092  
FXCA62 TJSJ 090852  
AFDSJU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN JUAN PR  
452 AM AST WED JUL 9 2025  
   
KEY MESSAGES  
 
* DIURNALLY INDUCED AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS  
ARE EXPECTED OVER PORTIONS OF THE CORDILLERA CENTRAL AND WESTERN  
PR EACH DAY. PASSING SHOWERS WILL CONTINUE ACROSS THE USVI AND  
EASTERN SECTIONS OF PR DURING THE NIGHT/EARLY MORNING HOURS.  
 
* BREEZY CONDITIONS ARE EXPECTED THROUGH WEDNESDAY. CHOPPY SEAS  
AND A MODERATE RISK OF RIP CURRENTS WILL PERSIST OVER THE NEXT  
FEW DAYS. THESE MAY CREATE HAZARDOUS CONDITIONS ACROSS THE  
ATLANTIC WATERS.  
 
* MODERATE TO HIGH CONCENTRATIONS OF SAHARAN DUST ARE EXPECTED TO  
RETURN BY THE SECOND PART OF THE WORKWEEK THROUGH AT LEAST  
SUNDAY, RESULTING IN HAZY SKIES, REDUCED VISIBILITY, AND POOR  
AIR QUALITY.  
 
 
   
SHORT TERM...TODAY THROUGH FRIDAY  
 
OVERNIGHT, SCATTERED TO NUMEROUS SHOWERS MOVED ACROSS THE LOCAL  
WATERS, WITH SOME REACHING WINDWARD AREAS OF THE U.S. VIRGIN ISLANDS  
AND PUERTO RICO. THIS ACTIVITY WAS ASSOCIATED WITH A WIND SURGE THAT  
INCREASED LOCAL WINDS AND GENERATED ROUGH SEAS FOR MARINERS. SKIES  
WERE VARIABLY CLOUDY, WITH TEMPERATURES RANGING FROM THE LOW TO MID-  
60S IN THE MOUNTAINS AND VALLEYS TO THE UPPER 70S AND LOW 80S IN  
URBAN COASTAL AREAS.  
 
A WIND SURGE WILL BRING SCATTERED SHOWERS AND STRONGER WINDS ACROSS  
THE REGION STARTING TODAY. FROM THURSDAY TO EARLY FRIDAY MORNING, A  
TROPICAL WAVE ACCOMPANIED BY A BAND OF MOISTURE WITH PRECIPITABLE  
WATER VALUES RANGING FROM 1.85 TO 2.10 INCHES WILL MOVE THROUGH THE  
AREA. HOWEVER, HIGHER CONCENTRATIONS OF SAHARAN DUST EMBEDDED WITHIN  
THE WAVE MAY LIMIT OVERALL SHOWER DEVELOPMENT. AS A RESULT, A  
SIMILAR WEATHER PATTERN IS EXPECTED EACH DAY, WITH PASSING SHOWERS  
ACROSS THE U.S. VIRGIN ISLANDS AND EASTERN PUERTO RICO DURING THE  
NIGHT AND EARLY MORNING, FOLLOWED BY AFTERNOON CONVECTION OVER  
CENTRAL AND WESTERN PUERTO RICO AND STREAMER DEVELOPMENT DOWNWIND OF  
THE USVI AND EL YUNQUE. LOCALIZED IMPACTS MAY INCLUDE PONDING OF  
WATER ON ROADS, POORLY DRAINED AREAS, AS WELL AS URBAN AND SMALL  
STREAM FLOODING, PARTICULARLY DURING HEAVIER THUNDERSTORMS. MOISTURE  
WILL RAPIDLY ERODE AFTER FRIDAY MORNING.  
 
ADDITIONALLY, BASED ON THE LATEST MODEL GUIDANCE, AN AREA OF  
SUSPENDED SAHARAN DUST PARTICLES IS FORECAST TO MOVE ACROSS PUERTO  
RICO AND THE U.S. VIRGIN ISLANDS AS EARLY AS TONIGHT, CONTINUING  
THROUGH THE WEEKEND. THIS WILL RESULT IN HAZY SKIES, REDUCED  
VISIBILITY, AND DETERIORATED AIR QUALITY ACROSS THE REGION.  
SENSITIVE GROUPS SHOULD TAKE PRECAUTIONARY MEASURES, AS AIRBORNE  
PARTICULATES MAY IMPACT RESPIRATORY HEALTH.  
   
