961
FXCA62 TJSJ 012056
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
456 PM AST SAT MAR 1 2025
SYNOPSIS
A DRY AIR MASS WITH TRACES OF SUSPENDED SAHARAN PARTICLES WILL
LIMIT RAIN ACTIVITY, EXTENDING THE HAZY SKIES. OCCASIONAL LIFE-
THREATENING RIP CURRENTS WILL FORM ACROSS THE LOCAL BEACHES. BREEZY
CONDITIONS WILL PROMOTE CHOPPY SEAS THIS WEEKEND, WITH A MODERATE
RIP OF RIP CURRENTS ANTICIPATED. INSTABILITY WILL INCREASE BY THE
MIDDLE OF NEXT WEEK AS A TROUGH APPROACHES FROM THE WEST.
SHORT TERM...TONIGHT THROUGH MONDAY
DIURNALLY INDUCED AFTERNOON SHOWERS DEVELOPED OVER THE INTERIOR AND
WEST/NORTHWEST SECTIONS OF PR TODAY, ACROSS THE USVI, PASSING
SHOWERS WERE OBSERVED EARLY IN THE MORNING AND MOSTLY SUNNY AND HAZY
SKIES IN THE AFTERNOON. THE DOPPLER RADAR ESTIMATED UP TO 1 INCH OF
RAIN OVER NW PR BEFORE 3 PM AST. A DRIER AIR MASS WITH SAHARAN DUST
WILL MOVE OVER THE ISLANDS THROUGH SUNDAY, PROMOTING HAZY SKIES AND
LIMITED SHOWER ACTIVITY IN GENERAL. HOWEVER, A PULSE OF LOW-LEVEL
MOISTURE WILL MOVE OVER THE ISLANDS ON SUNDAY AFTERNOON, PROMOTING A
TRANSITION TO AFTERNOON SHOWERS DEVELOPING LATE IN THE AFTERNOON
HOURS ACROSS THE NW QUADRANT OF PR, AS WINDS CONTINUE FROM THE EAST
TO SOUTHEAST UP TO 20 MPH.
A WEAK TROUGH IS THEN EXPECTED TO DEVELOP ON MONDAY NORTH OF THE
AREA, AND PASSING SHOWERS ARE EXPECTED TO MOVE ACROSS THE WINDWARD
AREAS DURING THE MORNING HOURS, AND AGAIN IN THE NIGHTTIME. ON
MONDAY, AFTERNOON, CONVECTIVE SHOWER ACTIVITY WILL FOCUS OVER WEST
TO SOUTHWEST PORTIONS OF PUERTO RICO, AS STEERING WINDS START TO
SHIFT FROM THE EAST TO NORTHEAST LEADING TO A SLIGHT INCREASE IN THE
RISK OF EXCESSIVE RAINFALL ACROSS THESE AREAS.
THE EAST-SOUTHEASTERLY FLOW WILL LEAD TO WARMER-THAN-NORMAL
TEMPERATURES, ESPECIALLY ON SUNDAY AFTERNOON. TEMPERATURES AT 925 MB
WILL FLUCTUATE BETWEEN 1 TO 2 STANDARD DEVIATIONS ABOVE THE
CLIMATOLOGICAL MEAN. HIGHS WILL REACH THE LOW TO MID-80S IN THE
LOWER ELEVATIONS OF THE ISLANDS, WITH SOME AREAS HITTING THE UPPER
80S, WHILE HIGHER ELEVATIONS OF PUERTO RICO WILL SEE TEMPERATURES IN
THE UPPER 70S TO LOW 80S.
