKinley, and take the long view of history. In the words of the report's conclusion:

Can we as a Nation continue to remain vulnerable to hurricanes that are an inevitable part of our future, that have demonstrated the capacity to inflict catastrophic damage to our economy, and that kill hundreds of our citizens? The hurricane warning for our Nation has been issued and we must act vigorously and without delay.

I urge you to write your Senators to support S, 4005, the National Hurricane Research Initiative Act of 2006. Those of you in Louisiana and Florida probably do not need to write your Senators--they are definitely on board on this one!

Jeff Masters

Updated: 6:33 PM GMT en Junio 30, 2009

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World Series forecast and tropical update

By: JeffMasters, 1:23 PM GMT en Octubre 26, 2006

Tonight's World Series game in St. Louis between the Tigers and the Cardinals has about a 30% chance of being rained out. A slow-moving low pressure system over the Southern Plains is expected to track across Missouri over the next two days, bring the continued chance of rain to St. Louis through Friday night. The best chance of rain is from 2am Friday through 6pm Friday, when periods of heavy rain are expected. There will be some intermittent areas of light rain and short-lived heavier showers in the area tonight, but I think the rain will not be widespread enough to cause a cancellation of the game. A rain delay of an hour or two is certainly a possibility, though. Game time temperatures should be near 48 degrees, with a light 5 mph wind blowing in from the outfield towards home. Friday's game may suffer a rain delay as well, but will likely get played.

In the Atlantic, a concentrated area of thunderstorms about 600 miles east of the Lesser Antilles Islands is associated with a westward-moving tropical wave. The region is under 20 knots of wind shear, and the shear is expected to remain too high to allow development to occur. None of the models are forecasting any significant tropical development over the next six days, and the long-range GFS model forecast no longer calls for a tropical storm to develop in the western Caribbean late next week. In the eastern Pacific, Paul has come ashore in Mexico north of Mazatlan and has dissipated. No damage or flooding problems have been reported from the storm.


The biggest storm so far this hurricane season: the storm of controversy over what was on Kenny Rogers' hand during game two of the World Series! Image of Kenny Rogers courtesy of sportsillustrated.com

I'll be back Friday with a report on a major new hurricane funding initiative introduced to the Senate. With election day fast approaching, I encourage you to ask your Senators how they plan to vote on this important issue!

Jeff Masters

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World Series rainout?

By: JeffMasters, 1:53 PM GMT en Octubre 25, 2006

Tonight's World Series game in St. Louis between the Tigers and the Cardinals has about a 60% chance of being rained out. A developing low pressure system over the Texas Panhandle is expected to pump plenty of moisture-laden air from the Gulf of Mexico northwards over Missouri today and tonight. An area of steady rain, already visible on regional radar, is moving northwards towards St. Louis, and should arrive at about 7pm local time. If the rain can hold off an extra two hours, there is chance they'll be able to play the game, but right now I'm expecting that the game will be rescheduled for Thursday. The weather outlook is a bit better for Thursday evening's game, but the low pressure system is moving slowly and will still be bringing rain and a few thunderstorms to Missouri through Friday afternoon. I give it a 30% chance of a rainout for Thursday. A rainout should act to give the Tigers a chance to regroup, get their game on track, and make this a competitive series! After the last rainout, the Tigers responded with seven straight victories.

The tropics
Tropical Storm Paul is still alive despite 30 knots of wind shear, but the severely weakened storm is not capable of causing significant damage with its 45 mph winds. Wind shear is expected to increase even more today, finishing off Paul as a tropical cyclone by Thursday, as it makes landfall along the coast of Mexico north of Mazatlan. Los Cabos radar shows just a few heavy thunderstorms near Baja.

In the Atlantic, there are no threat areas to discuss, and none of the models are forecasting tropical development over the next six days. However, the GFS model is forecasting that a tropical storm may develop in the western Caribbean late next week.


Figure 1. Latest satellite image of Paul, updated every 1/2 hour.

Jeff Masters

Updated: 2:46 PM GMT en Octubre 25, 2006

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Paul ripped in half by shear; World Series rainout for Wednesday?

By: JeffMasters, 1:53 PM GMT en Octubre 24, 2006

In the Atlantic, there are no threat areas to discuss, and none of the models are forecasting tropical development over the next six days. In the Eastern Pacific, Hurricane Paul is being torn in two by wind shear of 15-30 knots, and it appears that the storm will not cause significant damage to Mexico. Satellite loops of Paul show that the shear has torn away the upper portion of the storm, which is approaching Baja. A smaller lower-level portion has been left behind, and is quickly dissipating. Los Cabos radar shows some heavy thunderstorms approaching Baja, but I don't expect winds of more than 50 mph to affect Baja. All of the computer models are forecasting that there will be very little left of Paul by the time it reaches the coast of mainland Mexico, north of Mazatlan, on Wednesday.


Figure 1. Latest satellite image of Paul, updated every 1/2 hour.

World Series forecast
Tonight's game in St. Louis between the Tigers and the Cardinals looks to have good (but chilly) weather. Skies should be clear with light winds and a game-time temperature of 43 degrees. It's a different story on Wednesday, when a developing low pressure system is expected to bring 12 or more hours of steady rain to St. Louis beginning at about gametime. I expect an 80% chance of a rainout of Wednesday's game. The situation is a little better for Thursday, but there are going to be thunderstorms around--possibly severe--into Thursday night. I give it a 30% chance of a rainout for Thursday. Expect to see some baseball being played Friday night in St. Louis to make up for a rainout!

Jeff Masters

Updated: 8:32 PM GMT en Octubre 24, 2006

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Paul weakening

By: JeffMasters, 10:43 PM GMT en Octubre 23, 2006

In the Atlantic, there are no threat areas to discuss, and none of the models are forecasting tropical development over the next six days. In the Eastern Pacific, Hurricane Paul is forecast to pass very close to Baja Tuesday night, and then strike the coast of mainland Mexico north of Mazatlan Wednesday morning. Wind shear has incresed to 25 knots, up from 10 knots this morning, and Paul's appearance on satellite loops is much less impressive tonight. The eye is gone, the cloud pattern distorted, and the Air Force Hurricane Hunters found winds at 3:22pm EDT this afternoon of only Category 1 strength.

Paul is not yet visible on Los Cabos radar, but will be Tuesday morning. Paul will pass within 40 miles of Mexico's Socorro Island tonight. The island is hosting a group of Mexican and German Ham radio operators there for a radio operating event with many antennas up, making contact with other Ham operators around the world. They'll have plenty to talk about tonight, as winds should pick up to 60 mph, with gusts to 100 mph! Hopefully, they won't be saying, "socorro!", the Spanish word for "help".


Figure 1. Latest satellite image of Paul, updated every 1/2 hour.

Paul has begun his expected turn to the north, and is on track to recurve to the northeast, passing just south of or over the tip of the Baja Peninsula on Tuesday afternoon. Paul will be in a region of high wind shear of 25 knots or more that should significantly weaken the storm, since it is a relatively small hurricane that is vulnerable to shear. Given Paul's current organization, the storm is likely to be a Category 1 hurricane or strong tropical storm when it passes the tip of Baja. Paul should be considerably weaker at second landfall in mainland Mexico, due to wind shear plus land interaction with the mountains of Baja. The landfall in mainland Mexico will be in the same sparsely populated region that Category 3 Hurricane Lane hit last month, and significant damage and casualties are much less of a threat than for Paul's possible impact on Baja.

