TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
605 AM EDT TUE APR 16 2024

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI APR 16/12UTC:
AN UPPER TROUGH CONTINUES TO DEEPEN WHILE EXTENDING OFF THE EAST
COAST OF THE USA INTO THE WINDWARD PASSAVE/SOUTHEAST CUBA. THIS IS
INTERACTING WITH A MOIST PLUME THAT HAS REACHED PRECIPITABLE WATER
VALUES OVER 50MM...TRIGGERING SCATTERED DEEP CONVECTION NORTH OF
PUERTO RICO. AS THIS IS FAVORING A LOWERING OF SURFACE
PRESSURES...TRADE WINDS ACROSS PUERTO RICO AND THE VI ARE FROM THE
EAST SOUTHEAST. SATELLITE IMAGERY IS SHOWING MOST OF THE STRONGEST
CONVECTION FLARING UP WELL TO THE NORTH OF THE ISLANDS...ALTHOUGH
A FEW MORNING CONVECTIVE CELLS ARE EVIDENT IN PORTIONG OF THE VI.

ON TUESDAY...EXPECT THE CURRENT WEATHER PATTERN TO CONTINUE. THIS
IMPLIES THE STRONGEST CONVECTION REMAINING WELL TO THE NORTH OF
THE ISLANDS...WHILE SOUTHEASTERLY TRADES ENHANCE LOW-LEVEL SHEAR
AND FAVOR AFTERNOON DEVELOPMENT IN FAR NORTH-CENTRAL PUERTO
RICO...WHERE EXPECT MAXIMA NEAR 1 INCH. AFTER THIS PERIOD...THE
UPPER TROUGH IS FORECAST TO ROLL EASTWARD GRADUALLY WHILE BECOMING
BROADER. THIS WILL CONTINUE TO FAVOR SUFFICIENT INSTABILITY TO
FAVOR VERTICAL DEVELOPMENT THROUGH THE FORECAST CYCLE.
HOWEVER...AS PRECIPITABLE WATER AMOUNTS DECREASE
SIGNIFICANTLY...EXPECT THE COVERAGE OF PRECIPITATION TO DECREASE.
THE TRADES ARE EXPECTED TO BECOME WEAK AND ACQUIRE A NORTHEASTERLY
COMPONENT ON WEDNESDAY...FORECAST TO PERSIST INTO THE WEEKEND.
THIS WILL FAVOR AFTERNOON CONVECTION ALONG THE CORDILLERA AND VERY
LIGHT AMOUNTS IN SOUTHWEST PUERTO RICO AS CELLS DISSIPATE. ON
WEDNESDAY EXPECT MAXIMA NEAR 1 INCH IN PORTIONS OF THE
CORDILLERA...DECREASING TO MAXIMA NEAR 0.75 INCHES ON THURSDAY.

AVAILABLE MOISTURE IS THEN FORECAST TO GRADUALLY BUILD...WHILE THE
REGION REMAINS UNDER A BROAD UPPER TROUGH PATTERN. MODELS ARE
STRUGGLING TO AGREE ON THE DEGREE OF THE INCREASE IN AVAILABLE
MOISTURE...BUT THE TREND IS EVIDENT IN SEVERAL GUIDANCE MEMBERS.
ACCORDINGLY...WE ARE REFLECTING AN INCREASE IN PRECIPITATION
AMOUNTS STARTING FRIDAY...WHERE EXPECT MAXIMA OF 0.2-0.4 INCHES IN
THE VI AND MAXIMA OF 0.4-0.8 INCHES IN EASTERN PUERTO RICO AND IN
THE CORDILLERA. ON SATURDAY EXPECT MAXIMA OF 0.4-0.7 INCHES IN THE
NORTHERN VI...WHILE AFTERNOON CONVECTION CONCENTRATES IN THE
CORDILLERA YIELDING TO POTENTIAL MAXIMA OF 1-1.5 INCHES IN
SOUTHWEST PUERTO RICO.

GALVEZ...WPC (USA)