Little change to Tomas as it bears down on Haiti
Tropical Storm Tomas is headed north towards Haiti, and the northernmost spiral bands of the storm have already reached the tip of Haiti's southwestern peninsula, the eastern tip of Jamaica, and eastern Cuba. It appears at this time that the most dangerous flooding rains of 5 - 10 inches will be confined to the southwestern and northwestern peninsulas of Haiti, and that the earthquake zone where 1.3 million people live in makeshift shelters and tents will experience lesser rains that will cause serious but not catastrophic flooding. Satellite loops of Tomas show an average-sized tropical storm with a modest amount of heavy thunderstorm activity and low-level spiral bands. Upper-level outflow is good to the north, fair to the east, and poor elsewhere. Wind shear as diagnosed by the University of Wisconsin CIMSS group is a moderate 10 - 20 knots. The shear is due to strong upper-level winds out of the southwest, and the shear is keeping most of Tomas' heavy thunderstorms pushed over to the northeast side of the storm. The low-level center of circulation has been exposed to view most of the afternoon, the tell-tale sign of a tropical storm struggling with wind shear. The areal coverage and intensity of Tomas' thunderstorms has continued to grow this afternoon, but Tomas' winds and pressure have remained about the same. A 2:31pm center fix by an Air Force hurricane hunter aircraft found a central pressure of 999 mb--several millibars higher than early this morning. Top surface winds of 57 mph were seen with their SFMR instrument. Rainfall amounts as observed by the Metopa polar orbiting satellite at 10:23am were 0.5 - 1.0" per hour in a 100-mile wide region near the center of Tomas (Figure 1.) One odd aspect of Tomas is that the area of low pressure 200 - 300 miles southwest of Tomas has gotten better defined with an steady increase in heavy thunderstorm activity this afternoon. This movement of energy to the southwest is probably responsible for the 3 mb rise in Tomas' pressure over the past three hours. It is possible, but not likely, that Tomas' center could relocate 200 miles to the south-southwest later tonight, resulting in a 12 hour longer period of rainfall for Haiti, eastern Cuba, the Dominican Republic, and Jamaica.
Figure 1. Rainfall rate for Tomas as observed by the Metopa polar orbiting satellite at 10:23am EDT Thursday, November 4, 2010. Heaviest rainfall rates in excess of 0.5 inches per hour (green colors) were confined to a 100-mile wide area near the core of Tomas. Image credit: Navy Research Lab, Monterey.
Track and rainfall forecast for Tomas
A trough of low pressure over the Eastern U.S. is drawing Tomas northward at 7 mph, and this forward speed will gradually increase to 10 mph late tonight. Heavy rains from Tomas will spread over all of Haiti, western portions of the Dominican Republic, and eastern Cuba by tonight. Satellite-based estimates of current rainfall rates from Tomas (Figure 2) yield predictions of 2 - 4 inches of rain falling over an 18-hour period near the core of Tomas. This forecast only uses the current intensity of the storm to come up with a rainfall forecast, and if Tomas intensifies today, rainfall amounts will be higher. Tomas has an elongated band of heavy rains that extend all the way to South America, so I expect that the southwest and northwest peninsulas of Haiti will receive heavy rains until Saturday night or Sunday morning. Taking these factors into account, plus the current track forecast, I expect that the heaviest rains from Tomas will fall over these two peninsulas, and accumulate to 5 - 10 inches. Precipitation amounts over Haiti's earthquake zone and the western Dominican Republic will be 3 - 5 inches, with some isolated areas receiving up to 8 inches. The most severe flooding problems from Tomas will probably be in Haiti's southwestern Peninsula, and in the city of Gonaives in northwest Haiti, where most of the 3,000 deaths from Hurricane Jeanne's rains in 2004 occurred. The NHC rainfall forecast for 1 to 3 inches over Jamaica, 3 to 5 inches over eastern Cuba, the southeastern Bahamas, and the Turks and Caicos Islands looks good.
Figure 2. Predicted rain amounts for the 18-hour period ending at 2am EDT Friday, November 5, 2010, as forecast using satellite-derived measurements of precipitation rates. Image credit: NOAA/NESDIS.
Figure 3. Predicted cumulative rainfall from Tomas as predicted by the 8am EDT (12Z) Thursday, November 4, 2010 run of the GFDL model. The model predicts no rainfall amounts in excess of 8 inches (yellow colors) for Haiti. Image credit: Morris Bender, NOAA/GFDL.
The computer models now agree that the trough of low pressure pulling Tomas northward will be strong enough to pull Tomas well north of the Bahamas, and the storm will not stall out near Hispaniola for many days as was being predicted by many of the models yesterday. Wind shear will rise to the high range, 35 - 60 knots, by Sunday, resulting in a steady weakening of Tomas.
