347
FXCA20 KWBC 071254
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
754 AM EST WED FEB 07 2024
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FEB 07/12UTC:
IN AN UNUSUAL AMPLIFIED LARGE SCALE WEATHER PATTERN OVER THE
ENTIRE AMERICAS...A POTENT UPPER TROUGH HAS AMPLIFIED ACROSS THE
NORTHWEST CARIBBEAN INTO SOUTHERN CENTRAL AMERICA. AS IT INTERACTS
WITH THE SUBEQUATORIAL RIDGE LOCATED IN SOUTHEAST
VENEZUELA...LONG-FETCH SOUTHWESTERLY FLOW IN THE MID AND UPPER
TROPOSPHERE IS OCCURRING OVER THE EASTERN CARIBBEAN...ACCOMPANIED
BY A LARGE AREA OF UPPER DIVERGENCE. IN THE LOW-LEVELS...A MOIST
PLUME EXTENDS FROM VENEZUELA INTO PUERTO RICO AND THE VI. THE
PLUME HAS REACHED IMPRESSIVE AMOUNTS OF PRECIBITABLE WATER IN THE
COLUMN...REACHING NEAR 60MM THIS MORNING ACROSS THE VI. SATELLITE
AND RADAR SHOW SCATTERED CONVECTION ACROSS MOST OF THE VI AND
PORTIONS OF PUERTO RICO PROPAGATING FROM SOUTHWEST TO NORTHEAST.
THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST. CURRENT
UNSEASONABLY WET EVENT IS FORECAST TO GRADUALLY TAMPER THROUGH
THURSDAY...AS BOTH UPPER TROUGH AND MOIST PLUME MEANDER EASTWARD.
A VERY SHARP TRANSITION INTO VERY DRY CONDITIONS IS EXPECTED ON
THURSDAY AFTERNOON/EVENING AS A POST FRONTAL AIR MASS MOVES IN.
THIS WILL FAVOR PRECIPITABLE WATER TO PLUMMET TO NEAR 20MM ON
FRIDAY...REMAINING VERY LOW THROUGH SATURDAY. A SLIGHT INCREASE IN
MOISTURE IS EXPECTED ON SUNDAY...BUT ONLY TO FAVOR A GRADUAL
RETURN TO SEASONAL CONDITIONS.
IN TERMS OF PRECIPITATION...WEDNESDAY IS EXPECTED TO BE THE
WETTEST DAY AS THE CURRENT RAIN EVENT PROGRESSES EASTWARD. THE
LARGEST AMOUNTS ARE EXPECTED IN THE EASTERN VI...WHERE EXPECT
MAXIMA OF 1.5-2 INCHES. IN THE WESTERN VI AND EASTERN PUERTO RICO
EXPECT MAXIMA OF 1-1.5 INCHES...WHILE ELSEWHERE IN PUERTO RICO
EXPECT A RATHER UNIFORM DISTRIBUTION OF ACCUMULATION...FORECAST TO
RANGE BETWEEN 0.4 TO 0.6 INCHES. ON THURSDAY...AS NORTHERLY WINDS
SET IN...EXPECT SHALLOW CONVECTIVE INSTABILITY TO FAVOR SCATTERED
SHOWERS IN MOST OF NORTHERN PUERTO RICO. GIVEN LINGERING HIGH
VALUES OF PRECIPITABLE WATER...RANGING NEAR 40MM...AND ENHANCED
VALUES OF SOIL MOISTURE...WE ARE LEANING TOWARDS THE HIGHER END OF
MODEL FORECAST RAINFALL. EXPECT MAXIMA IN THE 0.25-0.5 RANGE FOR
NORTH-CENTRAL AND NORTHEAST PUERTO RICO. AFTER FRIDAY MORNING AND
THROUGH THE WEEKEND...EXPECT TRACE ACCUMULATION.
GALVEZ/ACOSTA...WPC (USA)
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