597
FXCA62 TJSJ 130746
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
346 AM AST SUN APR 13 2025
SYNOPSIS
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE
EAST, NORTH, WEST AND INTERIOR OF PUERTO RICO, WITH ADDITIONAL
SHOWERS ALSO STREAMING OVER THE VIRGIN ISLANDS AT TIMES. THIS WILL
MAINTAIN THE THREAT FOR URBAN AND SMALL STREAM FLOODING ELEVATED
THROUGH MUCH OF THE FORECAST PERIOD. CONDITIONS ARE EXPECTED TO
IMPROVE ON THE NEXT WEEKEND. TEMPERATURES WILL BE ABOVE NORMAL,
MOSTLY FOR URBAN AND COASTAL AREAS THAT DO NOT EXPERIENCE THE
AFTERNOON RAIN ACTIVITY.
SHORT TERM...TODAY THROUGH TUESDAY
MOSTLY TRANQUIL CONDITIONS PREVAILED ACROSS THE ISLANDS, UNDER
PARTLY CLOUDY SKIES. PASSING SHOWERS WERE OBSERVED MOVING OVER
PORTIONS OF SOUTHEASTERN AND SOUTHERN PUERTO RICO, LEAVING MINIMAL
ACCUMULATIONS. MINIMUM TEMPERATURES STAYED IN THE MID TO UPPER 70S
IN THE COASTAL AREAS, AND IN THE MID TO UPPER 60S IN THE MOUNTAINS.
WINDS PREVAILED FROM THE SOUTHEAST AT 5 TO 10 MPH.
A WEAK COLD FRONT WILL CONTINUE TO MOVE TOWARDS THE LOCAL AREA
TODAY. AS THE FRONT APPROACHES THE AREA, ADDITIONAL MOISTURE WILL
CONTINUE TO BE PULLED FROM THE CARIBBEAN WATERS INTO THE AREA. THE
PRECIPITABLE WATER CONTENT WILL REMAIN ABOVE-NORMAL ACROSS THE
REGION WITH VALUES UP TO 2.2 INCHES THROUGH TUESDAY. THEREFORE, THE
AVAILABLE MOISTURE IN COMBINATION WITH SUFFICIENT INSTABILITY OVER
THE AREA WILL ENHANCE THE POTENTIAL TO OBSERVE THE DEVELOPMENT OF
STRONG SHOWERS AND THUNDERSTORMS EACH AFTERNOON. TODAY, THE
STRONGEST ACTIVITY IS EXPECTED OVER THE INTERIOR AND NORTHWESTERN
PUERTO RICO. HOWEVER, WINDS WILL BEGIN TO SHIFT TONIGHT FROM THE
NORTHEAST IN RESPONSE OF A SURFACE HIGH PRESSURE MOVING FROM THE
WESTERN TO CENTRAL ATLANTIC. BY MONDAY, THE SHOWER ACTIVITY IS
ANTICIPATED TO AFFECT THE SOUTHWESTERN PORTIONS OF PUERTO RICO AFTER
MID-DAY. ACROSS THE U.S. VIRGIN ISLANDS, MOSTLY FAIR WEATHER IS
ANTICIPATED OVER THE NEXT FEW DAYS, WITH PASSING SHOWERS MOVING INTO
THE AREA DURING THE MORNING HOURS.
FOR THE NEXT SEVERAL DAYS 925 MB TEMPERATURES WILL BE AT NORMAL
TO ABOVE, AND ALSO WITH HIGH HUMIDITY LEVELS ACROSS THE REGION.
HIGHS WILL REMAIN IN THE UPPER 80S TO LOW 90S ACROSS THE COASTAL
AND URBAN AREAS, AND IN THE UPPER 70S TO MID 80S IN THE MOUNTAINS
AND HIGHER ELEVATIONS. A SLIGHT RELIEF IN TEMPERATURES IS EXPECTED
ON MONDAY AS WINDS SHIFT FROM THE NORTHEAST. REMEMBER TO STAY
HYDRATED, WEAR LIGHT CLOTHES, AND TAKE BREAKS IN SHADED AREAS!
LONG TERM...WEDNESDAY THROUGH SUNDAY
UNSETTLED WEATHER CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE
ISLANDS THROUGH AT LEAST EARLY IN THE WEEKEND. ON WEDNESDAY, A
SURFACE LOW PRESSURE WILL DEVELOP NORTH OF THE ISLANDS WHILE
MOVING TOWARD THE NORTHEAST. THIS WILL MAINTAIN A STEADY
SOUTHERLY WIND FLOW FROM THE SURFACE ALL THE WAY UP INTO 700 MB.