Jeff Masters

Updated: 10:45 PM GMT en Octubre 23, 2006

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Paul continues to strengthen

By: JeffMasters, 2:27 PM GMT en Octubre 23, 2006

In the Atlantic, there are no threat areas to discuss, and none of the models are forecasting tropical development over the next six days. In the Eastern Pacific, Hurricane Paul is forecast to pass very close to Baja Tuesday afternoon, and then strike the coast of mainland Mexico north of Mazatlan Tuesday night. Paul is under only about 10 knots of shear this morning, and his satellite appearance has continued to improve. The eye has become better defined the past six hours, and with shear expected to remain below 20 knots until tonight, Paul has a chance to become a Category 3 hurricane with 115 mph winds by Tuesday morning. The Air Force Hurricane Hunters will investigate Paul this afternoon.

Paul is not yet visible on Los Cabos radar, but will be tonight. Paul will pass within 60 miles of Mexico's Socorro Island today. The island is hosting a group of Mexican and German Ham radio operators there for a radio operating event with many antennas up, making contact with other Ham operators around the world. They'll have plenty to talk about tonight, as winds should pick up to 60 mph, with gusts to 100 mph! Hopefully, they won't be saying, "socorro!", the Spanish word for "help".


Figure 1. Latest satellite image of Paul, updated every 1/2 hour.

Paul has begun his expected turn to the northwest this morning, and is on track to recurve to the northeast, passing just south of or over the tip of the Baja Peninsula on Tuesday afternoon. The latest (6Z) run of the GFDL model forecasts Paul will make a direct hit on San Lucas and San Jose del Cabo with 105 mph winds. The earlier run (00Z) had Paul just missing Baja to the south. The northern portion of Paul will be in a region of high wind shear near 30 knots beginning Tuesday morning, and most of the global computer models forecast that this shear will rapidly weaken Paul, since he is a small hurricane that is potentially vulnerable to shear. The Canadian model takes the weakening to an extreme and dissipates Paul before the storm reaches Baja. However, the GFDL model, which has outperformed the other models for Paul, continues to show that Paul will remain a Category 2 hurricane until final landfall on mainland Mexico. Given Paul's current organization, I think it likely the storm will be able to maintain Category 2 status when it passes the tip of Baja. Paul should be considerably weaker at second landfall in mainland Mexico, due to wind shear plus land interaction with the mountains of Baja. The landfall in mainland Mexico will be in the same sparsely populated region that Category 3 Hurricane Lane hit last month, and significant damage and casualties are much less of a threat than for Paul's possible impact on Baja.

Jeff Masters

Updated: 2:45 PM GMT en Octubre 23, 2006

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Paul threatens Mexico; World Series weather in Detroit

By: JeffMasters, 3:50 PM GMT en Octubre 22, 2006

In the Atlantic, there are no threat areas to discuss, and none of the models are forecasting tropical development over the next six days. In the Eastern Pacific, Tropical Storm Paul is forecast to pass very close to Baja as a tropical storm on Tuesday and then strike the coast of mainland Mexico. Paul is under only about 10 knots of shear this morning, and his satellite appearance has shown as a modest improvement since last night. The shear is expected to remain below 20 knots through Monday, which may give Paul enough time to strengthen to a Category 1 hurricane. Shear is expected to increase on Monday, significantly weakening Paul before he makes landfall in Mexico. The GFDL model is still predicting that Paul will become a major hurricane, but the rest of the models do not agree with this. The other models' forecast of a weakening Tropical Storm Paul at landfall in Mexico Tuesday seem more reasonable, given the 20+ knots of shear expected to impact the storm beginning Monday.

A QuikSCAT pass from 9:22am EDT today showed Paul's top winds at about 50 mph. It is interesting to compare this image (the standard 25 km resolution product) with the high resolution 12.5 km QuikSCAT image of the same region. The high-resolution product suffers from more ambiguity about which direction the winds are blowing, and sometimes the algorithm to detect which direction the winds are blowing gets it wrong. The winds on the south side of Paul in the high-resolution 12.5 km QuikSCAT are exactly the opposite of what they should be.

World Series forecast
It looks like some nasty weather for the Tigers and Cardinals tonight, with a game-time temperature of 40 degrees, occasional rain showers, and 15-20 mph winds. The wind should be from the west-northwest, from home plate towards left field (take a look at the orientation of Comerica Park with respect to the wind). This will favor the home-run hitting possibilities for right-handed sluggers like Albert Pujols and Magglio Ordonez. Snow may mix in with the rain late in the game. I doubt the rain showers will be heavy enough to force a rain delay.

Jeff Masters

Updated: 4:18 PM GMT en Octubre 22, 2006

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Paul in Mexico; World Series weather in Detroit

By: JeffMasters, 4:30 PM GMT en Octubre 21, 2006

The area of disturbed weather near Puerto Rico (90L) has become disorganized, and tropical storm formation is no longer a threat from this system. In the Pacific, Tropical Storm Paul has the potential to be a serious threat to Baja on Monday and mainland Mexico on Tuesday. The 2am EDT run of the GFDL model intensified Paul into a major Category 3 hurricane with 115 mph winds just south of Baja on Monday. While this forecast is probably too aggressive based on the GFDL forecasts I've seen for the other Pacific Mexican hurricanes this season, I do think it is likely Paul will become a hurricane by landfall, and could cause extensive damage if it hits a populated area.

World Series forecast
In another matter of weather concern for the U.S. and Caribbean, tonight's World Series baseball game looks like it will be mostly rain-free. A strong cold front is expected to move in late tonight, bringing heavy rain after 1am to Detroit. Today's game time temperature should be about 48 degrees, and wind will be about 10 mph out of the southwest--blowing from right field towards left field. There are some scattered rain showers that may affect the game today, but I doubt these will be strong enough to cause a rain delay.

Jeff Masters

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Heavy rains continue in Puerto Rico and northern Lesser Antilles

By: JeffMasters, 1:46 PM GMT en Octubre 20, 2006

An area of low pressure just northeast of Puerto Rico (90L), continues to spread heavy rain and gusty winds over the northern Lesser Antilles islands. Wind shear over the disturbance has dropped to 10 knots, and is forecast to stay below 20 knots the next two days, which may allow some slow development. The storm has not become any better organized over the past day, however. A QuikSCAT satellite pass last night revealed no well-defined closed circulation, and top winds were just 15-25 mph. Unfortunately, the Puerto Rico radar failed Wednesday. There are two television stations on the island that maintain radars--televicentropr.com (click on "Super Doppler Max" and wait for the animation to load) and Univision (click on "El Tiempo" and scroll to the bottom.) The Univision radar had not updated for 15 hours when I checked this morning. Gracias to Hector Ivan Soto Nazario, P.E. ASCS, Vice President of the Central Industrial Cleaning Corp. of Guaynabo, Puerto Rico, who provided me these handy links.

Flood watches have been posted this morning in eastern Puerto Rico and the Virgin Islands, where up to five inches of rain fell yesterday. Additional heavy rains are expected today, and 90L will also bring heavy rains and potential flash flooding to the much of the northernmost Lesser Antilles Islands and eastern Puerto Rico over the next day.

Visible satellite animations show that 90L is pushing slowly northeastward out to sea. This motion is expected to continue over the next few days, and 90L will likely not trouble any more land areas by Saturday night. Yesterday afternoon's run of the GFDL model did intensify 90L into a tropical storm, but none of the other models are doing so. I expect the system is too small and disorganized to become a tropical storm.


Figure 1. Preliminary model tracks for disturbance "90L".

Elsewhere in the tropics
None of the computer models are forecasting tropical development in the Atlantic over the next six days. Some of the models show the possibility of a tropical storm forming along the Pacific coast of Mexico early next week and moving towards Baja, but this has a low probability of happening.

