026  
FXCA62 TJSJ 300835  
AFDSJU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN JUAN PR  
435 AM AST MON JAN 30 2023  
   
SYNOPSIS
 
VARIABLE WEATHER CONDITIONS WILL CONTINUE TO PERSIST  
ACROSS THE LOCAL AREA FOR THE NEXT SEVERAL DAYS. PERIODS OF  
SUNSHINE AND PASSING SHOWERS WILL CONTINUE TO BE OBSERVED FROM  
TIME TO TIME, MAINLY OVER THE NORTHERN AND EASTERN PORTIONS OF  
PUERTO RICO AND THE US VIRGIN ISLANDS. CHOPPY TO HAZARDOUS SEAS  
CONTINUE ACROSS THE LOCAL NEARSHORE AND OFFSHORE WATERS.  
THEREFORE, SMALL CRAFT ADVISORIES ARE IN EFFECT FOR MOST OF THE  
MARINE ZONES. THERE IS A HIGH RISK OF RIP CURRENTS ALONG THE NORTH  
AND EAST FACING BEACHES OF PUERTO RICO, SAINT THOMAS, SAINT JOHN  
AND SAINT CROIX.  
 

 
   
SHORT TERM...TODAY THROUGH WEDNESDAY
 
 
CHOPPY TO HAZARDOUS SEAS ACROSS THE ATLANTIC WATERS AND PASSAGES,  
AND LIFE-THREATENING RIP CURRENTS ALONG THE NORTH AND EAST FACING  
BEACHES OF THE ISLANDS WILL CONTINUE TO BE THE MAIN THREATS THROUGH  
THE SHORT TERM PERIOD. TODAY'S SHOWERS MAY CAUSE PONDING OF WATER IN  
ROADS AND POOR DRAINAGE AREAS ACROSS NORTHEASTERN PR. NORMAL TO  
BELOW NORMAL DAYTIME TEMPERATURES ARE EXPECTED TO CONTINUE IN  
GENERAL DUE TO THE MEAN NORTHEASTERLY WIND FLOW.  
 
A BROAD MID-TO UPPER-LEVEL RIDGE CENTERED OVER CUBA WILL BE THE  
DOMINANT WEATHER FEATURE THROUGH MIDWEEK. THIS WILL CONTINUE TO  
PROMOTE DRIER AIR AND STABLE CONDITIONS ALOFT. THE TRADE WIND CAP  
WILL CONTINUE TO PUSH FRAGMENTED LOW-LEVEL MOISTURE AND LOW-LEVEL  
CLOUDS AT TIMES ACROSS THE REGION. THIS NORTHERLY COOLER AIR MOVING  
OVER WARMER WATERS NEAR THE ISLANDS WILL PROMOTE AN ADVECTIVE  
PATTERN, WITH SHOWERS DEVELOPING AND MOVING FROM TIME TO TIME ACROSS  
THE USVI AND ACROSS THE NORTH AND EASTERN SECTIONS OF PR. IN  
ADDITION, DUE TO THE STRONGER THAN NORMAL TRADES, SHOWERS ARE  
EXPECTED TO MOVE FURTHER INLAND OVER CENTRAL PR. HOWEVER, MINOR  
RAINFALL ACCUMULATIONS ARE EXPECTED WITH THIS ACTIVITY. LIGHT  
AFTERNOON SHOWERS MAY DEVELOP OVER SW PR IF THE SEA BREEZE CAN  
OVERCOME THE MEAN NORTHEASTERLY WIND FLOW.  
 

 
   
