[Arubalisa]

Disturbance 94L approaching the Lesser Antilles
Heavy thunderstorms associated with a tropical wave (94L) near 11N, 57W, about 200 miles east of the Lesser Antilles Islands, have steadily grown more concentrated over the past day. This morning's QuikSCAT pass showed no closed circulation, but did show a pronounced wind shift associated with the disturbance. Top sustained winds were about 30 mph. Visible satellite loops show no evidence of rotation, and the area covered by heavy thunderstorms is relatively modest. The storm has moistened its environment considerably, and dry air should be less and less of a problem for the storm over the next few days. Wind shear has fallen to a modest 10 knots over 94L and is expected to remain in the low range, 5-10 knots, for the next four days. NHC is giving this system a medium (20%-50% chance) of developing into a tropical depression by Monday morning.

The forecast for 94L
The GFDL model, which with yesterday's run was developing 94L into a powerful hurricane that threatens Jamaica, is no longer developing the storm. The ECMWF, NOGAPS, and Canadian model all develop 94L. They foresee the system will enter the eastern Caribbean Sunday, jog northwest and affect the Dominican Republic on Tuesday, then develop into a tropical depression by Thursday near the Dominican Republic or eastern Bahama Islands. The wind shear forecast for the Caribbean calls for very low values of wind shear below 5 knots for most of the coming week (Figure 2). Residents of the Lesser Antilles can expect heavy rain and 40 mph wind gusts from 94L when it blows through Saturday night through Sunday. Residents of the Dominican Republic, Haiti, and Jamaica should keep a careful eye on this potentially dangerous disturbance.