I'll be back with an update Saturday morning. For those of you interested, there have been some good posts on the "View from the Surface" blog this month--an interview with Dr. Kerry Emanuel of MIT, plus a review of his excellent book, The Divine Wind; a report on a recent Nature magazine article accusing NOAA of suppressing the views of scientists who link intense hurricanes with climate change; and also today's game of guess the quote from the hurricane article.

Jeff Masters

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Tropical disturbance 90L causing floods in the Virgin Islands

By: JeffMasters, 2:36 PM GMT en Octubre 19, 2006

An area of low pressure over the Virgin Islands, just east of Puerto Rico (90L), has gotten better organized this morning. Wind shear over the disturbance has dropped to 20 knots, and is forecast to stay in the 15-25 knot range over the next few days, which may allow some slow development. A QuikSCAT satellite pass at 6:04am EDT revealed a substantial wind shift associated with the low, but no well-defined closed circulation. Top winds from QuikSCAT were in the 25-30 mph range. Unfortunately, the Puerto Rico radar failed Wednesday, and the Martinique radar is too far away to see most of the thunderstorm activity.

Flood warnings have been posted this morning on St. Croix in the Virgin islands, where 4 inches of rain has fallen in four hours. Additional heavy rains are expected today, and 90L will also bring heavy rains and potential flash flooding to the rest of the Virgin Islands and eastern Puerto Rico over the next two days.

Visible satellite animations show that the disturbance is not moving much, but it is expected to push slowly northward over the next two days. After that, the NOGAPS and UKMET models predict a slow motion to the west-northwest towards the Bahama Islands. The GFS model prefers a due north track, and the other models (Figure 1) call for a more northeasterly track. By the middle of next week, a trough of low pressure should sweep 90L northeastwards out to sea. The disturbance is too small and under too much wind shear to develop into a tropical depression, in all likelihood.


Figure 1. Preliminary model tracks for disturbance "90L".

Elsewhere in the tropics
The NOGAPS model is showing a weak tropical storm forming in the southern Caribbean Tuesday. None of the other models are showing this, and given the lack of consistency of the NOGAPS's predictions of late, this forecast is not credible.

Most of the models show the possibility of a tropical storm forming along the Pacific coast of Mexico early next week and moving towards Baja. This is a believable forecast.

I'll be back with an update Friday morning.

Jeff Masters

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Quiet tropics; the globe experiences its 4th warmest September on record

By: JeffMasters, 1:16 PM GMT en Octubre 18, 2006

It's a quiet Wednesday in the tropics. A weak low pressure system near Puerto Rico is kicking up some showers, but this system is under 30 knots of wind shear and is not expected to develop. Wind shear is expected to be relatively light across the Caribbean and southern Gulf of Mexico most of the coming week, and the NOGAPS model is forecasting that a tropical storm will form in the southern Caribbean on Saturday. The storm is forecast to move northwards, threatening Jamaica, the Cayman Islands, and Cuba early next week. None of the other models are picking up on this, and the NOGAPS has been wrong once before this month on a similar type of forecast. Residents of the Caribbean, south Florida, and the Bahamas should keep an eye on possible development later this week, but I doubt that we'll see a tropical storm in the Caribbean like the NOGAPS model is forecasting.

An unusually cool September in the U.S.
The U.S. experienced its first month with below normal temperatures in over two years last month, according to the National Climatic Data Center September summary. September 2006 was the 31st coolest September dating back to 1895, and the first month with below-normal temperatures since August 2004. Still, January to September was the warmest such year-to-date period on record in the U.S. The nationally averaged year-to-date temperature was 58.3F (14.6C), a full 1F above the record set just last year in 2005. Interestingly, the United States was the only region of the globe that saw significantly cooler than normal temperatures in September (Figure 1). September 2006 was the 37th wettest September on record in the U.S., and Kentucky had its wettest September ever. The cool weather in the U.S. was due to a southward dip of the jet stream over the nation; this jet stream pattern also acted to steer September's hurricanes away from the U.S. and out to sea.


Figure 1. Temperature departure from normal for September 2006.

Globally, the 4th warmest September on record
While the U.S. cooled off in September, the rest of the globe stayed hot. September 2006 was the 4th warmest September globally since records began in 1880 (1.0F/0.56C above the 20th century mean). January to September 2006 was the 4th warmest such period on record. Global ocean temperatures for September were the 3rd warmest on record, thanks in part to an El Nio episode that began in September. Sea ice extent in the Arctic was the second lowest on record this September. The record low was set in 2005.

Jeff Masters

Updated: 1:38 PM GMT en Octubre 18, 2006

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Flooding swamps the Gulf Coast

By: JeffMasters, 1:28 PM GMT en Octubre 17, 2006

A frontal system accompanied by copious moisture pumped in by tropical disturbance 92L dumped prodigious rains on the Gulf states yesterday. Rainfall totaled 14 inches in some regions of Texas and Louisiana (Figure 1), triggering flooding that killed three people in the Houston area. The victims challenged flood waters in their vehicles, and lost. Parts of Interstates 10 and 45 were shut down around Houston, and the University of Houston and several other schools were closed. The storm system also spawned numerous tornadoes which caused a few injuries and scattered damage. At 3am yesterday, a tornado ripped into a boat yard in Leeville, LA, hurling boats around, flipping two mobile homes, and injuring four people. Tornadoes also hit Lumberton, China, and Magnolia Beach in Texas. The threat of tornadoes continues today across the coastal regions of Alabama and the Florida Panhandle, but should diminish by this afternoon as the atmosphere finally starts to stabilize.


Figure 1. Total estimated rainfall from the Lake Charles radar.

Elsewhere in the tropics
There's nothing going on, anywhere in the world. Later this week, most of the models forecast that a weak tropical storm will form in the central Atlantic northeast of Puerto Rico and move out to sea. Wind shear is expected to be light across the Caribbean and southern Gulf of Mexico most of the week, and the NOGAPS model is forecasting that a tropical storm will form in the southern Caribbean on Friday. The storm is forecast to move northwards, threatening Jamaica, the Cayman Islands, and Cuba early next week. None of the other models are picking up on this, and the NOGAPS has been wrong once before this month on a similar type of forecast. Still, residents of the Caribbean, south Florida, and the Bahamas should keep an eye on possible development later this week.

I'll be back with an update Wednesday morning.

Jeff Masters

Updated: 1:45 PM GMT en Octubre 17, 2006

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Gulf of Mexico disturbance creating dangerous floods and tornadoes

By: JeffMasters, 1:43 PM GMT en Octubre 16, 2006

The tropical disturbance (92L) that formed over the Gulf of Mexico this weekend has moved inland over Texas. The storm is affecting Texas, Louisiana, and Mississippi much like a tropical storm would. An upper-level trough of low pressure is interacting with 92L and bringing very heavy rains, flooding, and tornadoes. The Houston NWS weather discussion from this morning calls this a "very dangerous heavy rain event". Four to six inches of rain have already fallen over some coastal regions, with another 3-5 inches expected today. With high winds and high tides over the Gulf, draining of rivers along the coast is being hampered, adding to the flooding problems. The disturbance is generating sustained winds of tropical storm force over the Gulf of Mexico. Buoy 42362 off the coast of Louisiana has seen sustained winds of 45 mph with higher gusts this morning. Numerous waterspouts and tornadoes have been spawned in some of the heavier thunderstorms. At 3am this morning, a tornado ripped into a boat yard in Leeville, LA, hurling boats around, flipping two mobile homes, and injuring four people. Tornadoes have also been reported in Lumberton, China, and Magnolia Beach in Texas this morning, with some damage reported. Radar in Lake Charles, LA is showing numerous severe thunderstorms with possible tornadoes this morning. Heavy rains in coastal Mississippi triggered floods this morning in Waveland, forcing evacuations in that city, which was mostly destroyed by Hurricane Katrina.


