130
FXCA62 TJSJ 241815
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
215 PM AST WED JUN 24 2026
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST
KEY MESSAGES
ISSUED AT 204 PM AST WED JUN 24 2026
* A TROPICAL WAVE WILL CONTINUE TO MOVE SOUTH OF THE REGION TODAY.
THE MOISTURE FIELD COULD REACH THE ISLANDS LATER TODAY,
ENHANCING THE POTENTIAL FOR SHOWERS TODAY AS WELL AS FOR
AFTERNOON SHOWERS AND T-STORMS MAINLY ACROSS INTERIOR TO W-NW
PR.
* HIGH CONCENTRATIONS OF SAHARAN DUST ARE EXPECTED TO REACH THE
U.S. VIRGIN ISLANDS THIS AFTERNOON, AND PUERTO RICO LATER THIS
EVENING. THIS WILL RESULT IN HAZY SKIES, REDUCED VISIBILITY AND
DETERIORATED AIR QUALITY.
* BREEZY TO LOCALLY WINDY ESE WINDS WILL RESULT IN UP TO A
MODERATE RISK OF RIP CURRENTS ACROSS MOST COASTAL AREAS TODAY AS
WELL AS IN CHOPPY SEAS AND SMALL CRAFT EXERCISE CAUTION
CONDITIONS.
* AN UPPER-LEVEL LOW WILL INDUCE A SURFACE TROUGH THAT IS FORECAST
TO CROSS THE REGION ON SATURDAY, PROMOTING LIGHTER WINDS AS WELL
AS A LIMITED FLOODING AND LIGHTNING RISK.
SHORT TERM(THIS EVENING THROUGH FRIDAY)
ISSUED AT 204 PM AST WED JUN 24 2026
TRANQUIL WEATHER CONDITIONS PREVAILED TODAY ACROSS PUERTO RICO AND
THE U.S. VIRGIN ISLANDS UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
BY EARLY AFTERNOON, STREAMER ACTIVITY DOWNWIND OF EL YUNQUE MOVED
OVER PORTIONS OF THE SAN JUAN METRO AREA, LEAVING A FEW ISOLATED TO
SCATTERED SHOWERS WITH MINIMAL ACCUMULATIONS. BY MID-AFTERNOON,
ADDITIONAL SHOWERS BEGAN TO DEVELOP ACROSS CENTRAL AND WESTERN
PUERTO RICO, CAUSING NO SIGNIFICANT IMPACTS, WHILE THE U.S. VIRGIN
ISLANDS OBSERVED MAINLY FAIR WEATHER THROUGHOUT THE DAY. MAXIMUM
TEMPERATURES REACHED THE UPPER 80S TO LOW 90S ACROSS THE LOWER
ELEVATIONS AND THE LOW TO MID-80S IN THE HIGHER MOUNTAINS. NOTABLY,
THE TEMPERATURE AT THE LUIS MUNOZ MARIN INTERNATIONAL AIRPORT IN SAN
JUAN HIT 90°F BY NOON. WINDS BLEW MAINLY FROM THE EAST AT 15 TO 20
MPH, WITH HIGHER GUSTS AND LOCAL SEA BREEZE VARIATIONS.
A TROPICAL WAVE WITH ITS AXIS OVER THE LESSER ANTILLES WILL CONTINUE
TO APPROACH AND MOVE OVER THE EASTERN CARIBBEAN LATER TODAY,
SLIGHTLY INCREASING MOISTURE LEVELS ACROSS THE LOCAL ISLANDS.
PRECIPITABLE WATER (PWAT) VALUES ARE EXPECTED TO REACH 1.50 TO 1.60
INCHES LATER TODAY INTO EARLY THURSDAY; HOWEVER, THE BULK OF THE
MOISTURE, WITH VALUES UP TO 2.0 INCHES, IS EXPECTED TO REMAIN OVER
THE CARIBBEAN SEA, WELL SOUTH OF THE AREA. NONETHELESS, THIS SLIGHT
INCREASE IN MOISTURE, COMBINED WITH DAYTIME HEATING AND LOCAL
EFFECTS, WILL DRIVE A FEW MORE SHOWERS ACROSS CENTRAL AND WESTERN
PUERTO RICO THIS AFTERNOON, BRINGING MINOR LOCALIZED FLOODING
IMPACTS. SIMILAR CONDITIONS ARE EXPECTED ON THURSDAY, PARTICULARLY
DURING THE AFTERNOON HOURS.
FOLLOWING THE PASSAGE OF THE WAVE, A DRIER AIRMASS WILL BEGIN TO
FILTER INTO THE REGION ALONGSIDE HIGH CONCENTRATIONS OF SAHARAN
DUST, STARTING TONIGHT AND PERSISTING THROUGH THE WEEKEND. THIS
PATTERN WILL INHIBIT SHOWER DEVELOPMENT, LEADING TO PREDOMINANTLY
DRY CONDITIONS FOR THE SHORT-TERM FORECAST AS PWAT VALUES DROP TO
BETWEEN 1.20 AND 1.30 INCHES. DUE TO THE INCOMING SAHARAN DUST,
SENSITIVE GROUPS, PARTICULARLY INDIVIDUALS WITH RESPIRATORY
CONDITIONS, SHOULD TAKE THE NECESSARY PRECAUTIONS TO LIMIT OUTDOOR
EXPOSURE AND FOLLOW MEDICAL GUIDANCE.
