Bill intensifies to Category 4; globe has 5th warmest July on record

By: Dr. Jeff Masters , 3:28 PM GMT en Agosto 19, 2009

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Category 4 Hurricane Bill is now the the fourth strongest tropical cyclone to appear on the planet so far this year, and may grow even stronger. Visible and infrared satellite imagery continue to show an impressive, well-organized, hurricane, with plenty of low-level spiral banding and upper-level outflow well-established on all sides except the west. On Bill's west side, upper-level winds from the west are creating a modest 10 knots of wind shear, which is giving the hurricane a bit of a squashed appearance there.

Wind shear is forecast to remain low to moderate, 5-15 knots, for the next four days. Sea Surface Temperatures (SSTs) will rise steadily from 28.5°C today to 29°C on Friday. Total ocean heat content is at a maximum today, and will gradually decline over the next four days. Bill should be able to take advantage of these favorable conditions a remain a major hurricane the next three days.


Figure 1. Visible satellite image from NASA's Aqua spacecraft at 12:40pm EDT Tuesday August 18, 2009. Image credit: NASA GSFC.

Water vapor satellite loops show a small "short-wave" trough of low pressure to the north-northwest of Bill, and this trough has turned Bill on a more northwesterly track over the past two days. Bill will miss the Lesser Antilles Islands, and the main impact of the hurricane on these islands will be high waves. The short wave trough (so called because it has a relatively small amplitude and wavelength) is not strong enough to turn Bill due north, and Bill is also expected to miss Bermuda. High waves and sustained winds of 20 - 30 mph are the worst that Bermuda is likely to get from Bill.


Figure 2. Visible satellite image of Bill's eye zoomed in, taken from NASA's Aqua spacecraft at 12:40pm EDT Tuesday August 18, 2009. Image credit: NASA GSFC.

An unusually strong "long wave" trough of low pressure (called long wave because of its large amplitude and wavelength) is expected to develop along the U.S. East Coast late this week. This trough will turn Bill to the north, and also bring high levels of wind shear in the 40 - 65 knot range on Sunday. Exactly where this turn occurs is still not clear. The models continue to be in two camps: an eastern camp (GFS, GFDL, HWRF, and ECMWF) that takes Bill 300 - 500 miles east of Cape Cod, and a more western camp (NOGAPS, UKMET) that bring Bill within 150 - 200 miles of Cape Cod. Both sets of models bring Bill ashore over the Canadian provinces of Newfoundland or Nova Scotia. Bill will be weakening rapidly as it makes landfall, and is likely to be a Category 1 hurricane if it hits Nova Scotia, or strong tropical storm if it hits Newfoundland.

Bill's big waves
Large swells from Bill will begin impacting the U.S. East coast from Florida to Maine beginning Friday night or Saturday morning. Seas will build to 5 - 10 feet in the offshore waters from central Florida northwards to South Carolina, and to 10 - 15 feet from North Carolina to Cape Cod. Near shore, waves will be about 40% less. This will cause a significant coastal erosion event along some portions of the coast. The latest run of the NOAA Wavewatch III model suggests that significant wave heights near Bill's center will reach 50 feet on Sunday. Since maximum wave height is typically about a factor of 1.9 greater than the significant wave height (which is the average trough-to-crest height of the top 1/3 largest waves), a few huge waves near Bill's center may reach 95 feet high.

Possible impacts to New England
The current set of computer model runs predicts that the center of Bill will pass Cape Cod, Massachusetts Sunday afternoon or evening. Tropical storm-force sustained winds of 39 mph or greater currently extend out 185 miles to the west of Bill's center, so that if Bill maintains its current wind distribution, Cape Cod could see sustained winds of about 40 mph Sunday night if the models predicting a more westerly path are correct. However, Bill will not keep this same radius of winds. The hurricane will weaken considerably beginning Sunday morning, once the storm gets caught up in the approaching long wave trough. High wind shear of 40 - 65 knots due to strong southwesterly winds aloft will act to compress the hurricane in the east-west direction, keeping the hurricane's strongest winds away from Cape Cod. The highest winds are likely to be no more than 30 mph on Cape Cod from Bill, if the storm follows the track of the western camp of models nearest to the Massachusetts. A few rain squalls may affect coastal Massachusetts, but the main impact of Bill on New England is likely to be coastal erosion from high waves.