Figure 1. Total estimated rainfall from 92L measured by the Houston radar.

Elsewhere in the tropics
The tropical disturbance just north of Puerto Rico (90L) is under 20 knots of wind shear, and should get torn apart by Tuesday. The disturbance will bring heavy thunderstorm activity to portions of Puerto Rico today. We'll have to watch the Gulf of Mexico this week, as shear is expected to remain low and more disturbances like 92L may develop.

I'll be back with an update Tuesday morning.

Jeff Masters

Updated: 1:47 PM GMT en Octubre 16, 2006

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Gulf of Mexico disturbance generating storng winds

By: JeffMasters, 4:02 PM GMT en Octubre 15, 2006

A non-tropical low pressure area is in the Gulf of Mexico just off the coast of Mexico, about 250 miles south of Brownsville, Texas. This disturbance was designated 92L by NHC last night, and does have a small chance of developing into a tropical storm. The heavy thunderstorm activity associated with this low has shown a modest increase this morning as the low has moved northwards along the coast at about 10 mph. A buoy 275 miles south-southeast of Sabine, Texas has seen winds near tropical depression strength this morning--30 mph, gusting to 40 mph. Unfortunately, this morning's QuikSCAT pass missed 92L, and we'll have to wait until 10:30pm EDT tonight for the next pass. Long-range Brownsville radar is showing considerable shower activity over South Texas and the adjacent Gulf of Mexico waters. However, there is no hint of banding features indicative of a low-level circulation, and no surface circulation is apparent on visible satellite loops of the Gulf of Mexico.

The disturbance is still under about 15 knots of shear, which is low enough to allow development into a tropical storm. The shear is forecast to remain at about 15 knots for the next two days, although there is much higher shear just to 92L's north that could create hostile conditions for development if the storm moves too quickly to the north. There may be some reduction of this shear, though, created by Tropical Depression Norman, which is making landfall on the other side of Mexico on the Pacific coast.

I'm not expecting 92L to become a tropical storm, but it should bring very heavy rains and winds gusts of tropical storm force to the coasts of Texas and Louisiana Monday and Tuesday. The Hurricane Hunters are not scheduled to visit 92L at all.


Figure 1. Preliminary model tracks for the Gulf of Mexico disturbance, 92L.

Elsewhere in the tropics
The tropical disturbance just north of Puerto Rico (90L) is under 30 knots of wind shear, and should get torn apart by Tuesday. However, the disturbance will bring heavy thunderstorm activity to portions of Puerto Rico and the Dominican Republic today and Monday.

I'll be back with an update Monday morning.

Jeff Masters

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Gulf of Mexico disturbance 92L spins up

By: JeffMasters, 2:09 AM GMT en Octubre 15, 2006

A non-tropical low pressure area has developed in the Gulf of Mexico just off the coast of Mexico, about 300 miles south of Brownsville, Texas. This disturbance has been designated "92L" by NHC this evening, and does have a small chance of developing into a tropical storm. If it does develop, it would likely move north-northeast and strike the coast of Texas or Louisiana on Monday or Tuesday. The pressure has fallen significantly at Tuxpan, Mexico, and was 1005 mb at 7pm EDT. Winds over the waters just offshore the Mexican coast were as high as 40-50 mph in this morning's QuikSCAT pass, but were only 15-20 mph in this evening's 8:11pm EDT pass. A new QuikSCAT pass is due at 10am EDT Sunday. The satellite appearance of 92L has degraded markedly in the past few hours, with most of the heavy thunderstorm activity moving far east away from the center. There is very little shower activity associated with 92L visible on long-range Brownsville radar this evening. Unfortunately, the Mexican radar for this region has been down since September 3.

The disturbance is under about 15 knots of shear this evening, which is low enough to allow development into a tropical storm. However, the storm is moving towards an area of much higher shear (40 knots!), and this higher shear may cause significant trouble for the disturbance. Shear is forecast to drop significantly in the Gulf beginning Monday, so there may be a window of opportunity that day for 92L to grow into a tropical storm. I'm really not expecting this to become a tropical storm, but if it does, it would likely not have time to grow to more than a 50-mph storm.


Figure 1. Preliminary model tracks for the Gulf of Mexico disturbance, 92L.

I'll ba back with an update late Sunday morning.

Jeff Masters

Updated: 2:21 AM GMT en Octubre 15, 2006

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A quiet weekend for the tropics

By: JeffMasters, 1:55 PM GMT en Octubre 13, 2006

The disturbance just north of Puerto Rico (90L) has been torn apart by wind shear and is no longer a threat to develop. Tropical Depression 4-C that was headed towards Hawaii has been torn apart by wind shear and is no longer a threat to the islands. An area of disturbed weather over the western Gulf of Mexico is under 40 knots of wind shear, and is not a threat to develop through Sunday. By Monday, however, shear is expected to drop significantly in the Gulf, and we will have to watch this area for development.

Elsewhere in the tropics
The models continue to show the possibility of a tropical storm forming along the Pacific coast of Mexico early next week, possibly from the remains of Tropical Storm Olivia.

I'll have an update Sunday morning.

Jeff Masters

Updated: 3:27 PM GMT en Octubre 14, 2006

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Puerto Rico disturbance fizzles; Hawaii disturbance slowly organizing

By: JeffMasters, 8:54 PM GMT en Octubre 12, 2006

An area of disturbed weather (90L) over the northern Lesser Antilles Islands has lost most of its heavy thunderstorm activity this morning and is no longer a threat to develop into a tropical depression in the next two days. Wind shear is a low 10 knots over the disturbance, and is expected to remain below 10 knots for the next two or three days, so the disturbance does still have a chance to develop by Sunday. However, there is quite a bit of dry air to the west, which may distrupt any heavy thunderstorm activity that tries to form. Wind shear is expected to rise significantly beginning on Sunday, and the long term prospects for 90L to become a tropical storm in the Caribbean are low.

Puerto Rico radar shows only disorganized thunderstorm activity at present. Winds in the northern Lesser Antilles Islands have been unspectacular so far today--no more than 15 mph at St. Kitts, St. Maartin, and Antigua. The morning pass of the QuikSCAT satellite missed 90L; we'll have to wait until about 9pm EDT tonight for the next pass. Satellite imagery and surface reports show that no surface circulation exists.

Most of the computer models forecast a track over the northern Lesser Antilles Islands the next two days, with the disturbance moving over Puerto Rico Saturday morning and the Dominican Republic on Saturday night. The system is being drawn northwest by a strong trough of low pressure passing to the north of the islands. However, it appears that this trough is not strong enough to pull 90L out to sea, and high pressure should build in and force the storm westward by Sunday.


Figure 1. Preliminary model tracks for disturbance "90L".

Hawaii
Residents of Hawaii should continue to watch an area of disturbed weather (97C) near 9N, 166W, about 1000 miles southwest of the Hawaiian Islands. A QuikSCAT satellite pass from 12:56am EDT this morning showed a closed surface circulation, and some wind barbs of 40-45 mph to the south of the center. The thunderstorm activity has gotten a little better organized today. Wind shear has remained about 15 knots today, which is low enough to allow some continued slow development. Sea Surface Temperatures (SSTs) are about 29C, and there is a very deep pool of warm water underneath to fuel intensification. The last two runs of the GFDL model have predicted that 97C will become a tropical storm that could threaten Hawaii by Tuesday.


