964
FXCA62 TJSJ 201834
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
234 PM AST SAT JUN 20 2026
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST
KEY MESSAGES
ISSUED AT 214 PM AST SAT JUN 20 2026
* MODERATE TO HIGH CONCENTRATIONS OF SAHARAN DUST WILL CONTINUE TO
FILTER INTO THE REGION FOR THE REST OF THE HOLIDAY WEEKEND AND
EARLY NEXT WEEK, RESULTING IN HAZY SKIES, REDUCED VISIBILITY, AND
POOR AIR QUALITY. SENSITIVE INDIVIDUALS SHOULD FOLLOW MEDICAL
RECOMMENDATIONS.
* SHOWER AND THUNDERSTORM ACTIVITY ON FATHER’S DAY MAY RESULT IN
PONDING OF WATER OVER ROADWAYS AND MINOR FLOODING OVER PORTIONS OF
THE U.S. VIRGIN ISLANDS AND PUERTO RICO.
* SEASONAL TO WARMER CONDITIONS WILL CONTINUE THIS HOLIDAY WEEKEND
AND EARLY NEXT WEEK, WITH HEAT INDICES RANGING FROM THE MID 90S
AND MID-100S ACROSS URBAN AND LOW-LYING AREAS OF PUERTO RICO AND
THE U.S. VIRGIN ISLANDS.
SHORT TERM(THIS EVENING THROUGH MONDAY)
ISSUED AT 214 PM AST SAT JUN 20 2026
HAZY, WARM CONDITIONS PREVAILED ONCE AGAIN ACROSS PUERTO RICO AND
THE U.S. VIRGIN ISLANDS. THE MORNING STARTED CALM UNDER MOSTLY SUNNY
TO PARTLY CLOUDY SKIES, WITH NO SHOWER ACTIVITY REPORTED ACROSS THE
REGION. MAXIMUM TEMPERATURES REACHED THE UPPER 80S TO LOW 90S ACROSS
THE LOWER ELEVATIONS, AND THE LOW TO MID-80S IN THE HIGHER
MOUNTAINS. BY NOON, THE TEMPERATURE AT THE LUIS MUNOZ MARIN
INTERNATIONAL AIRPORT IN SAN JUAN HIT 89°F. HEAT INDICES ACROSS
THE REGION SURPASSED 100°F, PARTICULARLY ALONG THE LOWER
ELEVATIONS OF THE ISLANDS WHERE A HEAT ADVISORY REMAINS IN EFFECT
UNTIL 5 PM AST. WINDS BLEW FROM THE EAST AT 15 TO 20 MPH, WITH
HIGHER GUSTS AND LOCAL SEA BREEZE VARIATIONS.
MODERATE TO HIGH CONCENTRATIONS OF SAHARAN DUST WILL CONTINUE TO
REACH THE ISLANDS THROUGH THE REST OF THE WEEKEND, CAUSING HAZY
SKIES, REDUCED VISIBILITY, AND POOR AIR QUALITY. SENSITIVE GROUPS,
PARTICULARLY INDIVIDUALS WITH RESPIRATORY CONDITIONS, SHOULD TAKE
NECESSARY PRECAUTIONS TO LIMIT OUTDOOR EXPOSURE AND FOLLOW MEDICAL
GUIDANCE.
A STRONG HIGH-PRESSURE SYSTEM OVER THE CENTRAL ATLANTIC WILL
CONTINUE TO TIGHTEN THE LOCAL PRESSURE GRADIENT, RESULTING IN BREEZY
EAST-EAST SOUTHEAST WINDS THROUGH THE END OF THE PERIOD. AT THE MID-
LEVELS, A RIDGE WILL MAINTAIN STABLE AND DRIER CONDITIONS ALOFT.
MEANWHILE, AN UPPER-LEVEL LOW LOCATED NORTHEAST OF THE CARIBBEAN
WILL CONTINUE TO MIGRATE NORTHWARD, LIFTING ITS INFLUENCE AWAY FROM
THE REGION.
