Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 1:42 PM GMT on October 06, 2005
Tropical Storm Tammy came ashore at 7 pm EDT last night near the Florida Georgia border with sustained winds of 50 mph, a storm surge of 1 - 3 feet, and torrential rains. Rainfall amounts across southeast Georgia and coastal sections of
southeast South Carolina have been in the 2 to 7 inch range, with 2 inches or less across interior South Carolina. The highest rainfall totals between 4 and 7 inches have occurred between Folly Beach and Darien. Additional rainfall amounts of 2 to 4 inches are possible today. While numerous instances of urban and small stream flooding have been observed, no major flooding damage has been reported from Tammy.
Figure 1. Estimated rainfall from the Jacksonville radar.
Tammy is being drawn westward across Georgia by an upper level low over the northern Gulf of Mexico, and is expected to dissipate tonight. A cold front is expected to arrive over the East Coast Friday,pulling the remains of Tammy northward up the front, drenching the entire East Coast.
The large area of thunderstorms that broke off from Stan yesterday is now a 1005 mb low pressure system over the Yucatan Channel between Cuba and the Yucatan Peninsula. Satellite imagery shows a very disorganized system with the main cloudiness well east and north of the center. Not much upper-level outflow is apparent. Wind shear of about 10 knots from westerly upper-level winds is pushing the convection away from the center, towards the east. Observations from Cuban radar confirm that this a poorly organized system with a few bands of heavy showers over western Cuba.
This system is expected to push northward the next two days, spreading heavy rain and high winds over western Cuba, the Florida Keys, and the Florida Peninsula. Development into a tropical depression today is not likely, given the system's current disorganized state. Florida can expect conditions similar to those a tropical depression or weak tropical storm would bring, however, with rain amounts of 3 - 5 inches and high winds. The system will continue to the northeast and drench the areas already dumped on by Tropical Storm Tammy, and the entire East Coast will need to be concerned about flooding problems from this one-two punch.
Figure 2. BAMM and GFDL model tracks for Stan Jr.--the tropical disturbance off of the Yucatan.
The death toll from Hurricane Stan now stands at 162, including 62 deaths in El Salvador, 79 in Guatemala, and 21 in Nicaragua, Mexico, and Honduras. Unconfirmed reports from remote villages in Guatemala indicate that hundred more may be dead. Extensive deforestation in the high mountains where Stan's heavy rains fell contributed significantly to this disaster; the lack of tree cover allowed floodwaters to rampage down the mountainsides unchecked. The remnants of Stan will continue to pour heavy rains on this area today, but should ease off Friday.
Stan, who barely made it to Category 1 strength for a few hours, will likely have his name retired, thanks to this unfolding disaster. This would make the Hurricane Season of 2005 the first season to have five names retired (1955, 1995, and 2004 all had four storm names retired).
Figure 3. Stan's observed rainfall from the NASA TRMM satellite. Rainfall amounts as high as 400 mm (16 inches) were observed along the coast.
The remants of Stan have formed a large area of intense convection near the Mexican coast by Acapulco amd Puerto Vallarta, and appear likely to spin up into a new tropical depression today. This storm will track northwestward and threaten Baja and much of the Mexican Pacific coast.
A tropical disturbance near 8N 43W, about 1200 miles east of the Lesser Antilles Islands, has developed a low level circulation, impressive deep convection, and the beginnings of an upper-level outflow channel to the north. About 10 knots of shear from strong westerly winds is affecting the disturbance, but models indicate that this shear may decrease over the next day or two. The disturbance is moving west at 15 - 20 mph. A more northwestery motion is likely by Saturday, thanks to the steering influence of a large upper-level low pressure system at 25N 60W.
The disturbance is pretty far south for development to occur, and I don't expect a tropical depression here today. Development is more likely Friday or Saturday, when the disturbance will be further from the equator and can take advantage of the Earth's spin to help it develop.
Figure 4. BAMM and GFDL model tracks for the mid-Atlantic disturbance.
Elsewhere in the tropics
Conditions are expected to be unusually conducive for tropical storm formation throughout the Atlantic for the next 10 days, and it is quite likely we'll make it to the end of the alphabet by mid-October. When that happens, we go Greek--Alpha, Beta, and hopefully not much further into the Greek Alphabet!
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