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FXCA20 KWBC 081250
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
750 AM EST WED FEB 08 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM FEB
08/12UTC: A SURFACE HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL
KEEP EAST-NORTHEAST WINDS ACROSS THE LOCAL AREA TODAY AND ON
THURSDAY AS THE HIGH PRESSURE MOVES EAST. THE LOCAL WINDS WILL
BECOME MORE EASTERLY FROM FRIDAY ONWARD. WIND SPEEDS WILL BE AT
AROUND 20 KNOTS AND GUSTY FOR THE NEXT SEVERAL DAYS...AT LEAST
THROUGH THE END OF THE WORKWEEK. A FRONTAL BOUNDARY IS PRESENT TO
THE NORTH OF THE LOCAL AREA AT AROUND LATITUDE 24N...BUT IT IS
EXPECTED TO REMAIN NORTH OF THE LOCAL AREA WHILE IT WEAKENS OVER
THE COURSE OF THE NEXT SEVERAL DAYS. A MID LEVEL TROUGH HAS AN
AXIS TO THE SOUTH AND EAST OF THE LOCAL ISLANDS AND 500MB TEMPS
REMAIN BELOW NORMAL...STILL EXPECTED AT -10 TO -11 FOR THE NEXT
SEVERAL DAYS. THE POSITIONING OF THE MID LEVEL TROUGH IS NOT IN
THE BEST LOCATION TO SUPPORT DEEP CONVECTION OVER THE LOCAL
ISLANDS. A TROUGH AT 250MB OVER HISPANIOLA WILL SLOWLY MOVE EAST
TODAY AND ON THURSDAY...WHICH COULD CAUSE AN INCREASE IN
INSTABILITY OVER PR/VI...BUT THE STRONGEST DIVERGENCE AND UPPER
LEVEL WINDS WILL BE TO THE EAST OF THE ISLANDS. GIVEN THIS
PATTERN...TRADE WIND SHOWERS AFFECTING THE USVI AS WELL AS NORTH
AND EAST PR IN THE MORNINGS AND OVERNIGHT HOURS ARE EXPECTED EACH
DAY. AFTERNOON CONVECTION ACROSS SW-PR IS FAVORED TODAY AND
SLIGHTLY LESS SO ON THURSDAY AS THE UPPER TROUGH IS A BIT MORE
SUPPORTIVE OF AFTERNOON CONVECTION THAN IT IS ON THURSDAY. BY
FRIDAY...THE UPPER TROUGH WOULD BE TO THE EAST OF THE
ISLANDS...CAUSING SOME SUBSIDENCE OVER THE LOCAL ISLANDS.
TODAY...THE AVAILABLE MOISTURE IS IN THE UPPER END OF NORMAL FOR
THE TIME OF YEAR...NEAR 1.5 INCHES OF PRECIPITABLE WATER...BUT IS
EXPECTED TO GRADUALLY DECREASE AS THE DAY PROGRESSES. SHOWERS
COULD DEVELOP ACROSS THE SOUTHWESTERN QUADRANT OF PR DUE TO THE
COMBINATION OF THE AVAILABLE MOISTURE...DIURNAL HEATING...AND SEA
BREEZE CONVERGENCE WITH SOME PROXIMITY TO THE DIVERGENT SIDE TO
THE UPPER TROUGH. EVEN THOUGH THE GDI DOES NOT SUGGEST A HIGH
CHANCE OF THUNDERSTORMS...VERY ISOLATED THUNDERSTORMS COULD BE
POSSIBLE IN THE AFTERNOON OVER SOUTHWESTERN PR AS WELL AS OVER THE
LOCAL WATERS IN THE AFTERNOON. NORTH AND EASTERN PR HAS ALREADY
OBSERVED ABOUT 0.25 TO 0.4 INCHES OF RAIN THIS MORNING...AND
ADDITIONAL MORNING SHOWERS ARE EXPECTED OVER THE AREA...WITH MAX
AMOUNTS OF NEAR THREE QUARTERS OF AN INCH. THE USVI ARE EXPECTED
TO OBSERVE MORE MODEST AMOUNTS WITH MAX NEAR A QUARTER OF AN INCH
IN THE NORTHERN USVI AND UNDER A TENTH OF RAIN AT SAINT CROIX.
FROM THURSDAY 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 FOR THE NEXT SEVERAL DAYS. 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 NEAR THREE QUARTERS OF AN INCH OF RAIN
TOTAL ON THURSDAY AND PERHAPS LESSER AMOUNTS ON FRIDAY
ONWARD...WITH MAX AMOUNTS CLOSER TO A QUARTER OF AN INCH...THOUGH
ISOLATED AREAS COULD OBSERVE HIGHER AMOUNTS. AT THIS TIME...TODAY
AND THURSDAY APPEAR TO BE THE TIME PERIOD WITH HIGHEST AMOUNTS OF
RAIN.
ALAMO/ACOSTA...WPC (USA)
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