853
FXCA62 TJSJ 240903
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
503 AM AST FRI OCT 24 2025
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST
KEY MESSAGES
* SHOWERS AND THUNDERSTORMS WILL INCREASE THE FLOODING AND
LIGHTNING RISK TODAY, MAINLY OVER PORTIONS OF SOUTHERN AND
EASTERN PUERTO RICO.
* THUNDERSTORM DEVELOPMENT IS EXPECTED THROUGH THE WEEKEND ACROSS
THE LOCAL WATERS OF THE ISLANDS, WHICH MAY MOVE OVER THE USVI AT
TIMES.
* THE MODERATE RISK OF RIP CURRENTS CONTINUES FOR MOST BEACHES OF
PUERTO RICO AND THE U.S. VIRGIN ISLANDS, PERSISTING THROUGH THE
WEEKEND.
SHORT TERM
(TODAY THROUGH SUNDAY)
ISSUED AT 417 AM AST FRI OCT 24 2025
MOSTLY CLOUDY SKIES WERE OBSERVED ACROSS PUERTO RICO AND THE U.S.
VIRGIN ISLANDS OVERNIGHT. STRONG THUNDERSTORMS WERE NOTED MAINLY
ACROSS THE OFFSHORE AND COASTAL WATERS OF PUERTO RICO, AND MONA
PASSAGE. THE DOPPLER RADAR ESTIMATED BETWEEN 0.25 AND 1.25 INCHES OF
RAIN ALONG THE SOUTHERN TO EASTERN PORTIONS OF PUERTO RICO. ACROSS
THE USVI, LITTLE TO NO RAINFALL WAS DETECTED OVERNIGHT. MINIMUM
TEMPERATURES RANGED FROM THE UPPER-70S TO LOW 80S ACROSS THE LOWER
ELEVATIONS OF THE ISLANDS, AND FROM THE UPPER-60S TO MID-70S ACROSS
THE HIGHER ELEVATIONS OF PUERTO RICO. THE WIND WAS FROM THE
SOUTHEAST AT 10 TO 15 MPH WITH GUSTS UP TO 25 MPH.
A SHOWERY PATTERN WILL CONTINUE DURING THE NEXT FEW DAYS AS POOLING
OF TROPICAL MOISTURE PERSISTS ACROSS THE CARIBBEAN UNDER THE
INFLUENCE OF DISTANT TROPICAL STORM MELISSA, LOCATED OVER THE
CENTRAL CARIBBEAN SEA. THE OVERALL PRECIPITABLE WATER CONTENT IS
EXPECTED TO REMAIN AT OR ABOVE 2.00 INCHES THROUGH THE SHORT-TERM
PERIOD. HI-RES MODEL GUIDANCE, FROM THE NBM AND ECMWF SUGGEST THAT
TODAY WILL BE ANOTHER RAINY DAY/NIGHT ALONG SOUTHERN PR, INCLUDING
PORTIONS OF THE CORDILLERA CENTRAL, WITH RAINFALL TOTALS BETWEEN 1
AND 3 INCHES, AND ISOLATED HIGHER AMOUNTS POSSIBLE ALONG SOUTH-
CENTRAL PR. TAKING INTO CONSIDERATION THE PREVIOUS DAYS RAINFALL
ACROSS THESE AREAS WITH ALREADY SATURATED SOILS, ANY BRIEF PERIOD OF
HEAVY RAINFALL COULD TRIGGER QUICK FLOODING AND RAPID RIVER RISES,
AS WELL AS MINOR LANDSLIDES IN AREAS OF STEEP TERRAIN. THE RAINFALL
PATTERN SHOULD CONTINUE OVER THE SAME AREAS ON SATURDAY, WITH
SOMEWHAT LESSER AMOUNTS THAN TODAY, REGARDLESS, THE FLOOD THREAT
WILL CONTINUE ELEVATED ACROSS THE EASTERN AND SOUTHERN HALF OF PR.
ON SUNDAY, A TRANSITION INTO A MORE SEASONABLE WEATHER PATTERN IS
EXPECTED, WITH THUNDERSTORMS DEVELOPING IN THE AFTERNOON OVER THE
INTERIOR AND WESTERN PR. HOWEVER, POSSIBLE LINGERING CLOUD COVER MAY
DELAY THE ONSET OF AFTERNOON CONVECTION.