Figure 2. Preliminary model tracks for disturbance "97C".

Elsewhere in the tropics
The models continue to show the possibility of a low pressure system forming in the Gulf of Mexico near the Texas coast early next week. This low will probably be non-tropical, though. Several models are calling for a tropical storm to develop along the Pacific coast of Mexico by Monday and move northwest towards Baja. Baja does not need to worry about Tropical Depression Olivia, which is expected to dissipate Friday before reaching Baja.

I'll have an update Friday morning.

Jeff Masters

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Caribbean disturbance a threat to Puerto Rico; Hawaii needs to keep an eye on the tropics

By: JeffMasters, 2:09 PM GMT en Octubre 12, 2006

An area of disturbed weather (90L) over the northern Lesser Antilles Islands expanded significantly in size overnight, but has lost most of its heavy thunderstorm activity this morning. Wind shear is 10 knots over the disturbance, and is expected to remain below 10 knots for the next two or three days. Water temperatures are about 29 degrees C, which is plenty warm for a tropical cyclone. There is quite a bit of dry air to the west, which may distrupt any heavy thunderstorm activity that tries to form. Martinique radar shows considerable thunderstorm activity, but the activity is pretty disorganized at present. Winds in the northern Lesser Antilles Islands have been unspectacular so far today--no more than 15 mph at St. Kitts, St. Maartin, and Antigua. The morning pass of the QuikSCAT satellite missed 90L; we'll have to wait until about 9pm EDT tonight for the next pass. It is difficult to tell from satellite imagery or surface reports if 90L has a surface circulation. Due to the collapse of heavy thunderstorm activity this morning, it now appears unlikely 90L will become a tropical depression in the next two days.

Most of the computer models forecast a track over the northern Lesser Antilles Islands the next two days, with the disturbance moving over Puerto Rico Saturday morning and the Dominican Republic on Saturday night. The system is being drawn northwest by a strong trough of low pressure passing to the north of the islands. However, it appears that this trough is not strong enough to pull 90L out to sea, and high pressure should build in and force the storm westward by Sunday. The storm still has a chance to become a tropical depression early next week if it can avoid Hispaniola. However, wind shear is expected to rise over the Caribbean beginning on Sunday, and this may put an end to the threat.


Figure 1. Preliminary model tracks for disturbance "90L".

Hawaii
Residents of Hawaii should continue to watch an area of disturbed weather (97C) near 9N, 166W, about 1000 miles southwest of the Hawaiian Islands. A QuikSCAT satellite pass from 12:56am EDT this morning showed a closed surface circulation, and some wind barbs of 40-45 mph to the south of the center. The thunderstorm activity has gotten more intense over the past day, but is still disorganized. Wind shear has increased to about 15 knots today, but this is still low enough to allow some slow development. Sea Surface Temperatures (SSTs) are about 29C, and there is a very deep pool of warm water underneath to fuel intensification. Both the GFDL and NOGAPS models forecast that 97C will become a strong tropical storm or Category 1 hurricane that will threaten the Hawaiian Islands on Monday night or Tuesday.


Figure 2. Preliminary model tracks for disturbance "97C".

Elsewhere in the tropics
The models continue to show the possibility of a low pressure system forming in the Gulf of Mexico near the Texas coast early next week. This low will probably be non-tropical, though. Several models are calling for a tropical storm to develop along the Pacific coast of Mexico by Monday and move northwest towards Baja. Baja does not need to worry about Tropical Depression Olivia, which is expected to dissipate Friday before reaching Baja.

I'll have an update later today if 90L or 97C show significant change.

Jeff Masters

Updated: 3:30 PM GMT en Octubre 12, 2006

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New disturbance 90L entering the Caribbean; Hawaii needs to watch 97C

By: JeffMasters, 1:53 PM GMT en Octubre 11, 2006

A small area of disturbed weather with heavy thunderstorm activity and an apparent surface circulation (90L) is centered near the island of Barbados this morning. A buoy about 150 miles northeast of the center of 90L recorded sustained winds of 35 mph with higher gusts last night. Winds from the QuikSCAT satellite pass from 5:45am EDT this morning showed winds as high as 30 mph. QuikSCAT also showed what may be a closed circulation at the surface. Winds at Barbados shifted to westerly this morning at 8am AST, confirming that 90L probably has a surface circulation. Martinique radar shows little thunderstorm activity so far, but this should increase this afternoon as 90L moves through the Lesser Antilles Islands and the heavier showers come in range of the radar. Winds so far today in Martinique have been below 10 mph.

In the disturbance's favor are a moist environment, low wind shear of 5-10 knots, and warm water temperatures of 83 degrees F. The main inhibiting factor is probably 90L's very small size. Disturbances this small have trouble developing into tropical storms, since they are very fragile and require near-perfect environmental conditions. The storm does not have a perfect environment; visible satellite loops from this morning show a competing circulation a few hundred miles to the east of Barbados interfering with 90L's organization. Still, 90L does have a chance to develop, since wind shear is forecast to remain below 10 knots for the next three days over the Caribbean. However, wind shear increases dramatically just north of the Caribbean, so if 90L moves north of Puerto Rico, it will likely be quickly destroyed. Most of the models forecast a west-northwest track for 90L over the next few days. Puerto Rico and the Dominican Republic should expect to feel 90L's rain and winds on Friday and Saturday. It's possible 90L could develop into a 50 mph tropical storm by that time. It is very unlikely 90L will intensify into a hurricane. The most likely scenario is for 90L to remain a tropical disturbance, or become a tropical depression that never organizes into a tropical storm.


Figure 1. Preliminary model tracks for disturbance "90L".

Hawaii
Residents of Hawaii should to continue watch an area of disturbed weather (now called 97C) near 8N, 167W, about 900 miles southwest of the Hawaiian Islands. A QuikSCAT satellite pass from 1:23am EDT this morning showed a closed surface circulation, and some wind barbs of 40-45 mph to the south of the center. The thunderstorm activity has gotten more intense over the past day, but is still very disorganized. The system is currently under about 10 knots of winds shear, and is underneath an upper-level anticyclone. Sea Surface Temperatures (SSTs) are about 29C, and there is a very deep pool of warm water underneath to fuel intensification. These are all very favorable conditions for development. SSTs stay above 26C all the way to Hawaii, and a landfalling hurricane in the islands is a possibility a week or so from now. The 6Z (2am EDT) run of the GFDL model intensified 97C into a hurricane by Sunday. However, the more recent 12Z (8am) run did not develop 97C at all.


Figure 2. Preliminary model tracks for disturbance "97C".

Elsewhere in the tropics
The models continue to show the possibility of a low pressure system forming in the Gulf of Mexico near the Texas coast early next week. This low will probably be non-tropical, though. The models are now less enthused about a new hurricane developing along the Pacific coast of Mexico and threatening Baja next week. Baja does not have to worry about Tropical Storm Norman, which dissipated last night, nor Tropical Depression Olivia, which is expected to dissipate Friday before reaching Baja.

I'll have an update later today if 90L or 97C show significant change.

Jeff Masters

Updated: 6:51 PM GMT en Octubre 11, 2006

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New disturbance 90L entering the Caribbean Wednesday

By: JeffMasters, 1:21 AM GMT en Octubre 11, 2006

Heavy thunderstorm activity has increased this evening in association with an area of disturbed weather a few hundered miles east of the Lesser Antilles Islands. A buoy about 150 miles north of the center of the disturbance has seen an increase in wind speed over the past 12 hours, and the winds tonight are now 30 mph with higher gusts. However, the pressure at this buoy is not falling. Unfortunately, winds from the QuikSCAT satellite are not available in the region tonight, and we will have to wait until about 9am EDT for another pass. We should also have wind reports from some of the islands Wednesday afternoon as the disturbance moves through.