Elsewhere in the tropics
The remains of Tropical Storm Ana are bringing scattered heavy rain showers to the Bahamas and Florida today. The remains are disorganized, and are not likely to re-develop. The only model calling for a new tropical cyclone to develop in the Atlantic over the next seven days is the GFS model, which predicts development off the coast of Africa about 7 days from now.

Fifth warmest July on record globally; a cold July in the U.S.
The globe recorded its fifth warmest July since record keeping began in 1880, according to NOAA's National Climatic Data Center. NOAA rated the period January - July 2009 as the sixth warmest such period on record. NASA's Goddard Institute for Space Studies rated July 2009 as the 2nd warmest July on record, behind July of 1998. For the second month in a row, global ocean Sea Surface Temperatures (SSTs) in July were the warmest on record, 0.59°C (1.06°F) above the 20th century average. This broke the previous July record set in 1998. The record July SSTs were due in part to an ongoing El Niño event in the Eastern Pacific, which has substantially warmed a large stretch of the tropical Eastern Pacific Ocean. As El Niño conditions mature during the coming months, near-record global ocean and land temperatures will probably continue. Now that El Niño conditions have been well-established for three months, the atmosphere has begun to heat up in response. It typically takes up to seven months for the atmosphere to heat up in response to ocean heating from an El Niño. This may explain why June of 2009, which independent assessments by NOAA, NASA, and the UK Hadley center agreed was the 2nd or 3rd warmest June on record at the surface, recorded only average satellite-measured temperatures in the lower atmosphere. In contrast, the July satellite-measured temperatures in the lower atmosphere were the 2nd or 3rd warmest on record, in agreement with the assessments that surface temperatures were the 2nd to 5th warmest on record.


Figure 3. Departure of temperature from average for July 2009. Image credit: NOAA/NCDC.

A cold July for the U.S.
For the contiguous U.S., the average July temperature of 23.1°C (73.5°F) was the coolest since 1994, and July temperatures were the 27th coolest in the 115-year record, according to the National Climatic Data Center. Ohio, Illinois, Indiana, Pennsylvania, Iowa, and West Virginia experienced their coolest ever July. Kentucky, Missouri, Michigan, and Wisconsin recorded their second coolest July in history. A strong trough of low pressure parked itself over the eastern portion of the U.S. in July, funneling down plenty of cold air from Canada. In the western U.S., a ridge of high pressure dominated, bringing unusually hot conditions. Arizona recorded its 3rd warmest July on record, and Seattle, Washington recorded its hottest day in history on July 28, notching a 103°F reading. This was 3°F above the previous record set in 1994.

U.S. precipitation was near average in July, with the month ranking 40th wettest in the 115-year record. U.S. tornado activity was above average in July, according to NOAA's Storm Prediction Center. However, no tornado deaths occurred in July.

At the end of July, 14% of the contiguous United States was in moderate-to-exceptional drought. This is a drop from the 19% figure observed at the beginning of the year. These extreme drought regions were exclusively in South and Central Texas.

I'll have an update Thursday morning.

Jeff Masters

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Quoting 21N71W:
Morning All,
Are we safe now in the Bahamas and in the Turks and Caicos.....one more day of worry maybe?
No worrying necessary at this point. Bill would find it impossible to trek due west at this time.
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Additional banding wrapping around the west. Seems SW shear is not having much of an impact at present time.
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Buoy 41044 - 21.652 N 58.695 W
To the East of Bill




Buoy 41049 27.500 N 63.000 W
NNW'ish of Bill

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Blog not extremely active today. Have people given up on Bill??
Member Since: Junio 29, 2009 Posts: 13 Comments: 5313
Complete Graphics Update:
HURRICANE BILL 5 am NHC Advisory
**Tropical Storm Watch may be required for Bermuda later today

My Bill Projected Path (from 8 pm last night):

TROPICAL DEPRESSION GUILLERMO (Final Advisory-11 pm last night)

TYPHOON VAMCO
Member Since: Junio 29, 2009 Posts: 13 Comments: 5313
This morning's IR of Bill looks very similar to yesterday morning's IR. Been recovered impressively on long loop it seems.
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Bill is getting stronger.
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Some interesting excerpts from NWS NYC's area forecast discussion...

