436
FXCA20 KWBC 051240
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
839 AM EDT FRI MAY 05 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM MAY
05/12UTC: A BROAD MID-LEVEL TROUGH EXTENDS FROM THE NORTH ATLANTIC
WITH ITS BASE NEAR PUERTO RICO ON FRIDAY MORNING. THIS...AMONG
OTHER FACTORS...IS STIMULATING A SOUTHEASTERLY DIRECTION IN THE
TRADES. THESE PROCESSES ARE DRAWING A 40-45MM PRECIPITABLE WATER
MOIST PLUME NORTHWARD INTO PUERTO RICO AND THE VI. SATELLITE
IMAGERY SHOWS A BAND OF SCATTERED-TO-WIDESPREAD SHALLOW CONVECTION
APPROACHING ST. CROIX FROM THE SOUTHEAST. THIS WILL LIKELY FAVOR
TRANSIENT WET CONDITIONS ACROSS THE ISLANDS ON FRIDAY...FOLLOWED
BY MUCH DRIER CONDITIONS.
ON FRIDAY...THE MOIST PLUME WILL FAVOR SCATTERED LIGHT RAINFALL IN
THE VI AND SOUTHEAST PUERTO RICO IN MORNING HOURS...AND STIMULATE
THE DEVELOPMENT OF STRONGER CONVECTION IN NORTHWEST PUERTO RICO IN
THE AFTERNOON. EXPECT LOCAL MAXIMA OF 1-1.5 INCHES. MUCH DRIER
CONDITIONS ARE EXPECTED ON SATURDAY...AS A DRIER AIR MASS MOVES IN
FROM THE SOUTHEAST...AND THE MID-LEVEL RIDGE
STRENGTHENS...RESULTING IN THE STRENGTHENING OF THE TRADE WIND
CAP. THIS IS CONSISTENT WITH VERY ISOLATED CONVECTION AND MAXIMA
GENERALLY UNDER 0.2 INCHES.
ON SUNDAY AND ON...THE MID-UPPER TROUGH OVER THE NORTH ATLANTIC IS
FORECAST TO DEEPEN...EXTENDING INTO THE CENTRAL CARIBBEAN. THIS
WILL GRADUALLY DESTABILIZE THE LOW-LEVELS...FAVORING A GRADUAL
INCREASE IN VERTICAL MIXING. FURTHERMORE...ENHANCED TRADE WIND
CONVERGENCE TO THE SOUTH OF THE ISLANDS WILL START TO BUILD A
MOIST PLUME THAT IS FORECAST TO ARRIVE ON MONDAY. MODELS ARE STILL
SHOWING DISCREPANCIES WITH THE EVOLUTION...AND THE GFS CONTINUES
TO BE THE WETTEST. GIVEN MORE CONSISTENT REPRESENTATION OF THE
CURRENT DISTRIBUTION OF MOISTURE...WE LEAN TOWARDS A WETTER
SOLUTION. THE CURRENT FORECAST SHOWS SCATTERED CONVECTION
DEVELOPING LATE ON SUNDAY INTO MONDAY MORNING IN THE VI AND
SOUTHEAST PUERTO RICO...SPREADING NORTHEASTWARD AS THE DAY
PROGRESSES. EXPECT ACCUMULATION OF 0.25-0.5 INCHES ACROSS MOST OF
THE VI AND EASTERN PUERTO RICO. UNDER SOUTHEASTERLY TRADE WIND
DIRECTIONS...EXPECT AFTERNOON CONVECTION TO CONTINUE CLUSTERING IN
INTERIOR PORTIONS OF NORTHWEST PUERTO RICO...WHERE EXPECT MAXIMA
OF 0.5-0.75. ELSEWHERE IN THE ISLAND...EXPECT AMOUNTS IN THE
0.1-0.3 INCH RANGE. EXPECT DRIER CONDITIONS ON TUESDAY...BUT UNDER
PERSISTENT SOUTHEASTERLY TRADES...EXPECT AFTERNOON DEVELOPMENT TO
CONTINUE CLUSTERING IN INTERIOR PORTIONS OF NORTHWEST PUERTO RICO
REACHING MAXIMA OF 0.5-1 INCH.
GALVEZ/ACOSTA/ALAMO...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page