Intensity forecast for Tomas
Tomas continues to have difficulty disentangling itself from an area of low pressure over the southwest Caribbean, and this low is acting to steal moisture from Tomas and distort its circulation. As Tomas pulls away from this low, these effects will lessen, and Tomas may be able to intensify into a minimal Category 1 hurricane before reaching the Turks and Caicos Islands and southeastern Bahamas. Wind shear as predicted by the SHIPS model will remain in the low to moderate range, 5 - 15 knots, through Saturday afternoon, which should allow for some modest intensification. NHC is giving Tomas a 43% chance of reaching hurricane strength by Friday evening.
Comparison with Hurricane Ernesto of 2006
Tomas's current position and intensity are similar to that of Tropical Storm Ernesto of 2006. Ernesto was a small to moderate-sized tropical storm with 50 mph winds when it hit the southwestern tip of Haiti on August 27. According to Wikipedia, In Haiti, the storm caused heavy rainfall of over 11 inches (300 mm) and strong winds, causing flooding and destroying 13 homes on the island of La Gonave. In Port-au-Prince, rainfall severely damaged a bridge, isolating the southern portion of the region. Across the country, 59 homes were damaged, of which six destroyed, and a total of five deaths were reported..
Tomas is a larger and wetter storm than Ernesto , and I expect that Tomas' rains in Haiti will be about 25% greater than Ernesto's. Since Haiti is more vulnerable to disasters because of the floods of 2008 and the 2010 earthquake, the rains from Tomas will cause more death and destruction than Ernesto did, but I don't expect a catastrophe with many hundreds of deaths in Haiti's earthquake zone. Such a catastrophe is possible in southwest or northwest Haiti, however.
Figure 4. Track of Hurricane Ernesto in 2006.
Organizations Active in Haitian Relief Efforts:
Portlight disaster relief
Lambi Fund of Haiti
Haiti Hope Fund
Catholic Relief Services of Haiti
Next update
I'll have an update Friday morning.
Yesterday's post on Haiti's hurricane history is now a permanent link in the "Articles of interest" section on our Tropical & Hurricane web page.
Jeff Masters
Reader Comments
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You can see what i am talking about at the Ramsis loop above.......DANG
There are mountains of rubble, broken glass and other projectiles scattered everywhere down there. A piece of corrugated metal flying at 60,70+ miles an hour can take your head clean off. And like I said its everywhere!
00
WTNT41 KNHC 050838
TCDAT1
HURRICANE TOMAS DISCUSSION NUMBER 29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010
500 AM EDT FRI NOV 05 2010
TOMAS HAS REGAINED HURRICANE STRENGTH. THE AIR FORCE HURRICANE
HUNTERS FOUND A PEAK 850 MB FLIGHT-LEVEL WIND OF 88 KT AND MAXIMUM
SFMR-OBSERVED SURFACE WINDS OF 75 KT.
THE NEW NHC
FORECAST IS LOWER THAN THE SHIPS/LGEM INTENSITY GUIDANCE BUT ABOUT
THE SAME AS THE PREVIOUS OFFICIAL FORECAST...INDICATING
INTENSIFICATION TO HURRICANE STRENGTH WITHIN 24 HOURS
;-)
Yes, I understand that but whether the TPC reports a cat one or borderline cat 2 storm - at this point is irrelevant. History has proven time and time again that the real suffering and loss of life from hurricanes similar to Tomas on this island will be as a result of mudslides in villages and valley flooding as a result of rainfall. At this point Tomas is still moving rather slow....thats the biggest problem.
Good morning to you. Yes, very sad. Nothing to do now but cross our fingers and put out good vibes to the multiverse...
I understand that too but this time people are not living in concrete homes where a measure of protection is available. There living in makeshift tents all over, not to mention houses that are barely standing. Of course flooding is the biggest danger but in this instance I think the wind will be a much bigger factor than would normally be in the past
METEOROLOGICAL SERVICE, JAMAICA
Division of the Office of the Prime Minister
Telephone: 876-924-8055/924-8404
FOR IMMEDIATE RELEASE: Friday, November 5, 2010 – 5:00 a.m.
BULLETIN No: 29
TROPICAL STORM WARNING REMAINS IN EFFECT
… TOMAS NOW A CATEGORY 1 HURRICANE
A TROPICAL STORM WARNING remains in effect for Jamaica while Tomas is upgraded to a hurricane while continuing to move away from the island. This means that tropical storm conditions, including possible sustained wind speeds of 34-63 knots or 63-117 km/h (39-73 mph) are expected, in this case within 3-6 hours.
At 4:00 a.m. the centre of Hurricane Tomas was located near Latitude 18.1 degrees North, Longitude 74.9 degrees West; about 150 km (90 miles) east of Morant Point, Jamaica or 280 km (175 miles) west of Port-au-Prince, Haiti.
Tomas is now moving towards the northeast near 15 km/h (9 mph) and this general motion, with a further increase in forward speed, is expected over the next couple of days. On the forecast track, the centre of Tomas will continue moving away from Jamaica and near southwestern Haiti this morning, before passing near extreme eastern Cuba later today.
