Prognostic Meteorological Discussion
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FXCA20 KWBC 111132
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
632 AM EST THU FEB 11 2016

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM FEBRUARY
11/06 UTC: STRONG TRADE WINDS CAP INVERSION CONTINUES TO ENVELOP
THE FORECAST AREA...WITH SHALLOW MOISTURE POOLING ACROSS THE
LEEWARD ISLES/EASTERN CARIBBEAN EARLY THIS MORNING. BRISK EASTERLY
TRADES DOMINATE THE LOW LEVELS...SO EXPECTING SOME OF THIS
MOISTURE TO EVENTUALLY ADVECT ACROSS THE FORECAST AREA EARLY ON
FRIDAY...TO FAVOR LIGHT CONVECTION AS THEY STREAM ACROSS THE
VIRGIN ISLES TO PUERTO RICO.

CAP INVERSION IS EXPECTED TO HOLD DURING THE NEXT 48-60 HRS...WITH
RAPID EROSION LATER ON SATURDAY/EARLY SUNDAY MORNING AS MID LEVEL
SHORT WAVE TROUGH ROUNDING LONG WAVE AXIS TO THE NORTH PULLS
ACROSS THE NORTHERN CARIBBEAN. ENVIRONMENTAL CONDITIONS ARE TO
THEN BECOME FAVORABLE FOR DEEP CONVECTION TO DEVELOP...WITH THE
GDI FORECAST SHOWING POTENTIAL FOR THUNDERSTORMS ACROSS WESTERN
AND INTERIOR PORTIONS OF PUERTO RICO ON SUNDAY AND MONDAY
AFTERNOON. AT LOW LEVELS A PREFRONTAL SHEAR LINE MOVES ACROSS THE
MONA PASSAGE TO WESTERN PUERTO RICO ON SUNDAY EVENING...WITH PWAT
FORECAST TO PEAK AROUND 30-35MM. THE INFLOW OF MID LEVEL VORTICITY
AND LOW THE INCREASE IN LOW LEVEL CONVERGENCE WILL LIKELY RESULT
IN MODERATE RAINFALL AMOUNTS.

ALTHOUGH LOW/MID LEVELS LOOK FAVORABLE AND CONDUCIVE TO
CONVECTION...THE UPPER LEVEL PATTERN DOES NOT LOOK AS FAVORABLE.
ON SUNDAY TO MONDAY THE MODELS SHOW A FINGER OF THE SUBTROPICAL
JET EXITING TO THE NORTH OF THE FORECAST AREA. IN RESPONSE...THE
GFS IS SHOWING WEAK UPPER CONVERGENCE. THIS MIGHT END UP DELAYING
ONSET OF THE CONVECTION TO THE AFTERNOON HOURS WHEN MAX HEATING IS
EXPECTED TO OVERCOME THE NEGATIVE INFLUENCE OF THE UPPER JET. THUS
FAR...THE GFS IS THE ONLY ONE SHOWING POTENTIAL FOR MODERATE
AMOUNTS...WHILE OTHER GLOBAL MODELS REMAIN SOMEWHAT RESTRAINT ON
THEIR DEVELOPMENT.

HUNTE...BMS (BARBADOS)
DAVISON/GALVEZ...WPC (USA)
$$




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