367
FXCA20 KWBC 201248
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
748 AM EST MON NOV 20 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI NOV 20/12UTC:
A SFC LOW PRESSURE NEAR 31N/60W HAS AN ASSOCIATED COLD FRONT
EXTENDING TO ITS SW INTO THE BAHAMAS. THERE IS ALSO A SFC TROUGH
OVER WESTERN HISPANIOLA INTO THE CARIBBEAN. SATELLITE IMAGERY
INDICATES SHOWERS AND THUNDERSTORMS ALONG THE FRONT AND TROUGH
FROM NORTH OF THE CENTRAL BAHAMAS INTO THE SOUTHWESTERN CARIBBEAN.
AS THE SFC LOW OVER THE ATLANTIC MOVES EAST OVER THE NEXT FEW
DAYS...THE COLD FRONT MOVES EAST AS WELL...GETTING VERY CLOSE TO
NORTHERN PR. THIS WILL CAUSE THE AVAILABLE MOISTURE TO INCREASE
TODAY INTO THE ABOVE NORMAL LEVELS...BUT RAPIDLY DECREASE ON
TUESDAY...REMAINING BELOW NORMAL FOR THE REST OF THE WORKWEEK.
THEREFORE...THE SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE
VERY CLOSE OR OVER WESTERN PR TODAY...AND THEN POSSIBLY AFFECTING
EASTERN AND NORTHERN PR AND THE USVI INTO TUESDAY MORNING AS THE
FRONTAL BOUNDARY MOVES EAST AND THE WINDS START TO SHIFT FROM A
SOUTHERLY DIRECTION TODAY...TO A NORTHERLY DIRECTION BY TUESDAY.
WINDS WILL BE NORTHEASTERLY ON WEDNESDAY...THEN EASTERLY FOR THE
LATTER PART OF THE WEEK. IN THE MID AND UPPER LEVELS...SOME
TROUGHINESS IS EXPECTED JUST NORTH OF THE LOCAL ISLANDS TODAY.
HOWEVER...A HIGH PRESSURES IN THE MID AND UPPER LEVELS OVER THE
WESTERN CARIBBEAN WILL MOVE EAST AND PROMOTE STABILITY OVER
PR/USVI STARTING VERY EARLY WEDNESDAY ONWARD. THIS MAY CAUSE A CAP
FOR THE MIDDLE TO THE LATTER PART OF THE WEEK...AND THUS MAINLY
SHALLOW AND ADVECTIVE SHOWER ACTIVITY WOULD BE EXPECTED FROM
WEDNESDAY ONWARD...AFFECTING MAINLY THE USVI AND EASTERN PR.
THE 5-DAY TOTAL RAINFALL FORECAST IS TO REACH 1 - 1.5 INCHES
ACROSS SMALL SECTIONS OF NORTHWESTERN PR AND NORTHEASTERN PR. THE
USVI COULD OBSERVE UP TO AN INCH OF RAIN OVER THE 5-DAY PERIOD.
THE DAY WITH HIGHEST ACCUMULATIONS FOR NORTHWESTERN PR IS EXPECTED
TO BE TODAY...WHILE TUESDAY WOULD BE THE RAINIEST DAY FOR THE
USVI.
ALAMO...WPC (USA)
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