209
FXCA20 KWBC 221252
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
752 AM EST WED NOV 22 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI NOV 22/12UTC:
NORTHEASTERLY WINDS WILL GRADUALLY BECOME EASTERLY BY LATE
TONIGHT...THEN EAST SOUTHEASTERLY BY THURSDAY. THE AVAILABLE
MOISTURE WILL BOTTOM OUT TODAY WITH PRECIPITABLE WATER NEAR 1.25
INCHES...BUT AN AREA OF HIGHER MOISTURE WILL LINGER NEAR THE LOCAL
ISLANDS OVER THE NEXT FEW DAYS...CAUSING THE PRECIPITABLE WATER TO
INCREASE TO NORMAL LEVELS WITH VALUES BETWEEN 1.5 AND 1.75 INCHES
ON THURSDAY AND FRIDAY. PRECIPITABLE WATER WILL INCREASE EVEN MORE
ON SATURDAY...WITH VALUES NEAR OR OVER 2 INCHES...THEN DECREASING
TO BELOW NORMAL SUNDAY AS THE LINE OF MOISTURE MOVES WEST OF THE
LOCAL ISLANDS. THIS IS DUE TO A SFC LOW PRESSURE OVER THE CENTRAL
TROPICAL ATLANTIC THAT IS MOVING EAST WHILE A SFC HIGH PRESSURE
WILL GRADUALLY MOVE INTO THE CENTRAL TROPICAL ATLANTIC...CAUSING
THE SHIFT IN WIND DIRECTION AND PUSHING THE LINE OF MOISTURE
WEST...OVER PR/USVI BY SATURDAY AND BRINGING THE DRIER AIR ON
SUNDAY.
THIS GENERAL PATTERN WILL CAUSE SOME SHOWER ACTIVITY TO AFFECT
NORTHERN AND EASTERN PR AS WELL AS THE USVI THROUGH THE END OF THE
WORKWEEK. HOWEVER...GIVEN THE NE WIND COMPONENT
TODAY...SOUTHWESTERN PR COULD OBSERVE SOME RAINFALL IN THE
AFTERNOON. THEN AN E-SE WIND DIRECTION EXPECTED ON THURSDAY WITH
THE MOISTURE ADVECTION EXPECTED...COULD CAUSE PORTIONS OF
NORTHWESTERN PR TO OBSERVE RAINFALL ON THURSDAY AFTERNOON. THE
AMOUNTS OF RAIN EXPECTED TODAY AND THURSDAY COULD BE AS MUCH AS A
HALF AN INCH OR SLIGHTLY MORE...THOUGH THE HI-RES MODEL GUIDANCE
SUGGESTS ISOLATED AREAS OF EVEN HIGHER AMOUNTS. UNDER A HALF AN
INCH OF RAIN IS FORECAST ON FRIDAY ONWARD...THOUGH THE GFS MODEL
WAS SUGGESTING SIGNIFICANT RAIN...NEAR AN INCH OVER EASTERN PR FOR
SATURDAY...THOUGH THE ECMWF HAD MUCH LOWER AMOUNTS IN ITS FORECAST
SOLUTION.
IN THE MID AND UPPER LEVELS...HIGH PRESSURES IN THE MID AND UPPER
LEVELS CENTERED OVER THE CENTRAL TO WESTERN CARIBBEAN WILL PROMOTE
STABILITY OVER PR/USVI FROM TODAY ONWARD. THIS MAY CAUSE A CAP
THROUGH THE REST OF THE WEEK...AND THUS MAINLY SHALLOW CONVECTION
AND ADVECTIVE SHOWER ACTIVITY WOULD BE EXPECTED OVER THE NEXT
SEVERAL DAYS. THE 5-DAY TOTAL RAINFALL FORECAST IS TO REACH 1 -
1.25 INCHES ACROSS WESTERN TO NORTHWESTERN PR...AND UP TO NEARLY 2
INCHES ACROSS NORTHEASTERN PR. THE USVI ALONG WITH VIEQUES AND
CULEBRA HAS A 5-DAY TOTAL RAINFALL FORECAST OF 0.5 TO JUST OVER 1
INCH. THAT BEING SAID...ISOLATED HIGHER AMOUNTS ARE POSSIBLE.
ALAMO...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page