ABOVE-AVERAGE SEASONAL TEMPERATURES WILL ALSO PERSIST THROUGH THE
WEEKEND, WITH MAXIMUM TEMPERATURES RANGING FROM THE UPPER 80S TO LOW
90S ALONG COASTAL AND URBAN AREAS, AND FROM THE UPPER 70S TO LOW 80S
IN THE HIGHER ELEVATIONS. TEMPERATURES ARE FORECAST TO INCREASE
FURTHER AND BECOME EVEN WARMER BY EARLY NEXT WEEK. RESIDENTS AND
VISITORS ARE STRONGLY URGED TO PRACTICE HEAT SAFETY BY STAYING
HYDRATED, AVOIDING STRENUOUS OUTDOOR ACTIVITIES DURING PEAK HEATING
HOURS, AND NEVER LEAVING CHILDREN OR PETS UNATTENDED IN VEHICLES.
LONG TERM(SATURDAY THROUGH NEXT TUESDAY)
ISSUED AT 328 AM AST WED JUN 24 2026
AT THE BEGINNING OF THE LONG-TERM PERIOD, AN UPPER-LEVEL LOW WILL
INDUCE A SURFACE TROUGH THAT IS EXPECTED TO CROSS THE REGION ON
SATURDAY. THIS FEATURE WILL CAUSE THE SURFACE HIGH PRESSURE OVER THE
CENTRAL ATLANTIC TO WEAKEN, REDUCING THE LOCAL PRESSURE GRADIENT AND
RESULTING IN LIGHTER WINDS THAT WILL GRADUALLY BACK TO THE
NORTHEAST. MOISTURE CONTENT WILL INCREASE TO NEAR-NORMAL LEVELS,
WITH PRECIPITABLE WATER VALUES RANGING FROM 1.60 TO 1.75 INCHES, AND
LOCALLY HIGHER AMOUNTS POSSIBLE. IN ADDITION, SAHARAN DUST
CONCENTRATIONS WILL DECREASE AS THE DUST PLUME MOVES AWAY FROM THE
AREA, LEADING TO IMPROVED AIR QUALITY CONDITIONS. AS A RESULT,
PASSING SHOWERS ARE EXPECTED ACROSS WINDWARD AREAS AND THE VICINITY
OF THE USVI DURING THE EARLY MORNING HOURS, FOLLOWED BY SHOWERS AND
ISOLATED THUNDERSTORMS OVER THE WESTERN SECTORS OF PUERTO RICO
DURING THE AFTERNOON DUE TO THE COMBINATION OF LOCAL EFFECTS AND
DAYTIME HEATING. TEMPERATURES AT 500 MB ARE EXPECTED TO REMAIN ABOVE
NORMAL, AROUND -5 C TO -6 DEGREES C, BUT MAY STILL BE SUFFICIENT TO
SUPPORT A FEW LIGHTNING STRIKES.
ON SUNDAY, DRIER CONDITIONS, WITH BELOW-NORMAL PRECIPITABLE WATER
VALUES, AND LOW CONCENTRATIONS OF SAHARAN DUST WILL BEGIN TO ARRIVE,
ACCOMPANIED BY A SOUTHEAST WIND FLOW. THE PRIMARY HAZARD ON THIS DAY
WILL BE WARM TO HOT CONDITIONS, AS INDICATED BY FORECAST GUIDANCE
SHOWING 925 MB TEMPERATURES AROUND TWO STANDARD DEVIATIONS ABOVE
NORMAL. DAYTIME HIGHS ARE EXPECTED TO REACH THE UPPER 80S TO LOW
90S, AND HEAT INDICES MAY EXCEED 100 DEGREES F, PARTICULARLY ACROSS
COASTAL AND URBAN AREAS. AN ELEVATED HEAT RISK WILL LIKELY PERSIST.
EARLY NEXT WEEK THROUGH MID-WEEK, CURRENT GUIDANCE SUGGESTS THAT A
TROPICAL WAVE MAY APPROACH THE CARIBBEAN BASIN AND INCREASE LOW-
LEVEL MOISTURE ACROSS THE LOCAL ISLANDS. PRECIPITABLE WATER VALUES
ARE FORECAST TO INCREASE TO NEAR-NORMAL OR SLIGHTLY ABOVE-NORMAL
LEVELS BASED ON CLIMATOLOGICAL DATA. THIS WOULD LIKELY ENHANCE
RAINFALL CHANCES, LEADING TO A GREATER FREQUENCY OF SHOWERS AND
AFTERNOON CONVECTION. AT THE SAME TIME, COOLER TEMPERATURES ALOFT
ASSOCIATED WITH LOWER 500 MB TEMPERATURES MAY PROVIDE ADDITIONAL
SUPPORT FOR CONVECTIVE DEVELOPMENT. HOWEVER, SAHARAN DUST IS ALSO
EXPECTED TO BE PRESENT, AND ITS INTERACTION WITH THE INCOMING
MOISTURE REMAINS UNCERTAIN. CONTINUE TO MONITOR THE FORECAST AS
UPDATES BECOME AVAILABLE.