LONG TERM...TUESDAY THROUGH SATURDAY
FROM PREVIOUS DISCUSSION
A MID TO UPPER LEVEL TROUGH WILL BE APPROACHING THE ISLANDS BY
TUESDAY. A PIECE OF THE JET STREAM WILL ALSO REACH THE ISLANDS,
WHILE TEMPERATURES AT 500 MB WILL COOL DOWN TOO. AS A RESULT,
INSTABILITY ALOFT WILL BE INCREASED, ENHANCING THE POTENTIAL FOR
STRONG AFTERNOON SHOWERS DEVELOPING ACROSS THE INTERIOR OF PUERTO
RICO. THE AREAS THAT WILL RECEIVE THE STRONGEST WINDS WILL DEPEND ON
THE DOMINANT WINDS FOR EACH DAY. EASTERLY WINDS ON MONDAY WILL
TRANSPORT THE SHOWERS TOWARD THE WEST, BUT WINDS WILL BE MORE
SOUTHEASTERLY ON TUESDAY, SO THE NORTHWEST WILL LIKELY EXPERIENCE
THE STRONGEST RAINS. THE WIND FLOW COULD SLOW DOWN BY WEDNESDAY, SO
THE RAIN WILL LINGER ACROSS THE INTERIOR, THEN BEING TRANSPORTED
SOUTHWARD BY THE NORTHERLY MID-LEVEL WINDS. WHILE THE MAIN THREAT IS
EXPECTED TO BE LOCALIZED URBAN AND SMALL STREAM FLOODING, THE
INSTABILITY AND DIURNAL HEATING COULD AID IN THE DEVELOPMENT OF
LIGHTNING TOO, SO THUNDERSTORMS WERE ADDED TO THE FORECAST. BY THE
END OF THE WEEK, YET ANOTHER MID TO UPPER LEVEL TROUGH WILL APPROACH
THE REGION. THE PATTERN WILL AGAIN FAVOR THE FORMATION OF SHOWERS
ACROSS THE INTERIOR AND WESTERN PUERTO RICO EACH AFTERNOON.
EACH DAY OF THE WORKWEEK, THE WINDS WILL ALSO CARRY SOME SHOWERS
OVER EASTERN PUERTO RICO AND THE VIRGIN ISLANDS TOO. IT IS WORTH
MENTIONING THAT MOISTURE CONTENT IS NOT EXPECTED TO BE TOO ABUNDANT,
ACTING AS A LIMITING FACTOR FOR THE INTENSITY OF THE AFTERNOON RAIN.
ALSO, TRACES OF SAHARAN DUST WILL LINGER INTO TUESDAY, RESULTING IN
HAZY SKIES.
AVIATION
(18Z TAFS)
SHRA SHOULD END NEAR TJBQ BY SUNSET TODAY. MAINLY VFR CONDITIONS
EXPECTED ACROSS ALL TERMINALS THROUGH THE FORECAST PERIOD. HOWEVER,
SHRA WILL DEVELOP ONCE AGAIN OVER NW PR BTW 02/17Z-21Z AFFECTING
MAINLY TJBQ WITH TEMPO MVFR CONDS. HZ DUE TO SAHARAN DUST WILL
CONTINUE THROUGH THE PERIOD BUT VSBY WILL REMAIN P6SM. WINDS WILL
CONTINUE ESE AT 10-15 KTS, WITH STRONGER GUSTS, AFTER 02/13Z.
MARINE
A BROAD SURFACE HIGH PRESSURE OVER THE EASTERN ATLANTIC WILL PROMOTE
MODERATE TO LOCALLY FRESH SOUTHEASTERLY WINDS THIS WEEKEND. MODERATE
EAST TO NORTHEAST TRADES RETURN ON TUESDAY. A COLD FRONT WILL MOVE
ACROSS THE WESTERN ATLANTIC, APPROACHING THE ISLANDS FROM THE WEST
MONDAY AND TUESDAY. PASSING SHOWERS WILL CONTINUE ACROSS THE
CARIBBEAN AND ATLANTIC WATERS.
BEACH FORECAST
INCREASING WINDS WILL PROMOTE OCCASIONAL LIFE-THREATENING RIP
CURRENTS FROM AGUADILLA TO FAJARDO, FROM FAJARDO TO SALINAS,
VIEQUES, CULEBRA AND THE US VIRGIN ISLANDS.
SJU WATCHES/WARNINGS/ADVISORIES
PR...NONE.
VI...NONE.
AM...NONE.
SHORT TERM/AVIATION...DS
LONG TERM....PREV DISC
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