Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 12:16 PM GMT on September 30, 2013
A low pressure system (Invest 97L) over the Central Caribbean is generating heavy rains from Jamaica to the coast of Panama, and is moving northwest at about 8 mph. Satellite loops show 97L has a modest area of disorganized heavy thunderstorms. The broad area of spin 97L had on Sunday is less apparent today. Dry air covers the Northwest Caribbean, and this dry air is slowing development. Ocean temperatures are a very warm 29°C (84°F), and wind shear has fallen since Sunday, and is now a moderate 10 - 20 knots.
Figure 1. Latest satellite image of Invest 97L.
Forecast for 97L
Marginally favorable conditions for development are expected for the next five days, according to the latest SHIPS model forecast, with moderate levels of wind shear (10 - 20 knots), but an atmosphere that will grow drier as 97L approaches the Northwest Caribbean and Southeast Gulf of Mexico. None of the reliable computer forecast models develop 97L into a tropical depression over the next five days. These models (the GFS, ECMWF, and UKMET) predict a northwesterly track for 97L over the next three days, bringing the center into the Yucatan Channel between Mexico's Yucatan Peninsula and Western Cuba by Thursday. On this path, 97L will bring heavy rains of 2 - 4" to Jamaica and Southwest Haiti on Monday, to the Cayman Islands and Central and Eastern Cuba on Tuesday and Wednesday, and to Western Cuba and Mexico's Yucatan Peninsula on Wednesday and Thursday. It is uncertain if 97L will then turn northeast and affect Florida late in the week, or stay in the Central Gulf of Mexico and head north into Louisiana. In their 8 am EDT Monday Tropical Weather Outlook, NHC gave 97L 2-day odds of development of 10%, and 5-day odds of 30%.
Figure 1. Latest satellite image of TD 11.
Little change to Tropical Depression 11 in the Central Atlantic
Tropical Depression Eleven continues to wander slowly across the Central Atlantic, far from land. Wind shear from an upper-level just northwest of TD 11 is currently keeping the storm disorganized, with just a small area of heavy thunderstorms displaced from the center of circulation. However, the storm is more organized than on Sunday, and just a small reduction in shear should allow TD 11 to intensify into Tropical Storm Jerry. TD 11 is not a threat to any land areas.
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