DESPITE THIS STABLE ATMOSPHERIC SETUP, A TROPICAL WAVE IS EXPECTED
TO REACH THE ISLANDS BY SUNDAY (FATHER'S DAY), INCREASING MOISTURE
AND THE POTENTIAL FOR RAIN. THE LATEST MODEL GUIDANCE SUGGESTS
PRECIPITABLE WATER VALUES (PWAT) WILL RISE TO BETWEEN 1.75 AND 1.90
INCHES. AS THIS TROPICAL WAVE PASSES, BRIEF SHOWERS ARE EXPECTED
ACROSS PORTIONS OF EASTERN PUERTO RICO AND THE USVI, FOLLOWED BY
AFTERNOON CONVECTION ACROSS WESTERN PUERTO RICO DRIVEN BY DAYTIME
HEATING AND LOCAL EFFECTS. ANY RAINFALL WOULD BE HIGHLY BENEFICIAL
FOR AREAS CURRENTLY EXPERIENCING ABNORMALLY DRY OR MODERATE DROUGHT
CONDITIONS. HOWEVER, FORECAST CONFIDENCE REMAINS LOW TO MODERATE,
AS THE WAVE IS TIGHTLY EMBEDDED BETWEEN LAYERS OF SAHARAN DUST.
LONG TERM(TUESDAY THROUGH NEXT FRIDAY)
ISSUED AT 214 PM AST SAT JUN 20 2026
THE LONG-TERM PATTERN ALIGNS TOWARDS A TYPICAL JUNE WEATHER
CONDITIONS. MOISTURE CONTENT, RELATIVE HUMIDITY VALUES, AND MID-
LEVEL TEMPERATURES ARE FORECAST TO REMAIN NEAR NORMAL VALUES FOR
THIS TIME OF THE YEAR, SUPPORTING A FAIRLY TYPICAL TRADE-WIND
PATTERN ACROSS THE ISLANDS.
ON TUESDAY, A RELATIVELY STABLE AIR MASS WILL PREVAIL ACROSS THE
REGION. PASSING TRADE-WIND SHOWERS WILL CONTINUE TO AFFECT WINDWARD
AND EASTERN SECTIONS OF THE ISLANDS, WHILE LEEWARD AREAS EXPERIENCE
MOSTLY FAIR WEATHER. TEMPERATURES WILL REMAIN SEASONABLY WARM, WITH
HIGHS IN THE UPPER 80S TO LOW 90S ACROSS COASTAL AND URBAN AREAS.
A TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE REGION ON WEDNESDAY
AND THURSDAY. WHILE THE WAVE WILL BRING AN INCREASE IN LOW-LEVEL
MOISTURE AND RESULT IN A HIGHER FREQUENCY OF PASSING SHOWERS, MODEL
GUIDANCE SUGGESTS PRECIPITABLE WATER VALUES WILL REMAIN NEAR
SEASONAL VALUES. IN ADDITION, MID-LEVEL RELATIVE HUMIDITY VALUES
REMAIN RELATIVELY LOW AND TEMPERATURES NEAR 500 MB STAY CLOSE TO
NORMALS, LIMITING THE POTENTIAL FOR WIDESPREAD DEEP CONVECTION. AS A
RESULT, PERIODS OF PASSING SHOWERS ARE EXPECTED, PARTICULARLY ACROSS
WINDWARD AND EASTERN SECTIONS IN THE MORNING AS WELL AS THE
AFTERNOON CONVECTION ACROSS WESTERN PR, BUT SIGNIFICANT RAINFALL
ACCUMULATIONS ARE NOT ANTICIPATED AT THIS TIME.
BY LATE THURSDAY AND CONTINUING THROUGH SATURDAY, A SLIGHTLY DRIER
AIR MASS WILL FILTER INTO THE REGION. THIS WILL PROMOTE A DECREASE
IN SHOWER COVERAGE AND SUPPORT A RETURN TO A MORE TYPICAL TRADE-WIND
WEATHER PATTERN. ALTHOUGH ISOLATED SHOWERS WILL REMAIN POSSIBLE
ACROSS WINDWARD AREAS, MOSTLY FAIR WEATHER CONDITIONS ARE EXPECTED
ELSEWHERE. TEMPERATURES WILL CONTINUE NEAR SEASONAL NORMALS, AND NO
SIGNIFICANT WEATHER IMPACTS ARE ANTICIPATED THROUGH THE END OF THE
FORECAST PERIOD.