THEN, LATE ON WEDNESDAY AND INTO THE END OF THE WEEK, A POLAR
TROUGH WILL MOVE INTO THE WESTERN ATLANTIC. THIS WILL WEAKEN THE
PRESSURE GRADIENT CONSIDERABLY, WITH WIND SPEEDS FALLING FROM
NEARLY 13 KTS ON WEDNESDAY, 7 KTS ON THURSDAY, AND 2-3 KTS ON
FRIDAY. THE WINDS WILL GRADUALLY SHIFT FROM THE SOUTH TOO, PULLING
MOISTURE FROM THE CARIBBEAN INTO THE ISLANDS. AS A RESULT,
SHOWERS WILL CONTINUE TO STREAM AT TIMES OVER EASTERN AND SOUTHERN
PUERTO RICO AND THE VIRGIN ISLANDS AT TIMES. HOWEVER, THE
STRONGEST ACTIVITY IS ANTICIPATED FOR THE INTERIOR, WESTERN AND
NORTHERN PUERTO RICO IN THE AFTERNOON AND EARLY EVENING HOURS. THE
MAIN THREAT WILL BE URBAN AND SMALL STREAM FLOODING, RAPID RIVER
RISES, MUDSLIDES AND LIGHTNING STRIKES FROM THE THUNDERSTORMS.
THIS TROUGH WILL ALSO ESCORT A COLD FRONT INTO THE REGION, AND IT
COULD CROSS THE ISLAND SON SATURDAY, AND WINDS WILL BEGIN TO SHIFT
FROM THE NORTH BY THEN. PLENTY OF MOISTURE SHOULD CONTINUE TO FIRE
UP CONVECTION ACROSS THE CORDILLERA CENTRAL IN THE AFTERNOON
HOURS. AFTER THE FRONT CROSSES THE ISLANDS, DRIER AIR WILL MOVE
IN, WITH COOLER TEMPERATURES, BREEZY CONDITIONS AND LESS RAIN IN
FORECAST.
BEFORE THE FRONT MOVES, FROM WEDNESDAY THROUGH FRIDAY, THE
SOUTHERLY WIND FLOW WILL CAUSE TEMPERATURES TO INCREASE, WITH HEAT
INDICES JUST ABOVE 102 DEGREES FOR URBAN AND COASTAL AREAS. AREAS
WITH A THICK CLOUD LAYER AND FREQUENT SHOWERS WILL SEE A RELIEF
FROM THESE HIGH TEMPERATURES.
AVIATION
(06Z TAFS)
VFR CONDS EXPECTED ACROSS ALL TERMINALS DURING THE FCST PERIOD.
SHRA/TSRA ASSOCIATED WITH A COLD FRONT NEAR THE AREA MAY CAUSE BRIEF
PERIODS OF MVFR CONDITIONS AT TJSJ AND TJBQ THROUGH 13/22Z. MNTN
OBSC IS EXPECTED FOR ALONG THE CORDILLERA CENTRAL IN THE AFTERNOON.
WINDS WILL PREVAIL FROM THE SE AT 10-15 KTS WITH STRONGER GUSTS,
MAINLY NEAR THE STRONGEST SHRA ACTIVITY.
MARINE
A BROAD SURFACE HIGH PRESSURE WILL REMAIN ANCHORED OVER THE CENTRAL
ATLANTIC, PROMOTING LIGHT TO MODERATE EAST TO SOUTHEAST WINDS
THROUGH THE WEEKEND. HOWEVER, ANOTHER SURFACE HIGH PRESSURE WILL
BUILD OVER THE WESTERN ATLANTIC, PUSHING A FRONT OVER THE LOCAL AREA
EARLY IN THE WEEK, PROMOTING MODERATE TO FRESH NORTHEAST WINDS.
SHOWER AND THUNDERSTORM ACTIVITY WILL DEVELOP EACH DAY, MAINLY ACROSS
THE ATLANTIC WATERS AND THE MONA PASSAGE.
BEACH FORECAST
LIGHT WINDS WILL MAINTAIN THE RISK OF RIP CURRENTS LOW TODAY AND
ON MONDAY. HOWEVER, MODERATE WINDS RETURN ON TUESDAY, LEADING TO
MODERATE RISK FOR NORTHERN AND EASTERN PUERTO RICO FOR MOST OF THE
WORKWEEK. BE AWARE THAT AFTERNOON THUNDERSTORMS POSE A THREAT OF
LIGHTNING, MOSTLY FOR THE BEACHES IN THE WEST AND NORTH COAST OF
PUERTO RICO.
SJU WATCHES/WARNINGS/ADVISORIES
PR...NONE.
VI...NONE.
AM...NONE.
SHORT TERM...GRS
LONG TERM....ERG
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