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 , 7:55 PM GMT on October 06, 2005
Tammy is still generating heavy rains of up to 1/2 inch per hour in North Carolina and South Carolina, but this storm has done its worst and no longer has any spin. A portion of the storm may pop back out over the Gulf of Mexico Friday, but no tropical storm development is expected, due to wind shear from an upper level low in the Gulf. 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. Rainfall amounts from Tammy will generally be in the 1 - 3 inch range along the coast, and 3 - 6 inches in the Appalachians, creating some localized flooding problems.
The large area of thunderstorms that broke off from Stan yesterday is now a 1004 mb low pressure system just north of the western tip of Cuba. This system has just a small area of deep convection to the southeast of the center. Upper-level outflow is apparent to the southeast, but nowhere else. Wind shear of about 10 knots from westerly upper-level winds is pushing the convection away from the center. 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 is not likely, given the system's current disorganized state. This system no longer looks like a big rain-producer for Florida, and some of the flood watches posted for the state may be dropped later today if the system does not gain any more strength. Stan Jr. will continue to the northeast and dump another 1 -2 inches of rain on the areas already affected by Tropical Storm Tammy.
Figure 1. Model tracks for Stan Jr.--the tropical disturbance off of the Yucatan.
The death toll from Hurricane Stan still stands at 162, including 62 deaths in El Salvador, 79 in Guatemala, and 21 in Nicaragua, Mexico, and Honduras. The remnants of Stan are no longer dumping heavy rain on the area, and only scattered thunderstorms are expected in the disaster area the next five days.
Figure 2. 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 Puerto Vallarta, and winds of 40 - 50 mph have been observed in association with this system. However, no surface circulation has been observed yet, and this is not quite yet a tropical storm. This system will track northwestward over the next few days and threaten Baja California and the mainland Mexican coast.
A tropical disturbance near 9N 43W, about 1100 miles east of the Lesser Antilles Islands, it looking more ragged this afternoon. It is not expected to become a tropical depression today. 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.
Figure 3. Model tracks for the mid-Atlantic disturbance.
Elsewhere in the tropics
Plenty of low pressure and light wind shear continue to characterize the rest of the tropics, and we need to keep a watchful eye for new suspect areas that may crop up.
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