Maximum sustained winds have increased to near 130 km/h (80 mph), with higher gusts, making Tomas a Category 1 hurricane on the Saffir-Simpson scale. Additional strengthening is possible today before Tomas again begins to weaken on Saturday. Hurricane force winds extend outward up to 30 km (18 miles) from the centre, and tropical storm force winds extend outward as far as 220 km (140 miles). Jamaica could still, therefore, come under the influence of tropical storm force winds over sections of eastern parishes this morning
Satellite imagery and radar reports indicate that the heavy showers and thunderstorms associated with Tomas continue to skirt the eastern tip of Jamaica; however, scattered showers are being detected over sections of central and western parishes. These will rapidly decrease as drier air moves into the area behind Hurricane Tomas.
Small craft operators are, however, reminded to remain in safe harbour until all warning messages have been lifted and wind and sea conditions have returned to normal.
The Meteorological Service continues to monitor the progress of this system and will issue the next Bulletin on Hurricane Tomas at 8:00 a.m. today.
Even across the eastern Bahamas the track will take Tomas over two of the less-inhabited islands, and if it verifies, over the least inhabited parts of those islands. Really, Providenciales is most likely to get the worst of it, with the eye passing just to its west.
In any case, we shall see what we shall see. Stay safe out there, pple, and prayers going up for Haiti, Cuba, and the SE Bahamas / TCI.....
This went from bad to very bad fo Hati.
Any loss of life is tragic. Hope this does not turn out to be catastrophic!
It's pouring here with gusty winds.
Baha
Looks that way to me also... busy day today.
CRS
Constant Spring north of Kingston.
It's raining here in Barbican, St. Andrew Jamaica...heavily overcast...water running down the roads...situation ripe for flash flooding.
it's raining a lot
(~ 29.18 inHg)
Actually IMO only, it looks like Tomas is nearing peak intensity and is in the process of moving NE at an increasing rate of speed. I dont think we will see anymore significant increase in intensity. Its already a big problem for those in the path. I think in the next 6 - 8 hours we will begin to see the trof begin to take its toll on the west side of Tomas as sheer becomes an increasing factor. Time will tell.........
Thanks!!
Link
11:34 AM GMT en Noviembre 05, 2010
I agree, that's a gloomy looking satellite image to wake up to. So far, it looks like the earthquake zone has gotten about 3 inches of rain, and the tip of the SW peninsula has received up to 6 inches (note 25mm = 1 inch, the scaling is off a factor of 2x on this image):
These rain amounts are probably only half of what they will wind up with. The earthquake zone will probably be at risk of heavy loss of life for rain amounts in excess of about 5 inches.
Jeff Masters
PrayersUP for Haiti & Jamaica
BE SAFE CRS
auch Baha - that pic of Tomas is frightening - I woke up ready to complain about our temps being 57 degree's brrrr -- going to check my attitude real quick - not right to even consider whining when I see this monster aim at the islands
The Haitians are still suffering from colonialism and deforestation (the French colonists being responsible for wiping out a good portion of the forests to export tropical wood)
A special candle will be lit today -- there's a lot of Mommies w/Babies and children with fear in their hearts and no safe place to go - praying for Divine Intervention
about 68 miles from the first dropsounde reading
NNE
Jeff what do you think this will peak out again at... it seems to be strengthening at a pretty good clip right now
Does that rain include the tail? How do you see that moisture moving -- right now it's almost lined up on Haiti, but perhaps it will trail eastward as well?
Transmitted: 5th day of the month at 11:23Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 301)
Storm Number & Year: 21L in 2010
Storm Name: Tomas (flight in the North Atlantic basin)
Mission Number: 18
Observation Number: 20
A. Time of Center Fix: 5th day of the month at 11:08:10Z
B. Center Fix Coordinates: 18°37'N 74°47'W (18.6167N 74.7833W)
B. Center Fix Location: 119 miles (192 km) to the SE (145°) from Santiago de Cuba, Cuba.
C. Minimum Height at Standard Level: 1,334m (4,377ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 63kts (~ 72.5mph)
E. Location of the Estimated Maximum Surface Wind: 13 nautical miles (15 statute miles) to the NW (324°) of center fix
F. Maximum Flight Level Wind Inbound: From 27° at 68kts (From the NNE at ~ 78.3mph)
G. Location of Maximum Flight Level Wind Inbound: 13 nautical miles (15 statute miles) to the NW (324°) of center fix
H. Minimum Sea Level Pressure: 988mb (29.18 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 14°C (57°F) at a pressure alt. of 1,521m (4,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 20°C (68°F) at a pressure alt. of 1,522m (4,993ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 18°C (64°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 0.5 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 88kts (~ 101.3mph) in the southwest quadrant at 8:00:30Z
Maximum Flight Level Wind Outbound: 81kts (~ 93.2mph) in the south quadrant at 11:13:40Z
Maximum Surface (likely estimated by SFMR) Wind Outbound: 74kts (~ 85.2mph) in the south quadrant at 11:13:20
Remarks Section - Additional Remarks...
HEAD OF SPIRAL BAND NOW IN S QUAD APPROX 15 NM FM CNTR
Viewing: 801 - 851
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