733
FXCA62 TJSJ 271810
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
210 PM AST MON OCT 27 2025
..NEW SHORT TERM, AVIATION, MARINE, BEACH FORECAST
KEY MESSAGES
* SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE MOVING INLAND
OVERNIGHT, BRINGING A LIMITED RISK OF FLOODING AND LIGHTNING,
ESPECIALLY ALONG EASTERN AND SOUTHERN COASTAL AREAS.
* ACROSS THE U.S. VIRGIN ISLANDS, OCCASIONAL SHOWERS AND AN ISOLATED
THUNDERSTORM ARE EXPECTED, MAINLY LATE TONIGHT INTO THE MORNING
HOURS.
* BUILDING NORTHERLY SWELLS WILL LEAD TO ROUGHER SEAS AND
INCREASING RIP CURRENT RISKS, BECOMING HIGH ALONG NORTH-FACING
BEACHES BY MIDWEEK.
* THE COMBINATION OF SOUTHERLY WINDS AND HIGH HUMIDITY WILL PUSH
TEMPERATURES AND HEAT INDICES HIGHER OVER THE NEXT FEW DAYS,
LEADING TO EXTREME HEAT RISKS DURING THE DAYTIME HOURS.
SHORT TERM
(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 210 PM AST MON OCT 27 2025
MOSTLY CLOUDY SKIES PREVAILED ACROSS PUERTO RICO AND THE U.S. VIRGIN
ISLANDS TODAY, PLAYING AN IMPORTANT ROLE IN LIMITING STRONG AFTERNOON
CONVECTION. EVEN SO, SCATTERED SHOWERS CONTINUED TO MOVE INLAND FROM
THE WATERS, MAINLY AFFECTING EASTERN PUERTO RICO, WHERE RAINFALL TOTALS
GENERALLY REACHED UP TO A QUARTER OF AN INCH THIS MORNING, ADDING
TO ANOTHER 0.25–0.50 INCHES THAT FELL OVERNIGHT. DESPITE EXTENSIVE
CLOUDINESS, HEATING AND ABUNDANT MOISTURE MAY HELP TRIGGER ADDITIONAL
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE INTERIOR AND NORTHWESTERN
PUERTO RICO IN THE COMING HOURS. DAYTIME HIGHS PEAKED IN THE MID TO
UPPER 80S. WINDS WERE GENERALLY FROM THE EAST-SOUTHEAST AT 10–15 MPH,
WITH SEA-BREEZE VARIATIONS AND OCCASIONAL GUSTS OF 20–25 MPH,
PARTICULARLY ALONG EXPOSED COASTAL AND OPEN AREAS.
MOISTURE ASSOCIATED WITH HURRICANE MELISSA, LOCATED FAR SOUTHWEST OF
THE REGION, WILL KEEP CONDITIONS HUMID AND SOMEWHAT UNSTABLE. EAST-
SOUTHEASTERLY WINDS WILL TRANSPORT ABUNDANT TROPICAL MOISTURE,
CARRYING SHOWERS AND A FEW ISOLATED THUNDERSTORMS INTO SOUTHERN AND
EASTERN PUERTO RICO AND THE U.S. VIRGIN ISLANDS. SOME THUNDERSTORMS
COULD PRODUCE BRIEF GUSTY WINDS AND MINOR FLOODING, ESPECIALLY WHERE
HEAVIER RAINFALL OCCURS. WINDS WILL BE MODERATE OVERALL (13–18 MPH),
BECOMING LIGHT TO CALM AND VARIABLE ACROSS INLAND AREAS OVERNIGHT.
TEMPERATURES WILL REMAIN WARM AND MUGGY IN SOME COASTAL LOCATIONS,
WITH LOWS IN THE LOWER 80S, WHILE COOLER CONDITIONS PREVAIL ACROSS
THE INTERIOR AND MOUNTAINS, WHERE LOWS WILL DROP INTO THE LOWER 60S.
AS MELISSA LIFTS NORTHWARD, A RIDGE ALOFT WILL BUILD OVER THE REGION,
GRADUALLY LIMITING DEEP CONVECTION BUT LEAVING ENOUGH LOW- LEVEL
MOISTURE FOR PASSING TRADE-WIND SHOWERS AND A FEW ISOLATED AFTERNOON
THUNDERSTORMS. WINDS WILL CONTINUE TO VEER, SHIFTING FROM SOUTHEAST
ON TUESDAY TO SOUTH-SOUTHEAST ON WEDNESDAY, KEEPING CONDITIONS WARM
AND HUMID. BY WEDNESDAY NIGHT, A TIGHTENING PRESSURE GRADIENT BETWEEN
MELISSA AND THE ATLANTIC RIDGE COULD RESULT IN BREEZY TO LOCALLY
WINDY CONDITIONS, ESPECIALLY ACROSS COASTAL AND MARINE AREAS. EXPECT
ELEVATED HEAT DURING THE DAY, MUGGY NIGHTS, AND A LIMITED RISK FOR
LOCALIZED FLOODING AND BRIEF GUSTY THUNDERSTORMS THROUGH MIDWEEK.
