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Noel over water, headed north towards the Bahamas

By: Dr. Jeff Masters, 1:50 PM GMT on October 31, 2007

Deadly Tropical Storm Noel has popped off the coast of Cuba and is headed north, according to the latest hurricane hunter data from 8:49am EDT this morning. The hurricane hunter data put Noel's center at 22.7 north, which is about 100 miles north of the coast of Cuba. Part of this northward motion was probably a relocation of the center underneath an impressive blow-up of thunderstorm activity visible on the latest satellite loops. These thunderstorms are generating rains of up to 1/2 inch per hour. Top winds found by the Hurricane Hunters were 40 mph, but these winds are expected to increase today as Noel re-organizes after its long stay over Cuba.

The rains continue to fall over hard-hit Hispaniola, where the death toll is at least 43, with many more missing. Most of the deaths were in the southern part of the Dominican Republic just west of the capital of Santo Domingo, where up to 19 inches of rain has have fallen. An additional 1-3 inches of rain fell in the 24 hours ending at 2am EDT today (Figure 1), and an additional 1-4 inches is likely by Thursday morning. The rains should taper off Thursday as Noel pulls away from the island. Noel is the deadliest tropical cyclone to affect the Dominican Republic since Hurricane Georges hit Hispaniola in 1998, killing 380 Dominicans and causing over $1 billion in damage to the county.

Cuba and the Bahamas
Rains have also been heavy over the Bahamas, where some islands have received six inches of rain. Nearby ocean areas have gotten up to ten inches. Cuba has fared better, with maximum rainfall amounts less than six inches. The rains will continue into Thursday then taper off as Noel pulls away to the north.

Figure 1. Satellite estimated rainfall for the 24 hours ending at 2am EDT Wednesday, 10/31/07. Rainfall is in millimeters, and 1" = about 25 mm, so orange colors are 10" of rain. Noel dumped as much as 10 inches of rain over ocean areas in the Central Bahamas, and an additional three inches over hard-hit regions of the Dominican Republic that had already received 10-17 inches earlier this week. Image credit: Navy Research Lab, Monterey.

Links to follow for Noel
Satellite loop
Camaguey, Cuba radar.
Nassau, Bahamas current weather
Google Maps interface, zoomed in on Nassau, Bahamas

The forecast
Visible satellite from this morning suggests that the surface circulation and mid-level circulation are closer together, which will aid in intensification of Noel today as the storm pushes off the coast. Wind shear is 10-20 knots, which will allow some modest strengthening. By Thursday, wind shear is expected to increase to 25 knots, halting any intensification as a tropical storm. The latest computer model runs from 00Z and 06Z this morning all take Noel through the Bahamas, over or near Andros Island and Nassau. The SHIPS and GFDL intensity models forecast that Noel will have 60 mph top winds by Thursday afternoon, when the storm should be leaving the Bahamas. The HWRF model does not intensify Noel. I expect some intensification, given the better vertical alignment of the surface and mid-level centers of Noel, respectable 995 mb pressure just measured by the Hurricane Hunters, and the improved satellite appearance of the storm. A storm with 50-60 mph top winds on Thursday afternoon is a reasonable forecast. None of the models take Noel over South Florida, and the region most likely to suffer wind damage from Noel will be the Canadian Maritime provinces of Nova Scotia and Newfoundland. Noel is expected to transition to, or be absorbed by, an extratropical storm on Thursday. This extratropical storm will then intensify, potentially bringing sustained winds of 55-75 mph to the Canadian Maritimes on Saturday night and Sunday morning.

Impact on Florida
There is no change to the forecast for Florida. Noel will pass east of the state as a weak but strengthening tropical storm. Winds will probably blow 20-30 mph with gusts to 40 mph along the coast of Florida on Thursday morning, when Noel makes its closest approach. Florida will be on the dry side of Noel, thanks to upper level winds from the west that will be creating about 15-25 knots of wind shear over the storm. Expect occasional heavy rain showers with rain amounts totaling 1-3 inches if you live along the Southeast Florida coast. Most of Noel's heavy rains should stay offshore. The main hazard from Noel will be beach erosion, thanks to the 10-foot seas expected to pound area beaches.

I'll have an update this afternoon.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.