Wind shear is a low 10 knots over the disturbance, and is forecast to remain below 10 knots for the next three days over the Caribbean. This may allow the disturbance to develop. None of the computer models develop the disurbance yet, but that may change by morning.


Figure 1. Preliminary model tracks for disturbance "90L".

Hawaii
Hawaii needs to continue watch an area of disturbed weather (now called 97C) near 9N, 163W, about 700 miles southwest of the Hawaiian Islands. Its thunderstorm activity has gotten better organized today, and system has the potential to develop into a tropical depression by Thursday. The system is currently under about 10 knots of winds shear, and is underneath an upper-level anticyclone. Sea Surface Temperatures (SSTs) are about 29C, and there is a very deep pool of warm water underneath to fuel intensification. These are all very favorable conditions for development. SSTs stay above 26C all the way to Hawaii, and a landfalling hurricane in the islands is a possibility a week or so from now.


Figure 2. Preliminary model tracks for disturbance "97C".

I'll have an update by 10am EDT Wednesday.

Jeff Masters

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Hawaii and Mexico need to keep a wary weather eye

By: JeffMasters, 1:46 PM GMT en Octubre 10, 2006

It's an El Nino year in the Pacific, which means that Hawaii and the Pacific coast of Mexico are at increased risk of hurricane landfalls this month. Hawaii needs to watch an area of disturbed weather (now called 97C) near 9N, 165W, about 700 miles southwest of the Hawaiian Islands. Its thunderstorm activity is disorganized this morning, but 97C has the potential to develop into a tropical depression by Thursday. The two latest runs of the GFDL model have brought 97C to hurricane status by early next week, with a northward track towards Hawaii. The system is currently under about 10 knots of winds shear, and is underneath an upper-level anticyclone. Sea Surface Temperatures (SSTs) are about 29C, and there is a very deep pool of warm water underneath to fuel intensification. These are all very favorable conditions for development. SSTs stay above 26C all the way to Hawaii, and a landfalling hurricane in the islands is a possibility a week or so from now.


Figure 1. Preliminary model tracks for disturbance "97C".

Elsewhere in the tropics
A low pressure system a few hundred miles off the coast of North Carolina is non-tropical, and is not expected to become tropical as it moves northeast parallel to the coast. This system could bring heavy rain to Cape Cod and the Maritime provinces of Canada later this week. Some of the models are hinting that a low pressure system could form in the Gulf of Mexico off the Texas coast early next week. If this storm forms, it could be non-tropical. The models are also forecasting the possibility of a hurricane forming along the Mexican Pacific coast early next week, and moving parallel to the coast towards Baja. However, the two current storms approaching Baja, Tropical Depression 16E and Tropical Storm Norman, are both expected to dissipate before reaching Baja, due to high wind shear and cool waters.

Jeff Masters

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Dr. Suppresso

By: JeffMasters, 2:08 PM GMT en Octubre 09, 2006

The tropical Atlantic remains quiet. A non-tropical low pressure system off the coast of North Carolina today is expected to intensify and move northeastward this week. This low should remain non-tropical, but could gain some tropical characteristics and give Nova Scotia heavy rain on Friday. None of the computer models are forecasting any tropical storm development in the Atlantic this week, and the flow pattern reminds me more of November than October.

Interview with Hurricane Specialist Dr. Jack Beven
With hurricane season winding down, it's time to pay tribute to the forecasters at the National Hurricane Center that have done such an excellent job over the years. You've seen the familiar signatures at the bottom of the National Hurricane Center advisories--Avila, Beven, Stewart, Franklin, Pasch, and Knabb (and this year, joined by five new names!) It's these hurricane specialists that form the bedrock of the superb NHC hurricane forecasts. They are fantastic at what they do, and I rely heavily on their expertise. I'll be doing profiles of two of the forecasters this hurricane season, so you can see the faces behind the names.

"Beven" is Dr. John L. Beven II, one of the six senior hurricane specialists at the NHC. Jack, 45, has been working at the Hurricane Center since 1988. He started then as an intern while working on his Ph.D., and landed one of the coveted hurricane specialist jobs in 1993.

Jack graduated in 1984 from Louisiana State University with a Bachelor's in Physics. He got his Masters degree in Meteorology in 1988 from Florida State, and continued on for his Ph.D. in 1994. His advisor was Dr. T.N. Krishnamurti, famous for his numerous research achievements in tropical meteorology, including development of the FSU Superensemble tracking model for hurricanes. Jack's Ph.D. thesis was titled, "Tropical Cyclone-Environmental Interactions During Recurvature - A Modeling and Observational Study".



I got a chance to catch up with Jack this April at a conference in Monterey, and asked him a few questions:

Q:What is your most memorable experience with a hurricane on the ground?

A: Well, back in 1985 while I was in graduate school at FSU, Hurricane Kate came ashore. A bunch of us grad students found a place by the west door of the Love Building sheltered from the wind, and took turns running into the wind.

Q: What do you do in your free time?

I like to go storm chasing! I take a yearly trip out to Oklahoma and chase tornadoes. I'm also a big Dr. Who fan, and enjoy sports, particularly college football, college basketball, and college baseball.

Q: Do you have any comments you'd like to make about the global warming issue?

A: I think there's a lot of room for both natural and man-made effects in the current way the climate is changing.

Jack has the nickname "Dr. Suppresso" among his storm chaser friends, thanks to the tendency for promising supercell thunderstorms to suddenly die out when he approaches--or for an expected outbreak of severe thunderstorms to completely fail, due to a strong capping inversion. With that kind of ability, we need to have him intercepting hurricanes at the coast, instead of writing advisories!

Jeff Masters

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Quiet in the Atlantic

By: JeffMasters, 3:40 PM GMT en Octubre 08, 2006

The tropical Atlantic is quiet today. An area of thunderstorms off the coast of South Carolina is due to an upper level low pressure system. This system is under only 10 knots of wind shear, but will not be around long enough to develop into a tropical depression. Strong westerly winds will carry the disurbance out to sea over cooler waters over the next few days.

An area of disturbed weather over the eastern Bahamas is associated with an upper-level trough. Wind shear is extremely high--40 knots--and this disurbance will not develop.

The models are not predicting any tropical storm formation this week.

It's an El Nino year quiet time in the Atlantic, so enjoy another quiet Sunday, everyone!

Jeff Masters

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Quiet in the Atlantic

By: JeffMasters, 3:09 PM GMT en Octubre 07, 2006

An area of disturbed weather (99L) near 35N, 67W, about 200 miles north-northwest of Bermuda, remains disorganized, and is not a threat to develop into a tropical depression. The Hurricane Hunter flight scheduled for today was canceled. Radar animation from Bermuda shows just a few disorganized showers over the waters near the island. QuikSCAT satellite winds from this morning show a well-defined surface circulation, but top winds of only 20-25 mph near the center. The system is expected to move eastward over the open Atlantic.

