512
FXCA20 KWBC 131240
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
839 AM EDT THU APR 13 2023
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM APR
13/12UTC: OVER THE NEXT SEVERAL DAYS...LOCALLY INDUCED CONVECTION
WILL BE THE MAIN DRIVER FOR SIGNIFICANT RAINFALL OVER PUERTO RICO.
THEREFORE...MOST OF THE RAINFALL IS EXPECTED ACROSS WESTERN PUERTO
RICO. HOWEVER...EASTERN PUERTO RICO WILL OBSERVE SOME
RAIN...ESPECIALLY IN THE MORNINGS AND OVERNIGHT HOURS THROUGH
SATURDAY. THE 5-DAY RAINFALL TOTAL IS FORECAST TO BE OVER 3 INCHES
ACROSS WESTERN PUERTO RICO...WHILE EASTERN AND NORTHEASTERN PUERTO
RICO IS FORECAST TO HAVE AROUND 1.5 INCHES. THE USVI WILL OBSERVE
MAINLY AN ADVECTIVE RAINFALL PATTERN AS WELL...AND THE 5-DAY
RAINFALL FORECAST IS AROUND A QUARTER OF AN INCH...BUT ISOLATED
AREAS COULD RECEIVE HIGHER AMOUNTS.
THE OVERALL MOISTURE WILL BE NEAR NORMAL OVER THE NEXT SEVERAL
DAYS...THOUGH IT WILL BE BRIEFLY ABOVE NORMAL ON SATURDAY. THERE
IS ALSO A MID-LEVEL RIDGE OVER THE LOCAL AREA DUE TO A MID LEVEL
HIGH PRESSURE ACROSS THE SOUTHWESTERN CARIBBEAN THAT IS MOVING
WEST. THIS MAY CAUSE A WEAK TRADE WIND CAP NEAR 850-750 HPA AT
TIMES. THERE IS ALSO A WEAK UPPER LEVEL RIDGE OVER THE LOCAL AREA.
THE LACK OF DYNAMICS IS THE REASON WHY MAINLY LOCALLY INDUCED
CONVECTION IS EXPECTED. THIS IS THE COMBINATION OF THE AVAILABLE
MOISTURE WITH THE SEA BREEZE CONVERGENCE AND DIURNAL HEATING. A
SURFACE FRONT IS FORECAST TO REACH 20-22N BY FRIDAY...WHILE
GRADUALLY WEAKENING. ALTHOUGH THE FRONT IS NOT FORECAST TO REACH
PUERTO RICO...ENHANCED NORTH EASTERLIES FROM THIS EVENING THROUGH
SATURDAY WILL ENHANCE SHALLOW CONVECTIVE INSTABILITY SUFFICIENTLY
TO FAVOR A SLIGHT ENHANCEMENT OF LATE EVENING/EARLY MORNING TRADE
WIND SHOWERS IN NORTHEASTERN AND EASTERN PUERTO RICO.
IN TERMS OF EXPECTED TOTALS...UNDER THE INFLUENCE OF EASTERLY WIND
FLOW...THE HIGHEST ACCUMULATIONS ARE EXPECTED ACROSS WESTERN
PUERTO RICO EACH AFTERNOON. TODAY...EXPECT MAXIMA OF 1.0-1.5
INCHES. THIS DECREASES TO 0.75-1.0 INCHES ON FRIDAY AND SATURDAY.
ON SUNDAY AND MONDAY...EXPECT MAXIMA OF 0.4-0.6 INCHES. FOR THE
USVI...IN GENERAL...AROUND A TENTH OF AN INCH OR LESS ARE FORECAST
EACH DAY.
ALAMO/ACOSTA...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page