LONG TERM
(THURSDAY THROUGH MONDAY)
ISSUED AT 401 AM AST MON OCT 27 2025
THE LONG-TERM FORECAST ACROSS THE AREA WILL BE DEPENDENT ON THE
TRACK OF MAJOR HURRICANE MELISSA ONCE IT ENTERS THE WESTERN ATLANTIC
WATERS AND MOVES NORTH OF THE SOUTHEASTERN BAHAMAS AND THE TURKS AND
CAICOS ISLANDS. TRAILING MOISTURE ASSOCIATED WITH MELISSA WILL BEGIN
TO REACH THE LOCAL AREA FROM THURSDAY INTO FRIDAY. ALTHOUGH THE BULK
OF THE MOISTURE IS EXPECTED TO REMAIN OVER HISPANIOLA AND TO THE
WEST OF THE LOCAL AREA, SUFFICIENT MOISTURE CONTENT (WITH PRECIPITABLE
WATER VALUES UP TO 2.25 INCHES) WILL SUPPORT THE DEVELOPMENT OF
AFTERNOON CONVECTIVE ACTIVITY ACROSS THE REGION, PARTICULARLY OVER
NORTHWESTERN PUERTO RICO. BY LATE FRIDAY INTO THE WEEKEND, THE
MOISTURE ASSOCIATED WITH MELISSA WILL BEGIN TO MOVE AWAY FROM THE
AREA AS A STRONG SURFACE HIGH-PRESSURE SYSTEM BUILDS OVER THE
CENTRAL ATLANTIC. THEREFORE, WINDS WILL BE PREVAILING FROM THE
SOUTHEASTERLY-SOUTHERLY DIRECTION THROUGH SATURDAY, WHEN THE WIND
PATTERN WILL SHIFT TO THE EAST IN RESPONSE TO THE SURFACE HIGH.
THIS WEATHER PATTERN WILL LIKELY PREVAIL INTO EARLY NEXT WEEK WITH
AN ADVECTIVE PATTERN PERSISTING DURING THE OVERNIGHT AND MORNING
HOURS. SUBSEQUENTLY, SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED
DURING THE AFTERNOON HOURS ALONG THE CENTRAL MOUNTAIN RANGE AND THE
NORTHWESTERN QUADRANT OF THE ISLAND DUE TO DAYTIME HEATING AND LOCAL
EFFECTS. THE FLOODING THREAT WILL REMAIN LIMITED BUT ELEVATED ACROSS
THE AFOREMENTIONED AREAS.
AVIATION
(18Z TAFS)
ISSUED AT 210 PM AST MON OCT 27 2025
MAINLY VFR CONDS EXPECTED THRU PRD. BRIEF MVFR CONDS PSBL IN SHRA/TSRA,
WITH BRIEF REDS IN VIS/CIGS MAINLY AFT 27/16-22Z, AFFECTING
TJBQ/TJSJ. TRADE-WIND SHRA WILL REMAIN PERSISTENT AT TJSJ/USVI
TERMINALS THRU PRD, PRODUCING BRIEF VIS/CIGS REDUCTIONS AT TIMES.
SFC WINDS SE 10–15 KT, BCMG LGT/VRB AFT 27/23Z UNDER LAND- BREEZE
INFLUENCE. HIGHER GUSTS PSBL NR SHRA/TSRA.
MARINE
ISSUED AT 210 PM AST MON OCT 27 2025
MODERATE EAST-SOUTHEASTERLY WINDS WILL PREVAIL TONIGHT, VEERING
SOUTHEAST ON TUESDAY AND SOUTH-SOUTHEAST BY WEDNESDAY AS MAJOR
HURRICANE MELISSA MOVES NORTHWARD. WINDS WILL INCREASE BY WEDNESDAY
NIGHT, BECOMING LOCALLY WINDY ACROSS THE ATLANTIC WATERS AND
CARIBBEAN PASSAGES DUE TO THE INTERACTION WITH A STRENGTHENING
ATLANTIC HIGH. MARINE CONDITIONS WILL REMAIN ROUGH, WITH A BROADER
AREA OF CONCERN FOR SMALL CRAFT BY MIDWEEK AS NORTHERLY SWELLS AND
STRONGER WINDS SPREAD ACROSS THE LOCAL WATERS. SMALL CRAFT SHOULD
EXERCISE CAUTION, PARTICULARLY ACROSS THE ATLANTIC WATERS AND
CARIBBEAN PASSAGES BY MIDWEEK. A SECOND SWELL EVENT GENERATED BY
HURRICANE MELISSA WILL AFFECT THE AREA OVER THE WEEKEND. SHOWERS AND
ISOLATED THUNDERSTORMS WILL AT TIMES CREATE ADDITIONAL HAZARDS,
INCLUDING GUSTY WINDS, LIGHTNING, AND LOCALLY HIGHER SEAS.
BEACH FORECAST
ISSUED AT 210 PM AST MON OCT 27 2025
A MODERATE RISK OF RIP CURRENTS WILL PERSIST TONIGHT ACROSS MOST
BEACHES OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS, WHERE LIFE-
THREATENING RIP CURRENTS REMAIN POSSIBLE. THE RISK WILL INCREASE TO
HIGH ON WEDNESDAY AND THURSDAY ALONG NORTH-FACING BEACHES OF PUERTO
RICO, CULEBRA, AND ST. CROIX, AS NORTHERLY SWELLS SPREAD ACROSS THE
LOCAL ATLANTIC WATERS AND PASSAGES, MAKING LIFE-THREATENING RIP
CURRENTS LIKELY FOR BEACHGOERS. A BRIEF IMPROVEMENT IS EXPECTED
THURSDAY NIGHT INTO FRIDAY, BEFORE CONDITIONS DETERIORATE AGAIN
DURING THE WEEKEND AS SWELLS FROM HURRICANE MELISSA REACH THE AREA.
IN ADDITION, SHOWERS AND ISOLATED THUNDERSTORMS MAY LOCALLY WORSEN
BEACH AND SURF CONDITIONS, BRINGING GUSTY WINDS, DANGEROUS
LIGHTNING, AND CHOPPY SURF THAT CAN QUICKLY MAKE SWIMMING UNSAFE.
SJU WATCHES/WARNINGS/ADVISORIES
PR...NONE.
VI...NONE.
AM...NONE.
SHORT TERM...ICP
LONG TERM...GRS
AVIATION...ICP
PUBLIC...YZR
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