A broad region of low pressure in the Central Caribbean south of Haiti and the Dominican Republic, (Invest 97L), is moving west at 10 - 15 mph. Heavy thunderstorm activity has decreased since yesterday, and is disorganized. The storm is surrounded by a large region of dry air, and this dry air is the main impediment to development. Wind shear is a low 5 - 10 knots, and is expected to remain low through Thursday. None of the reliable models are predicting that 97L will develop, and NHC gave 97L just a 10% chance of developing into a tropical depression by Friday, in their 8 am EDT Tropical Weather Outlook. NHC is no longer interested enough in 97L to generate computer model forecasts of its track. Heavy rains from 97L should reach Jamaica on Thursday, and the Cayman Islands by early Friday morning.

Jeff Masters

There is another area to watch for a new development over the next few days. A tropical wave is crossing the eastern Caribbean with the wave axis along 69 west, south of 17 north, slowly edging westward. There is a large but spotty and disorganized area of showers and thunderstorms with this wave over the central and eastern part of the Caribbean. Upper-level winds in this area are marginally favorable for development, though there is some northerly shear along the wave axis south of Puerto Rico. Waters are very warm over the Caribbean Sea ahead of this wave. The odds of further development over the next day or so are long, but there is a decent chance that this develops further toward the end of the week.