Elsewhere in the tropics
An area of disturbed weather over the southern Gulf of Mexico has diminished, and is no longer a threat to develop. A new area of disturbed weather has formed in the western Caribbean just north of Honduras. This disturbance is under 20-30 knots of wind shear, so is not a threat to develop today. The disturbance may bring heavy rain and gusty winds to Belize and Mexico's Yucatan Peninsula tonight and Sunday as it moves west-northwest at 15 mph. On Monday, wind shear may drop below 20 knots over the western Caribbean and extreme southern Gulf of Mexico. If today's disturbance is still around then, it may be able to take advantage of the lower shear and show some slow development. However, the models are less aggressive about their forecast of low shear over the Caribbean, and I expect that wind shear will be too high to allow any tropical storms to develop over the Caribbean or Gulf of Mexico this week. We will need to keep an eye on the area between the Bahamas and Bermuda this week, though--several of the models are forecasting that a low pressure system will develop in this region by Tuesday, and such a low could turn into a tropical or subtropical storm.

Jeff Masters

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New disturbance 99L near Bermuda headed out to sea

By: JeffMasters, 1:54 PM GMT en Octubre 06, 2006

An area of disturbed weather near 30N, 70W, about 300 miles southwest of Bermuda, has been designated "Invest 99L" by the National Hurricane Center this morning. Radar animation from Bermuda shows a large area of heavy rain over the ocean to the east of the island. This area of disturbed weather is moving to the north-northeast, and is expected to turn eastward this weekend. Some of 99L's heavy thunderstorms may affect Bermuda tonight and Saturday. The QuikSCAT satellite pass at 6:15am EDT this morning found a large, well-defined surface circulation, and peak winds in the 20-25 mph range. The disturbance is under 30 knots of wind shear from strong upper-level westerly winds. This shear is preventing heavy thunderstorms from building on the west side of 99L. Wind shear is expected to be in the 20-40 knot range for the next two days. The disturbance is over warm waters of 28 degrees C, but water temperatures cool rapidly to 26C just north of Bermuda. Between the wind shear and cooler waters, I doubt 99L has time to organize into a tropical or subtropical depression.


Figure 1. Preliminary model tracks for disturbance "99L".

Elsewhere in the tropics
An area of disturbed weather continues over the southern Gulf of Mexico, but is not expected to develop due to 20 knots of wind shear. High wind shear dominates most of the rest of the tropical Atlantic. This shear is forecast to relax early next week over the Caribbean and southern Gulf of Mexico, so we'll have to keep an eye on these regions next week.

Jeff Masters

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High wind shear dominates the Atlantic

By: JeffMasters, 1:48 PM GMT en Octubre 05, 2006

There are two areas of heavy thunderstorms over the Atlantic worth mentioning today. One area, over the southern Gulf of Mexico, is under 20-30 knots of vertical wind shear (Figure 1). Wind shear is expected to increase to very high levels over the Gulf over the next week (Figure 2), and there will be no tropical development there. The second area is between the Bahamas and Bermuda. Wind shear is also a high 20-30 knots in this region, and is expected to remain at about this level over the next few days. QuikSCAT imagery from this morning shows some winds of tropical storm strength, but no evidence of a surface circulation or even a wind shift in this area. Some of the computer models are forecasting that a low pressure system will develop in this area sometime in the next week, but it appears that this low will probably be extratropical.

Next week, we'll have to keep an eye on the Caribbean. Wind shear is expected to drop to low levels (Figure 2), and any tropical waves or cold fronts that move into the region might have the potential to develop. However, I'm not expecting any development.

Figure 1. Wind shear from 8am EDT today, as forecast by last night's 00Z (8pm EDT) GFS model run. The red areas show areas less than 16 knots of wind shear, which are favorable for tropical storm formation. The wind units are in meters per second; a rough rule of thumb is that 1 m/s = 2 knots. The high levels of wind shear over most of the tropical Atlantic is typical of what we see in October during an El Nino year.


Figure 2. Seven-day wind shear forecast for 8am EDT Wed October 11, as forecast by last night's 00Z (8pm EDT) GFS model run. The red areas show areas less than 16 knots of wind shear, which are favorable for tropical storm formation. The wind units are in meters per second; a rough rule of thumb is that 1 m/s = 2 knots. While most of the tropical Atlantic is expected to be under high wind shear, a "hole" in the shear is expected to open over the Caribbean.

Jeff Masters

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Dr. Bill Gray's final 2006 forecast issued

By: JeffMasters, 1:33 PM GMT en Octubre 04, 2006

The tropical Atlantic is quiet today. The computer models are indicating some development is possible early next week in the region between the Bahamas and Bermuda, but this is likely to be extratropical in nature.

Latest hurricane forecast by Dr. Bill Gray
The final 2006 seasonal forecast for the Atlantic hurricane season by the Colorado State University team led by Dr. Bill Gray and Phil Klotzbach was issued yesterday. The new forecast calls for two named storms in October, one of which is a hurricane, which is not expected to be intense. Gray's team forecasts no named storms for November, noting that November tropical cyclones are rare in the Atlantic during El Nio events. The average level of October activity is 1.6 named storms and 1.1 hurricanes. These averages decline by about 1/3 in El Nio years, to 1.3 named storms and 0.7 hurricanes. No intense (or major) hurricanes have been observed to form after 1 October in El Nio years since 1950. Dr Gray's team gives the following odds for landfalls along the U.S. coast in October 2006:

Named storm: 22%
Hurricane: 14%
Intense hurricane: 4%

The average probabilities of landfalling October tropical cyclones in the U.S. the past 52 years looked like this:

Named storm: 29%
Hurricane: 15%
Intense hurricane: 6%

The authors note that the failure of the El Nio prediction models to properly forecast the rapidly developing El Nio event this year was a major reason why their earlier hurricane forecasts were inaccurate. August-September 2006 sea surface temperatures in Equatorial Eastern Pacific warmed by approximately 0.6C from their June-July values, which is the greatest increase ever observed in a year that wasn't already seeing an El Nio event (the increase was 0.9C during strongest El Nio on record, in 1997; however, 1997 was already a strong El Nio event by the beginning of the summer).

I posted my October hurricane outlook yesterday, which calls for just one named storm for the Atlantic the remainder of hurricane season.

Jeff Masters

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October hurricane season outlook

By: JeffMasters, 2:24 PM GMT en Octubre 03, 2006

Hurricane Isaac is no more. The storm skirted the southeast coast of Newfoundland, bringing wind gusts up to 60 mph to the island. No damage was reported.

It's a different story in the aftermath of Typhoon Xangsane for the Philippines and Vietnam. These countries suffered heavily from Xangsane. The death toll has risen to 207 in the Philippines, with hundreds injured, 146,000 homes damaged or destroyed, and 171,000 people left homeless. In Vietnam, the death toll has risen to 42, 1200 are injured, and heavy flooding is still a serious problem. Xangsane destroyed or unroofed 200,000 houses in Vietnam, causing at least $300 million in damage.

The tropical Atlantic is quiet
A non-tropical low pressure system is about 500 miles south of the Azores Islands. This low may gradually acquire tropical characteristics over the next few days as it drifts over the open Atlantic.

The computer models are indicating some development is possible by Thursday in the region between the Bahamas and Bermuda, along an old cold front. Any development here would probably move northeast out to sea, and could be a threat to Bermuda.

October Atlantic hurricane season outlook
We're in the home stretch now! For the first time since 1997, we've made it through September without a landfalling hurricane in the Atlantic (Ernesto and Florence came close, but didn't hit land as hurricanes). We now have only two more weeks of peak hurricane season left. While the season technically ends November 30, we can see that hurricane season slows down drastically around October 18 (Figure 1), thanks to increasing wind shear, cooling Sea Surface Temperatures (SSTs), and an end to the tropical waves coming off the coast of Africa. With no major changes expected to the steering patterns or general atmospheric conditions over the Atlantic the next few weeks, I believe that we will go the remainder of this season without a landfalling hurricane in the Atlantic. It still pays to be vigilant, though--recall that at this time last year, Hurricane Stan was killing 1500 people in Central America, and we still had ten more named storms to go, including the strongest hurricane of all time, Wilma.


