980  
FXCA62 TJSJ 131854  
AFDSJU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN JUAN PR  
254 PM AST TUE JAN 13 2026  
   
..NEW SHORT TERM, LONG TERM, AVIATION  
 
   
KEY MESSAGES  
 
ISSUED AT 253 PM AST TUE JAN 13 2026  
 
* SEASONAL CONDITIONS WILL PREVAIL ACROSS THE REGION WITH PASSING  
TRADE-WIND SHOWERS AFFECTING THE WINDWARD AND COASTAL AREAS OF  
PUERTO RICO AND THE U.S. VIRGIN ISLANDS DURING THE MORNING AND  
EVENING HOURS.  
 
* LOCALIZED AFTERNOON SHOWERS WILL LEAD TO A LIMITED FLOODING RISK  
ACROSS PORTIONS OF CENTRAL AND WESTERN PUERTO RICO EACH DAY.  
 
* A MODERATE RISK OF LIFE-THREATENING RIP CURRENTS WILL CONTINUE  
ALONG THE NORTH AND EAST-FACING BEACHES OF PUERTO RICO, CULEBRA  
& ST. CROIX THROUGH THE END OF THE WORKWEEK.  
 
* MARINE AND COASTAL CONDITIONS WILL DETERIORATE THIS WEEKEND WITH  
THE ARRIVAL OF A NORTHWESTERLY SWELL AND STRONGER WINDS. RESIDENTS  
AND VISITORS ARE URGED TO FOLLOW THE CONDITIONS CLOSELY AS THE  
WEEK PROGRESSES.  
 
 
 
   
SHORT TERM(THIS EVENING THROUGH THURSDAY)  
 
ISSUED AT 253 PM AST TUE JAN 13 2026  
 
HIGH-LEVEL CLOUDINESS PREVAILED THROUGHOUT MOST OF THE MORNING  
ACROSS ALL THE ISLANDS, ACCOMPANIED BY LIGHT TO MODERATE SHOWERS  
AFFECTING THE EXPOSED WATERS AND BRIEFLY STREAKING OVER THE  
EASTERN SIDES OF THE ISLANDS. AS OF 12 PM, SATELLITE IMAGERY  
SHOWED THE CLOUDINESS DEVELOPMENT, MOSTLY ACROSS THE INTERIOR INTO  
THE WESTERN INTERIOR. THEREFORE, SHOWER ACTIVITY DEVELOPED ACROSS  
THOSE AREAS WITH LIGHT TO MODERATE SHOWER ACTIVITY. RAINFALL  
ACCUMULATIONS FROM THE DOPPLER RADAR WERE MINIMAL, WITH THE  
HIGHEST VALUE IN TRUJILLO ALTO AT ALMOST HALF AN INCH. DAYTIME  
TEMPERATURES WERE NEAR SEASONAL VALUES. ACCORDING TO UNOFFICIAL  
STATIONS, TEMPERATURES WERE IN THE MID- TO UPPER 80S ACROSS  
COASTAL AREAS AND NEAR THE UPPER 70S AND LOWER 80S IN THE  
INTERIOR.  
 