A COLD FRONT WILL PUSH SLOWLY TOWARDS THE AREA FRIDAY NIGHT AND
SATURDAY. DYNAMICS IN MESOSCALE MODELS FAVORABLE FOR A NEARLY
STATIONARY BAND OF MODERATE TO HEAVY RAIN...WITH THE MAIN AXIS
ACROSS NORTHERN NJ AND THE LOWER HUDSON VALLEY THRU SATURDAY
AFTERNOON. IF ALL INGREDIENTS COME TOGETHER...RAINFALL RATES OF 2
INCHES PER HOUR ARE POSSIBLE. HOWEVER...THE GLOBAL MODELS (GFS/EC)
NOT HITTING THIS SETUP AS HARD. IT SHOULD ALSO BE NOTED THAT THIS
IS NOT A RAIN BAND DIRECTLY ASSOCIATED WITH HURRICANE BILL
...AND
HAS ITS OWN JET SUPPORT. LACK OF CONFIDENCE IN TIMING AND
PLACEMENT PRECLUDE THE ISSUANCE OF ANY HEADLINES AT THIS
TIME...BUT WILL CONTINUE TO MENTION IN THE HWO.

BASED ON THE LATEST FORECAST FROM TCP...BILL WILL CONTINUE TO TRACK
A FEW HUNDRED MILES TO THE SOUTH AND EAST OF MONTAUK POINT SUNDAY
MORNING
. FOR THE LATEST AND MOST UP TO DATE INFORMATION...REFER TO
FORECASTS/ADVISORIES ISSUED BY TCP. AT THIS TIME...THE MAIN
THREAT TO THE AREA WILL BE HIGH SURF/BEACH EROSION/DEADLY RIP
CURRENTS
...AND MINOR COASTAL FLOODING OVER THE WEEKEND. IT IS
WORTH NOTING THAT THE RADIUS OF 12 FT SEAS EXTENDS SOME 300 MILES
FROM THE CENTER OF THE STORM
...THUS THE IMPACTS DUE TO WAVE ACTION
WILL BE FAR REACHING.
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2112. 21N71W
Morning All,
Are we safe now in the Bahamas and in the Turks and Caicos.....one more day of worry maybe?
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Quoting Category5hitsNewYork:

I think this will be a trend with the other models. The shortwave shall weaken and it will pull a new england hurricane. The track should be shifted westward. I would not be surprised to see a NNW movement with this storm on Saturday


In that case the shortwave would grow stronger more quickly than anticipated...the deeper it gets, the slower it would move.
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Quoting cycloone:
i remember they had predicted the loop pretty good beforehand
Really? I don't think so at all. http://www.nhc.noaa.gov/archive/2004/JEANNE_graphics.shtml
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Quoting NEwxguy:
Still feel fairly safe here in eastern Mass,but this thing is going to be a little close for comfort,if that trough is slower than they thought,things could change in a hurry


That trough is already slower then NHC thought.
And it is not there yet.
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Quoting Ossqss:
Just remember folks, be prepared regardless. The models provide forecast positions, they are not called surecast positions for a reason.

Patraps blog can provide valuable information and also the link on the main tropical page on WU for OneStorm, which is a very helpful guided helper for you to create a complete plan including important check lists and logged contact info and action plan etc. It walks you through the whole process and you will have a better comfort level with your situation with the information provided. I did anyhow. You will need to register to use the site.

www.onestorm.org

http://www.onestorm.org/Default.aspx?ReturnUrl=/OnePlan/


Even a direct landfall on my state by a Category 1 would have devastating effects...most people here are convinced it can't happen, which of course is a deadly assumption.
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Good morning!
Member Since: Junio 29, 2009 Posts: 13 Comments: 5313
Morning everyone! Slight risk for us in north NJ with the approaching shortwave...



It looks to me like the 06z GFS run is intensifying the shortwave far quicker than in previous runs, causing it to slow down forward motion and nudging Bill a bit further west. Portions of South New England/Cape Cod may briefly fall into the TS wind field if this forecast plays out.

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2101. Ossqss
Just remember folks, be prepared regardless. The models provide forecast positions, they are not called surecast positions for a reason.

Patraps blog can provide valuable information and also the link on the main tropical page on WU for OneStorm, which is a very helpful guided helper for you to create a complete plan including important check lists and logged contact info and action plan etc. It walks you through the whole process and you will have a better comfort level with your situation with the information provided. I did anyhow. You will need to register to use the site.

www.onestorm.org

http://www.onestorm.org/Default.aspx?ReturnUrl=/OnePlan/
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2100. NEwxguy
Still feel fairly safe here in eastern Mass,but this thing is going to be a little close for comfort,if that trough is slower than they thought,things could change in a hurry
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2099. bjdsrq
Quoting islandblow:
href="C:\Users\Lennox\Pictures\DSC_0099.JPG"Link
Dont know if this comes out and its really history now, but it shows the heavy seas outside my house yesterday on the Atlantic coast of Dominica with Bill over 700 miles away.