AVIATION
(18Z TAFS)
ISSUED AT 204 PM AST WED JUN 24 2026
VFR CONDS ARE FORECAST ACROSS ALL TAF SITES. AN APPROACHING
TROPICAL WAVE MAY RESULT IN SHRA/TSRA THAT COULD LEAD TO VCSH/VCTS
AT TJSJ/TJBQ THRU 24/23Z. HZ IS FORECAST AFTER THE WAVE PASSAGE
BEGINNING AT TIST AND TISX AFT 24/22Z - 24/23Z AND CONTINUING
THROUGH THE WEEKEND. WINDS WILL REMAIN FROM THE E AT 15 TO 20
KNOTS, WITH HIGHER GUSTS AND SEA BREEZE VARIATIONS THRU 24/23Z,
BECOMING LIGHT AND VRB THRU 25/13Z.
MARINE
ISSUED AT 204 PM AST WED JUN 24 2026
A BROAD HIGH PRESSURE SYSTEM OVER THE CENTRAL ATLANTIC WILL MAINTAIN
MODERATE TO FRESH EASTERLY WINDS ACROSS THE REGIONAL WATERS THROUGH
FRIDAY. THESE CONDITIONS WILL RESULT IN CHOPPY SEAS ACROSS THE
REGIONAL WATERS AND CARIBBEAN PASSAGES, SMALL CRAFT MUST EXERCISE
CAUTION. WINDS WILL WEAKEN AND BECOME GENTLE TO MODERATE FROM THE
NORTHEAST BY FRIDAY NIGHT, AS A SURFACE TROUGH MOVES NORTH OF THE
REGION. SHOWER ACTIVITY ASSOCIATED WITH THE TROUGH MAY INCREASE
ACROSS LOCAL ATLANTIC WATERS ON SATURDAY. AS THE TROUGH MIGRATES
WESTWARD, THE PRESSURE GRADIENT WILL INCREASE AND WINDS WILL
STRENGTHEN, BECOMING MODERATE TO LOCALLY FRESH FROM THE SOUTHEAST.
MODERATE TO HIGH CONCENTRATIONS OF SAHARAN DUST WILL GRADUALLY
FILTER INTO THE REGION TONIGHT, BRINGING HAZY SKIES, REDUCED
VISIBILITY, AND DETERIORATED AIR QUALITY.
BEACH FORECAST
ISSUED AT 204 PM AST WED JUN 24 2026
THE BEACH FORECAST REMAINS ON TRACK, AS THE MODERATE RISK OF RIP
CURRENTS CONTINUES ACROSS MOST BEACHES OF PUERTO RICO AND THE U.S.
VIRGIN ISLANDS, WITH BREAKING WAVES BETWEEN 2 AND 4 FEET. AS
MENTIONED IN PREVIOUS DISCUSSIONS, BEACHGOERS MUST EXERCISE CAUTION,
AS LIFE-THREATENING RIP CURRENTS REMAIN POSSIBLE ALONG THE SURF
ZONE. THE MODERATE RISK WILL CONTINUE THROUGH FRIDAY, THOUGH IT MAY
BECOME LOW AS A SURFACE TROUGH APPROACHES THE REGION AND WINDS
WEAKEN. NEVERTHELESS, BEACHGOERS SHOULD TAKE INTO ACCOUNT THAT LIFE-
THREATENING RIP CURRENTS MAY DEVELOP NEAR GROINS, JETTIES, REEFS,
AND PIERS. BY SUNDAY, AS WINDS STRENGTHEN, THE RISK SHOULD GRADUALLY
BECOME MODERATE. BESIDES RIP CURRENTS, RESIDENTS AND VISITORS ARE
ENCOURAGED TO STAY WEATHER ALERT DUE TO SHOWERS AND ISOLATED
THUNDERSTORMS THAT MAY DEVELOP IN THE AFTERNOONS AND MOVE NEAR
COASTAL AREAS OF WESTERN/NORTHWESTERN PUERTO RICO, PARTICULARLY OVER
THE WEEKEND. ADDITIONALLY, A DENSE PLUME OF SAHARAN DUST WILL MOVE
ACROSS THE LOCAL AREA, RESULTING IN HAZY SKIES, REDUCED VISIBILITY,
AND POOR AIR QUALITY. INDIVIDUALS SENSITIVE TO THESE PARTICLES MUST
FOLLOW MEDICAL RECOMMENDATIONS.
SJU WATCHES/WARNINGS/ADVISORIES
PR...NONE.
VI...NONE.
AM...NONE.
DAY...GRS/MNG
EVE...ICP/YZR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page