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FXCA20 KWBC 091249
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
749 AM EST THU FEB 09 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM FEB
09/12UTC: A SURFACE HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL
KEEP EAST-NORTHEAST WINDS AT AROUND 17-22KT ACROSS THE LOCAL AREA
TODAY AS THE HIGH PRESSURE MOVES EAST. THE LOCAL WINDS WILL BECOME
EASTERLY FROM FRIDAY ONWARD...WITH SPEEDS AT AROUND 15-20 KNOTS
AND GUSTY...THOUGH FRIDAY INTO EARLY SATURDAY WOULD BE ON THE
HIGHER END OF THAT RANGE. A FRONTAL BOUNDARY IS STILL PRESENT TO
THE NORTH OF THE LOCAL AREA AT AROUND LATITUDE 23N...BUT IT IS
WEAKENING AND EXPECTED TO REMAIN NORTH OF THE LOCAL
AREA...DISSIPATING ON SATURDAY INTO SUNDAY. A MID LEVEL HIGH
PRESSURE IS LOCATED OVER THE BAHAMAS AND MOVING EAST TO THE NORTH
OF THE GREATER ANTILLES...WHILE A MID LEVEL TROUGH IS JUST SOUTH
AND EAST OF PUERTO RICO...ALSO MOVING EAST SLOWLY. THE LOCATION OF
THE MID LEVEL HIGH PRESSURE AND TROUGH IS STILL NOT IN THE BEST
LOCATION TO SUPPORT DEEP CONVECTION OVER THE NORTHEASTERN
CARIBBEAN...BUT IT DOES HELP SUPPORT A MORE WIDESPREAD AREA OF
RAIN SOUTH OF PR/USVI...ACROSS THE CARIBBEAN WATERS AND LESSER
ANTILLES. A TROUGH AT 250MB OVER HISPANIOLA AND PR IS MOVING
EAST...GRADUALLY CAUSING SOME SUBSIDENCE OVER THE LOCAL AREA AND
MAKING IT MORE DIFFICULT FOR AFTERNOON CONVECTION TO AFFECT
WESTERN PR TODAY. GIVEN THIS PATTERN...TRADE WIND SHOWERS WOULD BE
THE MAIN REASON FOR RAINFALL ACCUMULATION OVER PR/USVI
TODAY...GENERALLY AFFECTING NORTH AND EAST PR...AS WELL AS THE
USVI. THAT BEING SAID...TRADE WIND SHOWERS WILL AFFECT THESE AREAS
EACH DAY IN THE NEXT 5 DAYS...THOUGH SOME CONVECTION ACROSS W/NW
PR MAY BE POSSIBLE ON SATURDAY ONWARD.
THE AVAILABLE MOISTURE IS SLIGHTLY BELOW NORMAL THIS MORNING...BUT
WILL INCREASE TO NEAR NORMAL VALUES...WITH PRECIPITABLE WATER
VALUES NEAR 1.4 INCHES EXPECTED. NORTH AND EASTERN PR HAS ALREADY
OBSERVED ABOUT 0.10 TO 0.3 INCHES OF RAIN THIS MORNING...AND
ADDITIONAL MORNING SHOWERS ARE EXPECTED OVER THE AREA...WITH MAX
AMOUNTS OF OVER A HALF AN INCH. THE USVI ARE EXPECTED TO OBSERVE
MORE MODEST AMOUNTS WITH MAX AMOUNTS NEAR A TENTH OF AN INCH OR
LESS. FROM FRIDAY ONWARD...THE PRECIPITABLE WATER WILL BE UP AND
DOWN FROM NEAR NORMAL TO BELOW NORMAL...AS PATCHES OF MOISTURE
MOVE THROUGH...CAUSING THE PRECIPITABLE WATER TO BE GENERALLY
BETWEEN 1.4 AND 1.1 INCHES OR SO. THE TRADE WIND INVERSION WILL BE
LIMITED FOR THE NEXT FEW DAYS...AND THERE WILL BE A CHANCE OF RAIN
EACH DAY...ALTHOUGH MAINLY IN THE WAY OF TRADE WIND
SHOWERS...CAUSING UP TO A HALF AN INCH OR SO OF AN INCH OF RAIN
EACH DAY OVER THE NEXT 5 DAY PERIOD...THOUGH ISOLATED AREAS COULD
OBSERVE HIGHER AMOUNTS. AT THIS TIME...TODAY APPEARS TO BE THE
TIME PERIOD WITH HIGHEST AMOUNTS OF RAIN UNDER THE TRADE WIND
SHOWER PATTERN. BUT SATURDAY INTO NEXT WEEK COULD HAVE AFTERNOON
CONVECTION CAUSING AROUND A HALF AN INCH OF RAIN ACROSS W/NW PR
DUE TO THE COMBINATION OF AVAILABLE MOISTURE AND SEA BREEZE
CONVERGENCE.
ALAMO/ACOSTA...WPC (USA)
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