You can't link photos from your local machine's hard drive and expect people on the internet to see it. You'll need to post the photo to your WU photo account.
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Good morning

While Bill is the only game in town there is an area of interest near 11N 23W in the form of a weak surface low that is starting to develop convection. Something else to keep an eye on IMO
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Quoting cajunmoma:



Lol...True!!


LOL wrong, it'll take longer to pump out the subway system, and the salt water will eat up the concrete, which will have to totally rebuilt!
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2094. bjdsrq


Very little, still going to make landfall/skirt eastern nova scotia (where i live) :(


Regardless, the right front quad will be *well* offshore, along with the most interesting weather.
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Link

Dont know if this comes out and its really history now, but it shows the heavy seas outside my house yesterday on the Atlantic coast of Dominica with Bill over 700 miles away.
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According to the Weather Channel we have something called the "Wonder Jet Stream" and "Wonder Trough" that will absolutely and positively keep Bill off shore and out to sea. I believe there was no mention of Nova Scotia and thereabouts as being affected. Most of the models ram all that surge right up the Bay of Fundy. So the Wonder Jet is their theme for the day. So we can all quit worrying. Right? Right???????
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2090. IKE
Quoting IMA:


You'd never know it here in south-central TX! We're looking at triple digits, still - broke our record, by over 10 days, for most # of days in the triple digits. It's freakin' miserable!


True. Looked at San Antonio's forecast....upper 90's to near 100 the next 7 days. Most of the cooler air will be east of there.

Calling for mid 60's here in the inland Florida panhandle for Saturday and Sunday night. High's near 90.
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GFS last four cycles
Red = 06Z
Blue = 00Z
Green = 18Z
Brown = 12Z

Member Since: Septiembre 23, 2005 Posts: 14 Comments: 11179
2087. IMA
Quoting IKE:
Fall is getting closer. From the Birmingham,AL. discussion...

"...UNSEASONABLY COOL AIRMASS MOVES IN. EXPECT TEMPERATURES TO RUN
WELL BELOW NORMAL FOR BOTH THE DAYTIME AND NIGHTTIME PERIODS. SOME
LOCATIONS MAY SEE UPPER 50S ON BOTH SUNDAY AND MONDAY MORNING."


You'd never know it here in south-central TX! We're looking at triple digits, still - broke our record, by over 10 days, for most # of days in the triple digits. It's freakin' miserable!
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2086. K8eCane
i was thinking they shifted east also ike
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2084. Sting13
Quoting StormW:
Good morning!

Just got on...haven't looked at anything yet.

Did the models shift at all?


Very little, still going to make landfall/skirt eastern nova scotia (where i live) :(
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2083. IKE
Looks like they shifted east to me....

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2082. K8eCane
hi storm!
glad you came in
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Where's the latest GFS ensembles?
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2079. IKE
Fall is getting closer. From the Birmingham,AL. discussion...

"COLD FRONT IS SET TO MOVE ACROSS THE AREA ON FRIDAY. EXPECT THE
THREAT FOR SOME ISOLATED STRONG THUNDERSTORMS TO CONTINUE.

DRY CONDITIONS WILL THEN PREVAIL OVER THE WEEKEND AS AN
UNSEASONABLY COOL AIRMASS MOVES IN. EXPECT TEMPERATURES TO RUN
WELL BELOW NORMAL FOR BOTH THE DAYTIME AND NIGHTTIME PERIODS. SOME
LOCATIONS MAY SEE UPPER 50S ON BOTH SUNDAY AND MONDAY MORNING.
"
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2078. Engine2
Good Morning StormW - They are holding steady maybe a slight shift westward - us here on Long Island are hoping they stay out of our area
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Quoting breald:


Wasn't Jeanne thew one that did all kinds of loops and turn before it move ashore?
i remember they had predicted the loop pretty good beforehand
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Quoting apocalyps:


I disagree,every day the models have taken Bill a little closer to the Eastcoast.
If this lasts one more day there is something going to be hit.
I agree almost every day the models are moving around and especialy the Ensemble models. They're predicting a New England landfall.
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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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