FOR THE REST OF THE PERIOD, THE WEATHER WILL REMAIN MOSTLY STABLE  
AS THE MID- TO UPPER-LEVEL RIDGE CONTINUES TO DOMINATE THE  
ATMOSPHERIC PATTERN. MEANWHILE, AT THE SURFACE, A STRONG AND BROAD  
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN AN EASTERLY WIND  
FLOW. UNDER THIS SURFACE PATTERN, A PATCH OF SHALLOW MOISTURE WILL  
FILTER IN, WITH PRECIPITABLE WATER VALUES OF 1.2 INCHES, AS SHOWN  
BY GOES-DERIVED SATELLITE IMAGERY, EXCEEDING CLIMATOLOGICAL  
NORMAL. THESE SURFACE CONDITIONS WILL BE ENOUGH TO TRIGGER A  
VARIABLE WEATHER PATTERN TONIGHT, WITH OCCASIONAL SHOWERS ACROSS  
EASTERN SECTIONS OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS.  
WEATHER CONDITIONS WILL SLIGHTLY CHANGE AS THE BROAD SURFACE HIGH  
PRESSURE EXTENDS FARTHER INTO THE WESTERN ATLANTIC AND AS SOME  
INFLUENCE FROM THE FRONTAL BOUNDARY LOCATED NORTH OF THE REGION.  
AS A RESULT, VEERING WINDS WILL BE PRESENT, AND A SOUTHEASTERLY  
FLOW WILL BE PREDOMINANT ON WEDNESDAY INTO THURSDAY. UNDER THIS  
WIND FLOW, MOISTURE FROM THE CARIBBEAN WILL MOVE INTO THE ISLANDS,  
PEAKING THE 850-500 MB RELATIVE HUMIDITY AT THE 75TH PERCENTILE ON  
WEDNESDAY. THEREFORE, THE FORECAST CALLS FOR A MORE SHOWERY  
PATTERN, WITH FREQUENT SHOWERS ACROSS EASTERN SECTIONS AND  
AFTERNOON CONVECTION ACROSS THE INTERIOR AND NORTHWESTERN PARTS OF  
PUERTO RICO. ON THURSDAY, SIMILAR WEATHER CONDITIONS WILL PERSIST,  
WITH PRECIPITABLE WATER VALUES SIMILAR TO THOSE MOVING INTO THE  
REGION, BUT WITH SOME INSTABILITY AS A DEEP-LAYER TROUGH STALLS  
OVER THE WESTERN ATLANTIC, WEAKENING THE RIDGE OVER THE AREA. AS A  
RESULT, COLDER TEMPERATURES ARE EXPECTED AT 500 MB, WITH POTENTIAL  
FOR ONE OR TWO THUNDERSTORMS, WITH THE AFTERNOON SHOWERS ACROSS  
THE INTERIOR AND NORTHWESTERN PR.  
 
 
   
LONG TERM(FRIDAY THROUGH NEXT MONDAY)  
 
ISSUED AT 502 AM AST TUE JAN 13 2026  
 
ON FRIDAY, MODEL GUIDANCE INDICATES THAT A FRONTAL BOUNDARY WILL  
REMAIN NORTH OF THE REGION, WHILE A PRE-FRONTAL TROUGH MAY ENHANCE  
LOW-LEVEL MOISTURE CONVERGENCE AND ATMOSPHERIC INSTABILITY,  
SUPPORTING A WETTER PATTERN. FRIDAY CURRENTLY APPEARS TO HAVE THE  
GREATEST RAINFALL POTENTIAL, WITH A LIMITED FLOOD RISK MAINLY  
ACROSS WESTERN PUERTO RICO DURING THE AFTERNOON HOURS. ISOLATED  
THUNDERSTORMS CANNOT BE RULED OUT. PRECIPITABLE WATER VALUES ARE  
FORECAST TO RANGE BETWEEN 1.4 AND 1.9 INCHES FROM FRIDAY THROUGH  
SATURDAY, NEAR TO ABOVE CLIMATOLOGICAL NORMALS FOR THIS TIME OF  
YEAR.  
 
LOW-LEVEL WINDS WILL GENERALLY REMAIN FROM THE EAST TO SOUTHEAST  
AT 10 TO 15 MPH ON FRIDAY, THEN SHIFT TO THE EAST TO NORTHEAST BY  
FRIDAY NIGHT INTO SATURDAY WHILE INCREASING TO 15 TO 20 MPH WITH  
GUSTS UP TO 25 TO 30 MPH. BREEZY TO LOCALLY WINDY CONDITIONS ARE  
EXPECTED SATURDAY AND EARLY SUNDAY, WHICH MAY LEAD TO LOOSE OUTDOOR  
ITEMS BEING BLOWN AROUND, ESPECIALLY ACROSS EXPOSED AND COASTAL  
AREAS.  
 
FROM SUNDAY THROUGH TUESDAY, PRECIPITABLE WATER VALUES ARE  
EXPECTED TO DECREASE TO BETWEEN 1.2 AND 1.5 INCHES, WITH PATCHES  
OF NEAR-AVERAGE MOISTURE MOVING ACROSS THE REGION. THIS WILL  
SUPPORT MORE VARIABLE BUT SEASONABLE CONDITIONS, WITH PASSING  
TRADE WIND SHOWERS AND LIMITED CONVECTIVE DEVELOPMENT EACH  
AFTERNOON. NO FLOODING CONCERNS AT THIS TIME.  
 
