771  
AXPZ20 KNHC 311554  
TWDEP  
 
TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL  
1605 UTC SAT MAY 31 2025  
 
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM  
03.4S TO 30N, EAST OF 120W INCLUDING THE GULF OF CALIFORNIA, AND  
FROM THE EQUATOR TO 30N, BETWEEN 120W AND 140W. THE FOLLOWING  
INFORMATION IS BASED ON SATELLITE IMAGERY, WEATHER OBSERVATIONS,  
RADAR, AND METEOROLOGICAL ANALYSIS.  
 
BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH  
1530 UTC.  
   
..SPECIAL FEATURES  
 
POST-TROPICAL CYCLONE ALVIN IS CENTERED NEAR 20.7N 109.5W AT  
31/1500 UTC, MOVING NORTH AT 8 KT. ESTIMATED MINIMUM CENTRAL  
PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH  
GUSTS TO 40 KT. PEAK SEAS TO 12 FT (4 M) ARE OCCURRING WITHIN 60  
NM IN THE NE QUADRANT AND WITHIN 45 NM IN THE SE, SW AND NW  
QUADRANTS. NO SIGNIFICANT CONVECTION IS OCCURRING SURROUNDING  
ALVIN. A SLIGHTLY SLOWER NORTHWARD MOTION IS EXPECTED THROUGH  
TONIGHT. ALVIN WILL WEAKEN AND BECOME A REMNANT LOW AND MOVE TO  
21.8N 109.7W THIS EVENING, AND DISSIPATE SUN MORNING. SWELLS  
GENERATED BY THIS SYSTEM WILL AFFECT PORTIONS OF THE COASTS OF  
WEST-CENTRAL MEXICO AND THE SOUTHERN BAJA CALIFORNIA PENINSULA  
THROUGH THE WEEKEND. THESE SWELLS ARE LIKELY TO CAUSE LIFE-  
THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE CONSULT  
PRODUCTS FROM YOUR LOCAL WEATHER OFFICE.  
 
PLEASE READ THE LATEST HIGH SEAS FORECAST ISSUED BY THE NATIONAL  
HURRICANE CENTER AT WEBSITE -  
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFEP2.SHTML AND THE LATEST  
ALVIN NHC FORECAST/ADVISORY AND PUBLIC ADVISORY AT  
WWW.HURRICANES.GOV FOR MORE DETAILS.  
   
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH  
 
THE MONSOON TROUGH AXIS EXTENDS FROM 09N79W TO 08N84W TO 13N102W  
TO 06N128W. THE ITCZ CONTINUES FROM 06N128W TO BEYOND 07N140W.  
NUMEROUS STRONG CONVECTION IS OCCURRING FROM 03N TO 10N EAST OF  
90W. SCATTERED MODERATE CONVECTION IS NOTED FROM 04N TO 08N  
BETWEEN 95W AND 100W.  
   
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO  
 
PLEASE SEE THE SPECIAL FEATURES SECTION ABOVE FOR INFORMATION ON  
POST-TROPICAL CYCLONE ALVIN.  
 
A 1013 MB LOW IS CENTERED NEAR 29N119W OFFSHORE OF BAJA  
CALIFORNIA NORTE, AND ISOLATED SHOWERS ARE NOTED SURROUNDING THE  
LOW. LIGHT TO GENTLE WINDS AND SEAS OF 4 TO 6 FT ARE OCCURRING IN  
THIS REGION. ELSEWHERE, TROUGHING HAS BEEN ANALYZED OVER THE  
GULF OF CALIFORNIA, AND GENTLE TO MODERATE WINDS AND SLIGHT SEAS  
ARE NOTED IN THIS REGION. SEAS OF 4 TO 7 FT PREVAIL IN THE  
ENTRANCE OF THE GULF, DUE TO SWELLS FROM ALVIN. OTHERWISE,  
RIDGING EXTENDS THROUGH THE WATERS OFFSHORE OF SOUTHERN MEXICO,  
SUPPORTING GENTLE TO LOCALLY MODERATE E TO SE WINDS AND SEAS OF 5  
TO 7 FT, WITH SEAS NEAR 8 FT OCCURRING OFFSHORE OF MICHOACAN AND  
COLIMA, NEAR ALVIN.  
 
FOR THE FORECAST, IN ADDITION TO IMPACTS FROM POST-TROPICAL  
CYCLONE ALVIN, GENTLE TO LOCALLY MODERATE WINDS ARE EXPECTED  
ACROSS THE MEXICO OFFSHORE WATERS THIS WEEKEND. A LONG-PERIOD SW  
SWELL WILL PROGRESS INTO THE WATERS OFFSHORE OF SOUTHWESTERN  
MEXICO TONIGHT, PRODUCING ROUGH SEAS THROUGH SUN BEFORE SEAS  
DIMINISH EARLY NEXT WEEK. ELSEWHERE, NEW NW SWELL WILL PROMOTE  
ROUGH SEAS OFFSHORE OF BAJA CALIFORNIA NORTE EARLY NEXT WEEK.  
LOOKING AHEAD, AN AREA OF LOW PRESSURE IS LIKELY TO FORM BY THE  
MIDDLE PART OF NEXT WEEK OFFSHORE OF THE COASTS OF CENTRAL  
AMERICA AND SOUTHERN MEXICO. ENVIRONMENTAL CONDITIONS APPEAR  
FAVORABLE FOR SOME DEVELOPMENT OF THIS SYSTEM THEREAFTER, AND A  
TROPICAL DEPRESSION COULD FORM LATE NEXT WEEK WHILE IT MOVES  
GENERALLY WESTWARD TO WEST-NORTHWESTWARD AT AROUND 5 TO 10 MPH.  
THERE IS A MEDIUM CHANCE OF DEVELOPMENT IN THE NEXT 7 DAYS.  
 