LONG TERM...SATURDAY THROUGH WEDNESDAY  
 
THE LATEST MODEL GUIDANCE CONTINUES TO INDICATE THE ARRIVAL OF  
SAHARAN DUST PARTICLES ALONG WITH A NOTABLY DRY AIRMASS THROUGH AT  
LEAST LATE SUNDAY. ADDITIONALLY, MID TO UPPER LEVEL DRY AIR AND A  
REINFORCING TRADE WIND INVERSION WILL FURTHER INHIBIT VERTICAL  
CLOUD DEVELOPMENT, SUPPRESSING WIDESPREAD CONVECTION. WITH THIS  
SETUP, RESIDENTS AND VISITORS IN PUERTO RICO AND THE U.S. VIRGIN  
ISLANDS CAN EXPECT HAZY SKIES, REDUCED VISIBILITY, AND POTENTIAL  
AIR QUALITY CONCERNS, PARTICULARLY FOR INDIVIDUALS WITH  
RESPIRATORY CONDITIONS. BREEZY CONDITIONS WILL PREVAIL THROUGH  
SATURDAY, WITH PERSISTENT EASTERLY WINDS SUPPORTING ABOVE-NORMAL  
TEMPERATURES, ESPECIALLY ACROSS COASTAL AND URBAN AREAS.  
 
BY SUNDAY, A TROPICAL UPPER-TROPOSPHERIC TROUGH (TUTT) IS FORECAST  
TO SHIFT WESTWARD TOWARD HISPANIOLA AND LINGER THERE THROUGH  
MIDWEEK. BEGINNING MONDAY, THE APPROACH OF EASTERLY TRADE WIND  
PERTURBATIONS WILL GRADUALLY ENHANCE MOISTURE LEVELS ACROSS THE  
REGION. AS ATMOSPHERIC MOISTURE INCREASES, SO WILL THE POTENTIAL  
FOR SHOWER AND THUNDERSTORM ACTIVITY.  
 
TUESDAY CURRENTLY APPEARS TO HAVE THE HIGHEST RAINFALL POTENTIAL AS  
A TROPICAL WAVE APPROACHES THE FORECAST AREA, BRINGING DEEPER  
TROPICAL MOISTURE. HOWEVER, THE MOST INTENSE PART OF THE WAVE IS  
EXPECTED TO PASS SOUTH OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS.  
NEVERTHELESS, SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED  
EACH AFTERNOON, ESPECIALLY ACROSS INTERIOR AND WESTERN AREAS. WE  
WILL CONTINUE TO MONITOR CONDITIONS CLOSELY FOR ANY SIGNIFICANT  
CHANGES.  
 
 
   
AVIATION  
 
(06Z TAFS)  
 
MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL TERMINALS.  
HOWEVER, A WIND SURGE WILL BRING SOME PASSING SHRA/+SHRA, WHICH MAY  
CAUSE OCCASIONAL BRIEF PERIODS OF MVFR CIGS AND SHRA OVER E-PR/USVI  
TERMINALS. THEN, EXPECT DIURNALLY INDUCED AFTERNOON TSRA OVER THE  
INTERIOR AND WESTER PR. HIGHER CONCENTRATIONS OF SAHARAN DUST RETURN  
FROM THURSDAY ONWARD AND VISIBILITIES COULD DROP TO 5-6 SM. WINDS  
WILL CONTINUE E-ENE AT 15-20 KT WITH HIGHER GUSTS AND SEA BREEZE  
VARIATIONS AFT 09/13Z.  
 
 
   
MARINE  
 
A WIND SURGE WILL PROMOTE ROUGH SEAS DUE TO MODERATE TO LOCALLY FRESH  
WINDS ACROSS THE LOCAL WATERS, ACCOMPANIED BY SCATTERED TO NUMEROUS  
SHOWERS THROUGH AT LEAST THURSDAY MORNING. ANOTHER EASTERLY  
PERTURBATION WILL REACH THE LESSER ANTILLES LATE TONIGHT, MOVING NEAR  
THE US VIRGIN ISLANDS AND PUERTO RICO BY LATE THURSDAY NIGHT AND  
EARLY FRIDAY MORNING. ANOTHER PULSE OF SUSPENDED SAHARAN DUST  
PARTICLES WILL ARRIVE AS EARLY AS LATE TONIGHT AND PERSIST THROUGH  
THE WEEKEND.  
 
 
   
BEACH FORECAST  
 
INCREASING WINDS OVER THE NEXT SEVERAL DAYS WILL PROMOTE A MODERATE  
RISK OF RIP CURRENTS ACROSS THE EASTERN, NORTHERN, AND SOUTHEASTERN  
BEACHES OF PUERTO RICO, VIEQUES, CULEBRA, ST. THOMAS. AND ST. CROIX.  
LIFE-THREATENING RIP CURRENTS OFTEN OCCUR IN THE VICINITY OF GROINS,  
JETTIES, REEFS, AND PIERS.  
 
 
   
SJU WATCHES/WARNINGS/ADVISORIES  
 
PR...NONE.  
VI...NONE.  
AM...SMALL CRAFT ADVISORY UNTIL NOON AST THURSDAY FOR AMZ711.  
 
SMALL CRAFT ADVISORY UNTIL MIDNIGHT AST TONIGHT FOR AMZ712.  
 
SMALL CRAFT ADVISORY UNTIL 6 AM AST THURSDAY FOR AMZ723.  
 
 
 
 
 
SHORT TERM/MARINE...CAM  
AVIATION...MRR/CAM  
LONG TERM/BEACH FORECAST...MMC  
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