AVIATION
(18Z TAFS)
ISSUED AT 214 PM AST SAT JUN 20 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL TERMINALS
DURING THE NEXT 24 HOURS ACROSS ALL TERMINALS. A DENSE PLUME OF
SAHARAN DUST WILL CONTINUE TO LOWER VIS ACROSS PORTIONS OF THE
LOCAL FLYING AREA. HZ WITH VSBY DROPPING TO NEAR 6 SM WILL
CONTINUE THROUGH THE NEXT FEW DAYS. SHRA WILL FORM ALONG THE
CORDILLERA AND W-PR THRU 20/23Z. E-ESE WINDS AT 12-20 KT WITH SEA
BREEZE VARIATIONS AND STRONGER GUSTS THRU 20/22Z-20/23Z. WINDS
WILL BE CALM TO LIGHT AND VARIABLE OVERNIGHT THRU 21/14Z.
MARINE
ISSUED AT 214 PM AST SAT JUN 20 2026
A BROAD SURFACE HIGH PRESSURE OVER THE CENTRAL ATLANTIC WILL PROMOTE
MODERATE TO LOCALLY FRESH EASTERLY TO EAST-SOUTHEASTERLY WINDS OVER
THE NEXT SEVERAL DAYS. AS THE HIGH STRENGTHENS AND WINDS CONTINUE TO
STRENGTHEN, THESE CONDITIONS WILL LEAD TO CHOPPY SEAS ACROSS LOCAL
WATERS AND CARIBBEAN PASSAGES; SMALL CRAFT SHOULD EXERCISE CAUTION.
LOW TO MODERATE CONCENTRATIONS OF SAHARAN DUST WILL PERSIST
THROUGHOUT THE WEEKEND AND MID-WORKWEEK, RESULTING IN HAZY SKIES,
REDUCED VISIBILITY, AND POOR AIR QUALITY. A TROPICAL WAVE WILL MOVE
ACROSS THE CARIBBEAN BASIN ON SUNDAY INTO MONDAY, INCREASING THE
LIKELIHOOD OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE LOCAL
CARIBBEAN WATERS AND PASSAGES.
BEACH FORECAST
ISSUED AT 214 PM AST SAT JUN 20 2026
THE MODERATE RISK OF RIP CURRENTS CONTINUES ACROSS THE NORTHERN AND
EASTERN EXPOSED BEACHES OF PUERTO RICO, INCLUDING VIEQUES AND
CULEBRA, AS WELL AS THE U.S. VIRGIN ISLANDS. MEANWHILE, THE WESTERN
AND SOUTHERN BEACHES OF PUERTO RICO REMAIN AT A LOW RISK. ALTHOUGH
THERE’S NOT A HIGH RISK OF RIP CURRENTS, BEACHGOERS MUST EXERCISE
CAUTION IF PLANNING TO GO TO BEACHES UNDER A MODERATE RISK, AS LIFE-
THREATENING RIP CURRENTS ARE POSSIBLE ALONG THE SURF ZONE. AS
MENTIONED IN PREVIOUS DISCUSSIONS, THE RISK OF RIP CURRENTS SHOULD
SPREAD ACROSS THE ISLANDS AS WINDS GRADUALLY STRENGTHEN, WITH MOST
BEACHES UNDER A MODERATE RISK ON FATHER’S DAY AND PERSISTING FOR THE
NEXT FEW DAYS.
BESIDES RIP CURRENTS, RESIDENTS AND VISITORS ARE ENCOURAGED TO
CONTINUE TO MONITOR THE LATEST WEATHER FORECAST, AS AFTERNOON
SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED THIS HOLIDAY
WEEKEND AND EARLY NEXT WEEK, WITH THE BEST CHANCE OF ISOLATED
THUNDERSTORMS NEAR COASTAL AREAS OF EASTERN/NORTHWESTERN PUERTO
RICO. BASED ON THE LATEST GEOS-5 DUST AOT, A SERIES OF PLUMES WITH
MODERATE TO HIGH CONCENTRATIONS OF SAHARAN DUST SHOULD ARRIVE AND
FILTER INTO THE REGION OVER THE NEXT FEW DAYS, RESULTING IN HAZY
SKIES, REDUCED VISIBILITY, AND POOR AIR QUALITY. BEACHGOERS
SENSITIVE TO THESE PARTICLES SHOULD CONTINUE TO FOLLOW MEDICAL
RECOMMENDATIONS.
SJU WATCHES/WARNINGS/ADVISORIES
PR...HEAT ADVISORY UNTIL 5 PM AST THIS AFTERNOON FOR PRZ001>005-007-
008-010>013.
VI...HEAT ADVISORY UNTIL 5 PM AST THIS AFTERNOON FOR VIZ001-002.
AM...NONE.
DAY...GRS/MNG
EVE...ICP/MMC
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