CARIBBEAN SEA...
BROAD UPPER LOW IN THE W CARIBBEAN IS CENTERED JUST W OF JAMAICA
NEAR 18N81W COVERING THE AREA N OF 15N W OF 75W TO THE YUCATAN
PENINSULA. THIS IS GENERATING ISOLATED SHOWERS N OF 19N FROM THE
WINDWARD PASSAGE TO OVER THE YUCATAN CHANNEL. BROAD UPPER RIDGE
EXTENDS ACROSS THE S CARIBBEAN FROM COSTA RICA/NICARAGUA ALONG
14N70W TO ACROSS THE LESSER ANTILLES NEAR 16N61W INTO THE W
TROPICAL ATLC. THIS IS PROVIDING ENOUGH DIFFLUENCE OVER S AND E
CARIBBEAN TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S
OF 16N W OF 67W WITH CLUSTERS OF SCATTERED MODERATE/STRONG
CONVECTION FROM 11N-16N BETWEEN 77W-84W. MODERATE TRADEWINDS ARE
ACROSS THE AREA.
http://www.ssd.noaa.gov/goes/east/watl/avn-l.jpg