213
FXCA62 TJSJ 021923
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
ISSUED BY NATIONAL WEATHER SERVICE MELBOURNE FL
323 PM AST MON JUN 2 2025
KEY MESSAGES
* A DENSE SAHARAN AIR LAYER WILL CONTINUE TO CAUSE HAZY SKIES
ACROSS THE ISLANDS THROUGH AT LEAST TUESDAY.
* BREEZY CONDITIONS ARE EXPECTED THROUGH MIDWEEK.
* DIURNALLY INDUCED AFTERNOON SHOWERS ARE EXPECTED TO DEVELOP EACH
DAY OVER WESTERN PR.
SHORT TERM...TONIGHT THROUGH WEDNESDAY
TODAY’S WEATHER WAS GENERALLY FAIR AND STABLE, WITH A DENSE
SAHARAN AIR LAYER CAUSING HAZY SKIES AND REDUCED VISIBILITY (5-6
MILES). ISOLATED, FAST- MOVING SHOWERS OCCURRED MAINLY OVER
WINDWARD AREAS, PRODUCING MINIMAL RAINFALL. BY 3 PM AST, AN
ISOLATED THUNDERSTORM DEVELOPED OVER NORTHWESTERN PR, AND THE
DOPPLER RADAR ESTIMATED NEAR AN INCH OF RAIN. A HEAT ADVISORY WAS
IN EFFECT FROM 10 AM TO 4 PM FOR NORTHERN, WESTERN, AND SOUTHERN
COASTAL PUERTO RICO, WITH HIGHS NEAR 90°F AND HEAT INDEX VALUES UP
TO 110F. INTERIOR MOUNTAIN VALLEYS REMAINED COOLER, WITH HIGHS
AROUND 80F.
TONIGHT, STABLE AND DRY CONDITIONS WILL PERSIST UNDER A MID-LEVEL
RIDGE, WITH THE SAL MAINTAINING DRY, DUSTY AIR THAT LIMITS CLOUDS
AND RAINFALL. BREEZY TO LOCALLY WINDY CONDITIONS WILL CONTINUE DUE
TO STRONG HIGH PRESSURE, POSING WIND HAZARDS NEAR COASTAL AND
EXPOSED AREAS, INCLUDING THE RISK OF LOOSE OBJECTS BEING BLOWN
AROUND. ANY SHOWERS WILL BE FAST-MOVING AND POSE LITTLE THREAT.
ON TUESDAY AND WEDNESDAY, OVERALL DRY AND STABLE CONDITIONS
WILL CONTINUE WITH PRECIPITABLE WATER DROPPING BELOW NORMAL (~1
INCH), LIMITING RAIN CHANCES. HOWEVER, DIURNALLY INDUCED AFTERNOON
SHOWERS ARE EXPECTED TO DEVELOP OVER WESTERN PR EACH DAY. ALTHOUGH
THE SAL WILL KEEP SKIES HAZY AND SUPPRESS THE OVERALL SHOWER
COVERAGE, ISOLATED THUNDERSTORM DEVELOPMENT CANNOT BE RULED OVER
WESTERN PR. A WIND SURGE WILL SHIFT WINDS FROM THE EAST TO EAST-
NORTHEAST, BRINGING SLIGHTLY COOLER AIR AND QUICK PASSING SHOWERS
ACROSS PORTIONS OF THE USVI AND EASTERN PR DURING THE NIGHTS.
TEMPERATURES WILL STAY NEAR TO SLIGHTLY BELOW SEASONAL AVERAGES.
LONG TERM...THURSDAY THROUGH MONDAY
/FROM PREV DISC ISSUED AT 415 AM AST JUN 2 2025/
A MID TO UPPER LEVEL HIGH WILL MAINTAIN STABLE CONDITIONS ALOFT
THROUGH THE END OF THE WEEK. AT THE SURFACE, HIGH PRESSURE
CENTERED OVER THE EASTERN ATLANTIC WILL KEEP THE TRADE WIND
STRONG, AROUND 15 TO 20 KNOTS, OUT OF THE EAST OR SOUTHEAST.
ON THURSDAY, A WEAK TROUGH WILL SNEAK IN, THOUGH, MOSTLY WORKING
TO ENHANCE THE SHOWER ACTIVITY IN THE AFTERNOON ACROSS WESTERN
PUERTO RICO. LATER ON FRIDAY AND THE WEEKEND, THE TRADE WIND CAP
INVERSION DEVELOPS AGAIN, TRAPPING ALL THE MOISTURE TO THE LOWEST
LEVELS OF THE ATMOSPHERE. CHANCES OF SHOWERS WILL BE LIMITED TO
AFTERNOON CONVECTION ACROSS THE WEST, AND A FEW SHOWERS STREAMING
INTO THE VIRGIN ISLANDS OR EASTERN PUERTO RICO. SOME SAHARAN DUST
WILL FILTER IN TOO, ESPECIALLY BY THE END OF THE WEEK.
CONCENTRATIONS ARE NOT EXPECTED TO BE HIGH, HOWEVER. THEN, ON
MONDAY, THERE IS GOING TO BE AN INCREASE IN MOISTURE AS A TROPICAL
WAVE APPROACHES. THROUGH THE FORECAST PERIOD, TEMPERATURES WILL BE
SEASONABLY WARM, WITH HIGHS IN THE UPPER 80S AND LOW 90S, AND HEAT
INDICES JUST ABOVE 100 DEGREES FOR MOST OF THE COASTAL AND URBAN
AREAS OF THE LOCAL ISLANDS.
AVIATION
(18Z TAFS)
MAINLY VFR CONDITIONS EXPECTED ACROSS ALL TERMINALS DURING THE
NEXT 24 HOURS. HOWEVER, BRIEF SHRA/-TSRA OVER WESTERN PR MAY
CAUSE TEMPO MVFR CONDS AT TJBQ THRU 02/21Z. HZ DUE TO SAHARAN DUST
WILL CONTINUE THROUGH AT LEAST TUE MORNING, CAUSING VSBY TO DROP
BTW 6-8 MILES. THE 02/12Z TJSJ SOUNDING INDICATED ESE WINDS UP TO
23 KT BLO FL050.
MARINE
A SURFACE HIGH PRESSURE OVER THE ATLANTIC BASIN WILL CONTINUE TO
PROMOTE MODERATE TO LOCALLY FRESH TRADE WINDS OVER THE NEXT FEW DAYS.
SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS PORTIONS OF THE
OFFSHORE WATERS AND LOCAL CARIBBEAN PASSAGES. HAZY SKIES AND
REDUCED VISIBILITIES ARE EXPECTED TO CONTINUE THROUGH AT LEAST
TUESDAY DUE TO HIGH CONCENTRATIONS OF SAHARAN DUST OVER THE
REGION.
BEACH FORECAST
BREEZY WINDS WILL MAINTAIN A MODERATE RIP CURRENT RISK FOR THE
SOUTHERN BEACHES OF PUERTO RICO, VIEQUES, CULEBRA, AND SAINT CROIX
THROUGH TUESDAY. THEN, THE MODERATE RIP CURRENT RISK WILL SPREAD
ALONG THE NORTH AND EASTERN BEACHES OF PUERTO RICO AS WELL.
SJU WATCHES/WARNINGS/ADVISORIES
PR...HEAT ADVISORY UNTIL 4 PM AST THIS AFTERNOON FOR PRZ001-003-005-
007-008-010-011.
VI...NONE.
AM...NONE.
SHORT TERM...ICP/DSRT
LONG TERM....ERG
AVIATION/MARINE/BEACH...DSR
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