LONG TERM
(MONDAY THROUGH FRIDAY)
ISSUED AT 417 AM AST FRI OCT 24 2025
NO MAJOR CHANGES WERE INTRODUCED TO THE LONG-TERM FORECAST, AS
UNCERTAINTY REMAINS HIGH FOR THE NEXT WORKWEEK DUE TO TROPICAL STORM
MELISSA. FROM THE LATEST NATIONAL HURRICANE CENTER BULLETIN, MELISSA
CONTINUES AS A TROPICAL STORM AND IS EXPECTED TO BECOME A MAJOR
HURRICANE BY EARLY NEXT WEEK. MOST GLOBAL SOLUTIONS KEEP SUGGESTING
THAT MELISSA SHOULD APPROACH JAMAICA IN THE NEXT FEW DAYS, THEN
TURNING NORTHWARD, CROSSING CUBA INTO THE ATLANTIC WATERS. COMPARED
TO THE LATEST SOLUTIONS, GFS IS SLIGHTLY TENDING TO A WESTERLY
TRACK, AS THE LATEST RUN SUGGESTS MELISSA MOVING ACROSS HAITI
INSTEAD OF THE DOMINICAN REPUBLIC. ALTHOUGH THERE’S STILL
UNCERTAINTY IN MELISSA’S TRAJECTORY, AS MENTIONED IN THE PREVIOUS
DISCUSSION, HIGH MOISTURE CONTENT ASSOCIATED WITH THE SYSTEM IS
STILL EXPECTED ACROSS THE CWA FOR AT LEAST THE FIRST PART OF THE
WORKWEEK. THE LATEST GUIDANCE CONTINUES TO SUGGEST A MEDIUM CHANCE
(40 - 60%) OF PWAT VALUES BETWEEN 2.0 - 2.2 INCHES, WITH A LOWER
CHANCE OF REACHING 2.4 INCHES. HOWEVER, VARIABILITY SPREADS FROM
SEASONAL TO ABOVE-CLIMATOLOGICAL VALUES FROM TUESDAY ONWARDS. HENCE,
THE MOST LIKELY SCENARIO REMAINS AS WINDS FROM THE SE-S WILL BRING
SHOWERS AND ISOLATED THUNDERSTORMS OVER WINDWARD SECTIONS OF THE
LOCAL ISLANDS EARLY IN THE MORNING, WHILE AFTERNOON CONVECTION CAN
BE EXPECTED ACROSS THE MOUNTAIN RANGES OF PUERTO RICO IF CLOUD
COVERAGE DOES NOT PERSIST EACH DAY. RAINFALL ACCUMULATIONS COULD
LEAD TO PONDING OF WATER OVER ROADWAYS, URBAN, AND POORLY DRAINED
AREAS, LEADING TO URBAN AND SMALL STREAM FLOODING OVER THE
AFOREMENTIONED AREAS. ADDITIONALLY, GUSTY WINDS AND FREQUENT
LIGHTNING MAY PERSIST AS WELL. WEATHER CONDITIONS MAY IMPROVE BY
THE END OF THE PERIOD AS A SURFACE HIGH PRESSURE MAY APPROACH THE
CWA BUT ONCE AGAIN THIS WILL DEPEND ON MELISSA’S TRAJECTORY IN THE
LONG TERM FORECAST.
AVIATION
(06Z TAFS)
ISSUED AT 417 AM AST FRI OCT 24 2025
SHRA/TSRA MOVING FROM THE CARIBBEAN WATERS WILL CONTINUE TO CAUSE
TEMPO MVFR TO BRIEF IFR CONDS AT TJPS THROUGH THE FCST PERIOD. AT
TJSJ/TJBQ, MOSTLY -RA/VCTS EXPECTED THROUGH TONIGHT. MTN TOPS OBSCD
AND BKN/OVC LYRS BTW FL030-FL150 EXPECTED. ACROSS THE USVI
TERMINALS, MOSTLY VFR CONDS EXPECTED WITH OCCASIONAL -SHRA MOVING
OVER THE TERMINALS. WIND FROM THE SSE UP TO 15 KT WITH STRONGER
GUSTS NEAR SHRA.
MARINE
ISSUED AT 417 AM AST FRI OCT 24 2025
THE INTERACTION BETWEEN TROPICAL STORM MELISSA AND A SURFACE HIGH
PRESSURE OVER THE CENTRAL ATLANTIC WILL PROMOTE MODERATE TO LOCALLY
FRESH SOUTHEASTERLY WINDS TODAY, BECOMING MODERATE FROM THE EAST
LATER TONIGHT. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH DISTANT
TROPICAL STORM MELISSA WILL CONTINUE ACROSS REGIONAL WATERS AND
PASSAGES, LEADING TO LOCALIZED HAZARDOUS MARINE CONDITIONS AT TIMES.
MARINERS ARE URGED TO STAY PROTECTED ACROSS THESE WATERS.
BEACH FORECAST
ISSUED AT 417 AM AST FRI OCT 24 2025
TODAY, MOST BEACHES OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS WILL
CONTINUE UNDER A MODERATE RISK OF RIP CURRENTS, EXPECTED TO LAST
THROUGH THE WEEKEND. BEACHGOERS ARE URGED TO PAY ATTENTION TO THE
BEACH CONDITIONS AS LIFE-THREATENING RIP CURRENTS ARE POSSIBLE ALONG
THE SURF ZONE. ADDITIONALLY, BEACHGOERS SHOULD REMAIN WEATHER ALERT
DUE TO OUTER BANDS OF TROPICAL STORM MELISSA PRODUCING SHOWERS AND
THUNDERSTORMS ACROSS COASTAL AREAS, PARTICULARLY OVER THE SOUTHERN
AND EASTERN PORTIONS OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS. BY
THE BEGINNING OF NEXT WEEK, THE RIP CURRENT RISK IS LIKELY TO
INCREASE, LEADING TO HAZARDOUS BEACH CONDITIONS.
SJU WATCHES/WARNINGS/ADVISORIES
PR...NONE.
VI...NONE.
AM...NONE.
SHORT TERM/AVIATION...DS
LONG TERM/MARINE...MNG
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