Jul 31, 2016

Atlantic Tropics

Two tropical disturbances have been working their way across the Atlantic Ocean during the past few days. One out over the far Eastern Atlantic, a couple of hundred miles to the west-southwest of the Cape Verde Islands remains poorly organized and is not expected to develop much as it continues its westward trek over the Atlantic, moving into a hostile environment of strong wind shear and dry air.

On the other hand, a strong tropical disturbance dubbed 97L, is zipping quickly west across the Caribbean Sea.
Satellite imagery of tropical disturbance 97L
While surface data indicates no "closed" circulation  center (of low pressure) with this feature at the present time, the associated area of convection is increasing in both coverage and strength. The fast forward motion of the system is currently a detriment to its development but the forward speed is expected to decrease over the next 48 hours.

As 97L moves into the Western Caribbean Sea (west of 72°W longitude) by late Tuesday (2 Aug 2016), it will begin to move into an area that from a statistical climatology perspective is very favorable for tropical systems to intensify.

Also from a climatology perspective, systems that enter the Caribbean Sea near or south of approximately 15° N latitude on a general westerly heading (both of which 97L has done), tend to "keep" this heading. Forecast model tracks support the "climatology motion", with  97L likely passing close to or more likely to the south of Jamaica.

Forecast model tracks for 97L
As for the models that predict intensity, most show 97L to become a depression once it moves west of longitude 72° W, a few indicate it becoming a tropical storm and a couple have it intensifying into a hurricane.

Very warm Sea Surface Temperatures (SSTs) of near 80° F or warmer and the forecast of favorable

environmental conditions: very moist air and little wind shear would likely favor intensification of this system into a tropical storm. If this were to happen it would be christened with the name EARL.