A SUBTROPICAL JET STREAK NEAR 250 MB WILL ESTABLISH A FAVORABLE  
DYNAMIC PATTERN FROM TUESDAY NIGHT INTO WEDNESDAY, SUPPORTING  
UPPER-LEVEL DIVERGENCE AND AN INDUCED SURFACE TROUGH. AS A RESULT,  
AN INCREASE IN THE FREQUENCY OF SHOWERS IS EXPECTED ACROSS THE  
FORECAST AREA UNDER A NORTHEASTERLY LOW-LEVEL WIND FLOW. CONTINUE  
TO MONITOR THE FORECAST UPDATES.  
 
TEMPERATURE-WISE, ENSEMBLE GUIDANCE CONTINUES TO INDICATE NEAR  
SEASONAL TO ABOVE-NORMAL TEMPERATURES ACROSS PUERTO RICO AND THE  
U.S. VIRGIN ISLANDS THROUGHOUT THE LONG-TERM PERIOD.  
 
 
   
AVIATION  
 
(18Z TAFS)  
ISSUED AT 253 PM AST TUE JAN 13 2026  
 
VFR CONDITIONS WILL PERSIST ACROSS ALL TAF SITES DURING THE  
PERIOD. VCSH TO SHRA WILL CONTINUE NEAR TJSJ, TJBQ & TJPS FROM NOW  
THROUGH 13/22Z. WINDS WILL PERSIST FROM THE E-NE UP TO 11 KNOTS  
WITH SEA BREEZE VARIATION, DIMINISHING AT 14/03Z./ HI-RESOLUTION  
MODELS SHOW AN INCREASE IN SHOWER ACTIVITY ACROSS THE EASTERN TAF  
SITES FROM 13/23Z TO 14/12Z. NO SIGNIFICANT OPERATIONS ARE  
FORECAST.  
 
 
   
MARINE  
 
ISSUED AT 253 PM AST TUE JAN 13 2026  
 
A SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC AND A SURFACE  
TROUGH TO THE NORTH OF THE REGION WILL MAINTAIN GENTLE TO MODERATE  
EAST TO NORTHEAST WINDS THROUGH WEDNESDAY, THEN SHIFTING FROM THE  
EAST TO SOUTHEAST BY THURSDAY. THIS PATTERN WILL SUPPORT PASSING  
TRADE- WIND SHOWERS, MAINLY ACROSS THE ATLANTIC WATERS, WITH  
OCCASIONAL SHOWERS ALSO MOVING THROUGH THE CARIBBEAN PASSAGES. BY  
SATURDAY, STRENGTHENING EAST TO NORTHEAST WINDS AND THE ARRIVAL OF  
A LONG- PERIOD NORTHERLY SWELL WILL LIKELY RESULT IN CHOPPY TO  
ROUGH SEAS, LEADING TO HAZARDOUS MARINE CONDITIONS DURING THE  
WEEKEND. MARINERS ARE ADVISED TO CONTINUE MONITORING THE FORECAST.  
 
 
   
BEACH FORECAST  
 
ISSUED AT 253 PM AST TUE JAN 13 2026  
 
A MODERATE RISK OF RIP CURRENTS WILL CONTINUE FOR THE NEXT SEVERAL  
DAYS ALONG THE NORTHERN AND EASTERN BEACHES OF PUERTO RICO, AS  
WELL AS CULEBRA AND ST. CROIX, WITH BREAKING WAVES AROUND 4 FEET.  
A MODERATE RISK MEANS THAT LIFE-THREATENING RIP CURRENTS ARE  
POSSIBLE WITHIN THE SURF ZONE, AND BEACHGOERS SHOULD EXERCISE  
CAUTION AT ALL TIMES.  
 
CONDITIONS ARE LIKELY TO DETERIORATE OVER THE WEEKEND AS WINDS  
INCREASE AND THE ARRIVAL OF A LONG-PERIOD NORTHERLY SWELL. THIS  
WILL LEAD TO A HIGH RIP CURRENT RISK ACROSS ATLANTIC EXPOSED  
BEACHES OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS. FOR MORE  
LOCATION SPECIFIC INFORMATION, CONTINUE TO MONITOR  
WEATHER.GOV/BEACH/SJU.  
 
 
   
SJU WATCHES/WARNINGS/ADVISORIES  
 
PR...NONE.  
VI...NONE.  
AM...NONE.  
 
 
 
 
SHORT TERM/AVIATION...LIS  
LONG TERM....YZR  
PUBLIC, KEY MESSAGES, MARINE & BEACH FORECAST...GRS  
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