Figure 1. Climatological hurricane and tropical storm activity for the Atlantic.

Steering pattern
The steering pattern for October over the Atlantic will remain similar to what we've seen all of hurricane season. The jet stream is expected to stay active, bringing frequent troughs of low pressure over the Atlantic that will act to recurve any storm that approaches the Caribbean or U.S. East Coast. This pattern has been in place since early June. As we progress deeper into October, the troughs grow stronger and extend further south, making it very unlikely anything developing between Africa and the Lesser Antilles Islands will make landfall. Any landfalling storms will have to form from the the remains of old fronts that push off the U.S. coast.

Dry air
Dry air should not be as detrimental for tropical cyclone formation in October compared to previous months. The Saharan Air Layer (SAL) is most prevalent over the Atlantic in June and July, and is usually not in evidence much in October. The current SAL image shows very little dry air over the tropical Atlantic. The SAL is pretty much confined to the waters near the African coast. The 2-week outlook from the GFS model shows near-normal SAL activity, with no major SAL episodes over the tropical Atlantic.

Wind shear and El Nio
Wind shear over most of the tropical Atlantic has been near or below normal since early July. Climatologically, wind shear reaches its minimum in September, which is the same time that SSTs reach their peak. In October, wind shear normally begins to rise, which one can see in the plot for the eastern Caribbean (Figure 2, black line). The blue line in Figure 2 shows that in the past few days, wind shear has spiked to above normal values, and this is also occurring throughout the rest of the tropical Atlantic. This appears to be a temporary increase for the Caribbean; the latest 2-week wind shear outlook from the GFS model shows below-normal shear over most of the Caribbean next week. However, wind shear over the Gulf of Mexico and remainder of the tropical Atlantic is expected to be higher than normal the next two weeks.

Part of this increase in wind shear is probably due to El Nio. An El Nio event was officially declared by NOAA's Climate Prediction Center on September 13, when SSTs in the Equatorial Eastern Pacific reached +0.5C above normal, the threshold for a weak El Nio. El Nio continues to strengthen, and SSTs are almost a full degree Centigrade above normal now, the threshold for a moderate El Nio. SSTs are forecast to continue much above normal (Figure 3) through the next six months (if they increase to 2C above normal, then this will qualify as a strong El Nio event). It is well known that El Nio events tend to suppress Atlantic hurricane activity by increasing upper level westerly winds at about 40,000 feet (200 mb). These strong westerly winds create a high wind shear that prevents tropical storms from forming.

Sea Surface Temperatures
Sea Surface Temperatures in the tropical Atlantic are slowly cooling now that it is October, but are still 0.5 - 1 C above normal. These above normal temperatures are expected to persist through the remainder of hurricane season (Figure 3).


Figure 2. Observed wind shear in 2006 (blue line) and climatological wind shear (black line) for the eastern Caribbean. Image credit: NOAA/CIRES.

Figure 3. NOAA's Sea Surface Temperature forecast for the next four months. Note the much warmer than normal SSTs over the Equatorial Eastern Pacific, indicating a moderate El Nio event occurring. Note also that SSTs are expected to remain 0.5 - 1 C above normal over the tropical Atlantic for the remainder of hurricane season.

Conclusion
Because of high wind shear over the Atlantic due to the expected jet stream pattern and a strengthening El Nio event, I am forecasting at most two more named storms this year and no hurricanes. I think it most probable we will get just one more named storm. The steering pattern we've seen all hurricane season is not expected to change much, so any storm forming during the remainder of the season is likely to stay over water. If we do get a landfalling storm, the most likely targets are the Carolinas, Bermuda, or the Gulf Coast of Florida. Perhaps the best analogue year to compare with is 1997, a strong El Nio year, when we had two 45-mph tropical storms form in October. Neither of these storms hit land.

Jeff Masters

Updated: 2:40 PM GMT en Octubre 03, 2006

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Isaac races through Newfoundland

By: JeffMasters, 1:37 PM GMT en Octubre 02, 2006

Hurricane Isaac is racing towards the southeast corner of Newfoundland at 35 mph, and will bring winds near hurricane force to the island today. Already this morning, winds have reached 36 mph with higher gusts at Sagona Island, Newfoundland. Sagona Island saw sustained winds of 76 mph gusting to 93 during the passage of the extratropical version of Hurricane Florence on September 13. Isaac's impact on Newfoundland will probably be similar to that of Florence, which destroyed one home and caused scattered power outages and minor damage. A 2-3 foot storm surge and 2-3 inches of rain are likely from Isaac.


Figure 1. Latest satellite image of Isaac, updated every 1/2 hour.

Elsewhere in the tropics
An non-tropical low pressure system has formed near 30N 30W, about 500 miles south of the Azores Islands. This low may gradually acquire tropical characteristics over the next few days as it drifts southwestward over warmer waters.

The computer models are indicating some development is possible by Thursday in the region between the Bahamas and Bermuda, along an old cold front. Any development here would probably move northeast out to sea, and could be a threat to Bermuda.

I'll haven't had a chance to finish my October tropical outlook, but hope to post that Tuesday morning.

Jeff Masters

Updated: 1:43 PM GMT en Octubre 02, 2006

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Vietnam bashed by Xangsane; Isaac headed to Newfoundland

By: JeffMasters, 4:22 PM GMT en Octubre 01, 2006

Typhoon Xangsane slammed ashore the central Vietnamese coast just south of Dan Nang Sunday morning as a Category 2 storm. The eye passed just south of Dan Nang, sparing Vietnam's 4th largest city the worst of the eyewall's winds. Da Nang had its winds rise to 63 mph with higher gusts at the peak of the storm, and the weather station was able to stay operational throughout the typhoon. At least ten deaths have been reported in Vietnam so far, and thousands of houses were reported damaged or destroyed. Xangsane is not expected to be a prodigious rainmaker. Forecast 24-hour forecast rain amounts from NOAA's Satellite Analysis Branch (Figure 2) were mostly 2-8 inches. Xangsane has degenerated to a remnant low today, and advisories are no longer being issued on the storm.

In the Philippines, the death toll is 76, with 69 people still missing. Power is still out to over 12 million people on the Philippines' main island of Luzon, including nearly half the residents of the capital of Manila.


Figure 1. Typhoon Xangsane at landfall in Vietnam. Image credit: NOAA/NESDIS.


Figure 2. Expected 24-hour rain amount from Typhoon Xangsane. Image credit: NOAA.

Hurricane Isaac
Hurricane Isaac has peaked in intensity, and is now weakening thanks to higher wind shear from a trough of low pressure to its northwest. Isaac is expected to get absorbed by the trough on Monday and make the transition to a powerful extratropical storm. Isaac will bring winds near hurricane force to southeastern Newfoundland on Monday night. Isaac's impact on Newfoundland will probably be similar to that caused by the remains of Hurricane Florence in September--Florence destroyed one home and caused scattered power outages and minor damage.

Elsewhere in the tropics
An area of intense thunderstorms has developed about 600 miles southwest of the Cape Verdes Islands. This area is under about 15 knots of wind shear today, and the shear is expected to increase to 30 knots tomorrow, which should halt any development. Elsewhere, there's nothing to remark upon.

I'll have an update Monday morning.

Jeff Masters

Updated: 4:23 PM GMT en Octubre 01, 2006

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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