LONG TERM...WEDNESDAY THROUGH SUNDAY
 
 
THE CURRENT FORECAST CONTINUES ON TRACK. A SURFACE HIGH PRESSURE  
LOCATED IN THE WESTERN TO CENTRAL ATLANTIC IS FORECASTED TO BE THE  
DOMINANT FEATURE ACROSS THE LOCAL AREA. LOCAL WEATHER IS EXPECTED  
TO BE VARIABLE WITH PATCHES OF MOISTURE DRAGGED BY THE TRADE  
WINDS. THESE PATCHES WILL SUPPORT SHOWER ACTIVITY ACROSS THE  
NORTHERN, NORTHEASTERN AND EASTERN PUERTO RICO AT TIMES AND AS  
WELL THE US VIRGIN ISLANDS. THE GENERAL WIND FLOW WILL CONTINUE  
FROM THE EAST TO NORTHEAST, SUPPORTING AFTERNOON CONVECTION ACROSS  
THE WESTERN PORTIONS OF PUERTO RICO WITH SHOWERS THAT COULD LEAD  
TO PONDING OF WATER IN ROADS AND POOR DRAINAGE AREAS. BY THE  
SECOND HALF OF THE LONG TERM PERIOD, A SMALL PERTURBATION COMING  
FROM THE EAST WILL INCREASE THE POTENTIAL FOR MORE SHOWERS ACROSS  
THE LOCAL AREA. A SLIGHT CHANGE ON THE WIND FLOW FROM THE EAST TO  
SOUTHEAST WILL BRING MORE HUMIDITY, INCREASING THE FREQUENCY OF  
SHOWERS TOWARDS THE CENTRAL INTERIOR AND NORTHWESTERN PORTIONS OF  
PUERTO RICO. THE PRECIPITABLE WATER CONTENT VALUES BETWEEN 1.35 TO  
1.62 INCHES INDICATES A HUMID A WETTER PATTERN FOR THE END OF THE  
PERIOD. TEMPERATURES ACROSS THE ISLANDS ARE EXPECTED TO BE LOWER  
THAN NORMAL DUE TO THE NORTHEAST WINDS. EXPECT COOLER  
TEMPERATURES, ESPECIALLY OVER THE MOUNTAINS DURING THE OVERNIGHT  
HOURS.  
 

 
   
AVIATION
 
MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL  
TERMINALS DURING THE NEXT 24 HOURS. HOWEVER, QUICK PASSING SHOWERS  
MAY CAUSE BRIEF MVFR CIGS AT THE USVI TERMINALS BTW 12Z-20Z, AND IN  
TJSJ BTW 20Z-23Z. LOW-LEVEL WINDS WILL CONTINUE FROM THE ENE AT 12-  
18 KT WITH STRONGER GUSTS.  
 

 
   
MARINE
 
MODERATE TO LOCALLY FRESH NORTHEAST WINDS UP TO 20  
KNOTS WITH HIGHER GUSTS, AND SMALL NORTHEASTERLY SWELL WILL  
MAINTAIN HAZARDOUS MARINE CONDITIONS ACROSS MOST LOCAL WATERS. SMALL  
CRAFT ADVISORIES REMAIN IN EFFECT FOR THE NEARSHORE AND OFFSHORE  
ATLANTIC WATERS, OFFSHORE CARIBBEAN WATERS, ANEGADA AND MONA  
PASSAGES, AND THE COASTAL WATERS OF NORTHWESTERN PUERTO RICO.  
FOR THE REST OF THE WATERS, SMALL CRAFT OPERATORS SHOULD CONTINUE  
TO EXERCISE CAUTION DUE TO CHOPPY MARINE CONDITIONS, WITH WIND-  
DRIVEN SEAS OF UP TO 6 FEET. FOR BEACHGOERS, A HIGH RISK OF RIP  
CURRENTS REMAINS IN EFFECT FOR MOST NORTH-AND EAST-FACING BEACHES  
OF PUERTO RICO, CULEBRA, AND ALL THE US VIRGIN ISLANDS, WHERE  
LIFE-THREATENING RIP CURRENTS ARE LIKELY.  
 

 
   
SJU WATCHES/WARNINGS/ADVISORIES
 
 
PR...HIGH RIP CURRENT RISK THROUGH LATE TUESDAY NIGHT FOR PRZ001-002-  
005-008-012.  
 
VI...HIGH RIP CURRENT RISK THROUGH LATE TUESDAY NIGHT FOR VIZ002.  
 
HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR VIZ001.  
 
AM...SMALL CRAFT ADVISORY UNTIL 8 AM AST WEDNESDAY FOR AMZ710-712-715-  
741.  
 
SMALL CRAFT ADVISORY UNTIL 2 PM AST TUESDAY FOR AMZ722.  
 
SMALL CRAFT ADVISORY UNTIL 2 AM AST TUESDAY FOR AMZ732-742.  
 

 
 

 
 
DSR/GRS  
 
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