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,  
AND WITHIN 750 NM OF ECUADOR...  
 
PREVAILING LOW PRESSURE OVER NORTHWESTERN COLOMBIA MAINTAINS  
MODERATE TO LOCALLY FRESH E TO NE WINDS IN THE GULF OF PAPAGAYO.  
ELSEWHERE, MODERATE TO LOCALLY FRESH SW WINDS ARE NOTED TO THE  
SOUTH OF THE MONSOON TROUGH, WITH GENTLE TO MODERATE WINDS TO THE  
NORTH. A LONG PERIOD SW SWELL IS MOVING THROUGH THE WATERS  
OFFSHORE OF ECUADOR, WITH PEAK SEAS TO 9 TO 10 FT OCCURRING SOUTH  
OF THE GALAPAGOS ISLANDS, AS SEEN ON RECENT ALTIMETER DATA. SEAS  
OF 4 TO 6 FT ARE NOTED ELSEWHERE. NUMEROUS STRONG THUNDERSTORMS  
OCCURRING OFFSHORE OF NICARAGUA THROUGH COLOMBIA, PRECEDING A  
TROPICAL WAVE IN THE CENTRAL CARIBBEAN, WILL PRODUCE GUSTY WINDS  
AND RAPIDLY BUILDING SEAS.  
 
FOR THE FORECAST, A LONG-PERIOD, SOUTHERN HEMISPHERE SWELL WILL  
PROPAGATE NORTHEASTWARD THROUGH THE EQUATORIAL WATERS THIS  
WEEKEND, PROMOTING ROUGH SEAS OFFSHORE OF ECUADOR THROUGH SUN,  
AND WELL OFFSHORE OF GUATEMALA AND EL SALVADOR ON SUN. SEAS WILL  
SUBSIDE EARLY NEXT WEEK. LOOKING AHEAD, AN AREA OF LOW PRESSURE  
IS LIKELY TO FORM BY THE MIDDLE PART OF NEXT WEEK OFFSHORE OF THE  
COASTS OF CENTRAL AMERICA AND SOUTHERN MEXICO. ENVIRONMENTAL  
CONDITIONS APPEAR FAVORABLE FOR SOME DEVELOPMENT OF THIS SYSTEM  
THEREAFTER, AND A TROPICAL DEPRESSION COULD FORM LATE NEXT WEEK  
WHILE IT MOVES GENERALLY WESTWARD TO WEST-NORTHWESTWARD AT AROUND  
5 TO 10 MPH. THERE IS A MEDIUM CHANCE OF DEVELOPMENT IN THE NEXT  
7 DAYS.  
   
..REMAINDER OF THE AREA.  
 
MODERATE TO LOCALLY FRESH N TO NE WINDS ARE OCCURRING NORTH OF  
THE ITCZ AND WEST OF 125W AS A 1027 MB HIGH PREVAILS NORTH OF THE  
REGION, CENTERED NEAR 33N141W. SEAS OF 6 TO 9 FT ARE NOTED IN  
THIS AREA, AS OBSERVED ON RECENT SOFAR BUOY DATA. ELSEWHERE, A  
SOUTHERN HEMISPHERE SWELL IS PROMOTING ROUGH SEAS SOUTH OF 15N  
AND EAST OF 130W, WITH PEAK SEAS NEAR 10 FT. GENTLE TO MODERATE  
S TO SE WINDS PREVAIL SOUTH OF THE MONSOON TROUGH AND ITCZ.  
 
FOR THE FORECAST, ROUGH SEAS IN S TO SW SWELL WILL PROPAGATE  
NORTHEASTWARD TODAY, IMPACTING AREAS SOUTH OF 17N AND EAST OF  
125W THROUGH SUN, BEFORE SEAS SUBSIDE EARLY NEXT WEEK. ELSEWHERE,  
MODERATE TO FRESH NE WINDS AND LOCALLY ROUGH SEAS WILL PREVAIL  
NORTH OF THE ITCZ AND WEST OF 125W TODAY. FRESH NE WINDS AND  
ROUGH SEAS ARE THEN EXPECTED NORTH OF 20N SUN INTO EARLY NEXT  
WEEK AS HIGH PRESSURE STRENGTHENS TO THE NORTH. LOOKING AHEAD,  
FRESH TO LOCALLY STRONG N WINDS AND VERY ROUGH SEAS WILL BE  
POSSIBLE NORTH OF 25N BETWEEN 120W AND 135W BY THE MIDDLE OF NEXT  
WEEK AS A WEAKENING COLD FRONT APPROACHES THE REGION FROM THE  
NORTH.  
 
 
ADAMS  
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