534  
AXPZ20 KNHC 132201  
TWDEP  
 
TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL  
2205 UTC SAT SEP 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH  
2130 UTC.  
   
..TROPICAL WAVES
 
 
THE AXIS OF A TROPICAL WAVE IS ALONG 89W, FROM 02N NORTHWARD  
THROUGH WESTERN HONDURAS INTO THE YUCATAN PENINSULA. THE WAVE IS  
MOVING WESTWARD AROUND 15 TO 20 KT. CONVECTION ASSOCIATED WITH  
THIS WAVE IS DESCRIBED IN THE ITCZ/MONSOON TROUGH SECTION BELOW.  
   
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
 
 
THE MONSOON TROUGH AXIS EXTENDS FROM 08.5N78.5W TO 08N82W TO  
15N117W TO 13N140W. SCATTERED MODERATE TO ISOLATED STRONG  
CONVECTION IS NOTED FROM 06N TO 10N EAST OF 90W, FROM 07N TO 13N  
BETWEEN 93W AND 99W, FROM 08N TO 22N BETWEEN 105W AND 119W, AND  
FROM 10N TO 15N BETWEEN 121W AND 140W.  
   
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
 
 
RECENT SCATTEROMETER SATELLITE DATA SHOW FRESH TO STRONG SE TO  
NE WINDS AND MODERATE SEAS ARE OCCURRING OFF THE COAST OF JALISCO  
NEAR THE REMNANT LOW OF TROPICAL STORM MARIO, ANALYZED NEAR  
18.5N107.5W. ELSEWHERE, MODERATE TO FRESH N TO NE WINDS EXTEND  
THROUGH THE GULF OF TEHUANTEPEC AS HIGH PRESSURE BUILDS OVER  
EAST-CENTRAL MEXICO. OFFSHORE OF BAJA CALIFORNIA, THE PRESSURE  
GRADIENT BETWEEN A SURFACE TROUGH OVER NORTHWESTERN MEXICO INTO  
THE CENTRAL GULF OF CALIFORNIA AND HIGH PRESSURE TO THE WEST IS  
SUPPORTING MODERATE NW WINDS AND 5 TO 7 FT SEAS, AS NOTED ON  
RECENT SCATTEROMETER AND ALTIMETER DATA. GENTLE TO MODERATE WINDS  
AND 1 TO 3 FT SEAS PREVAIL IN THE GULF OF CALIFORNIA.  
 
FOR THE FORECAST, MODERATE TO LOCALLY FRESH WINDS ARE EXPECTED  
OFFSHORE OF WEST-CENTRAL MEXICO AND NEAR THE REVILLAGIGEDO  
ISLANDS THIS WEEKEND AS THE REMNANTS OF FORMER TROPICAL STORM  
MARIO SLOWLY DISSIPATE. ELSEWHERE, FRESH TO LOCALLY STRONG N TO  
NE WINDS WILL PULSE IN THE GULF OF TEHUANTEPEC TONIGHT INTO EARLY  
SUN. MODERATE TO OCCASIONALLY FRESH NE WINDS ARE EXPECTED  
THEREAFTER, WITH WINDS INCREASING TO STRONG SPEEDS BY THE MIDDLE  
OF NEXT WEEK. MODERATE TO FRESH NW WINDS OFFSHORE OF BAJA  
CALIFORNIA WILL OCCUR THROUGH TONIGHT BEFORE DIMINISHING SLIGHTLY  
SUN INTO NEXT WEEK. LOOKING AHEAD, AN AREA OF LOW PRESSURE  
LOCATED SOUTH OF THE BAJA CALIFORNIA PENINSULA IS EXPECTED TO  
ENCOUNTER ENVIRONMENTAL CONDITIONS CONDUCIVE FOR GRADUAL  
DEVELOPMENT, AND A TROPICAL DEPRESSION COULD FORM BY THE MIDDLE  
OF NEXT WEEK AS IT TRACKS SLOWLY WESTWARD. THERE IS A LOW CHANCE  
OF FORMATION WITHIN THE NEXT 48 HOURS, AND A MEDIUM CHANCE IN THE  
NEXT 7 DAYS. ELSEWHERE, AN AREA OF LOW PRESSURE COULD DEVELOP  
WELL OFFSHORE OF THE COAST OF SOUTHERN OR SOUTHWESTERN MEXICO  
EARLY NEXT WEEK. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE  
CONDUCIVE FOR GRADUAL DEVELOPMENT AS THE LOW TRACKS WESTWARD TO  
WEST-NORTHWESTWARD AROUND 10 TO 15 MPH. THERE IS A LOW CHANCE OF  
DEVELOPMENT WITHIN THE NEXT 7 DAYS.  
 
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,  
AND WITHIN 750 NM OF ECUADOR...  
 
MODERATE TO LOCALLY FRESH S WINDS ARE OCCURRING SOUTH OF THE  
MONSOON TROUGH, WITH GENTLE TO LOCALLY MODERATE WINDS NOTED TO  
THE NORTH, AS OBSERVED VIA A RECENT SCATTEROMETER PASS. SEAS OF  
5 TO 7 FT SEAS PREVAIL OVER THE REGIONAL WATERS, WITH SEAS TO 8  
FT NOTED SOUTH OF THE GALAPAGOS ISLANDS.  
 
FOR THE FORECAST, A LONG-PERIOD SOUTHERN HEMISPHERE SWELL WILL  
MOVE THROUGH THE CENTRAL AND SOUTH AMERICAN WATERS THIS WEEKEND,  
LEADING TO ROUGH SEAS OFFSHORE OF ECUADOR BY THIS EVENING, AND  
OFFSHORE OF COLOMBIA THROUGH COSTA RICA SUN INTO EARLY NEXT WEEK.  
SEAS WILL SLOWLY SUBSIDE REGION-WIDE INTO TUE, THOUGH ROUGH SEAS  
MAY PREVAIL BETWEEN THE GALAPAGOS ISLANDS AND ECUADOR THROUGH  
MIDWEEK. OTHERWISE, MODERATE TO OCCASIONALLY FRESH S TO SW WINDS  
WILL PREVAIL SOUTH OF THE MONSOON TROUGH. LOOKING AHEAD,  
OCCASIONAL MODERATE NE GAP WINDS WILL BE POSSIBLE IN THE GULF OF  
PAPAGAYO BY THE MIDDLE OF NEXT WEEK.  
   
..REMAINDER OF THE AREA
 
 
RIDGING DOMINATES THE EASTERN PACIFIC WATERS NORTH OF THE  
MONSOON TROUGH, WITH GENTLE TO LOCALLY MODERATE N TO NE WINDS  
FOUND NORTH OF 25N AND WEST OF 130W. A MODERATE PRESSURE GRADIENT  
BETWEEN THIS RIDGE AND THE MONSOON TROUGH IS SUPPORTING MODERATE  
TO FRESH NE WINDS FARTHER SOUTH AND TO THE WEST OF 115W, AS  
OBSERVED VIA SCATTEROMETER DATA. RECENT ALTIMETER DATA SHOW 5 TO  
7 FT SEAS IN THIS REGION, WITH LOCALLY ROUGH SEAS NOTED FROM 05N  
TO 10N WEST OF 135W. ELSEWHERE, A LONG-PERIOD SOUTHERN HEMISPHERE  
SWELL IS SUPPORTING 8 TO 9 FT SEAS SOUTH OF THE EQUATOR.  
MODERATE TO LOCALLY FRESH S TO SE WINDS AND 5 TO 7 FT SEAS  
PREVAIL ELSEWHERE SOUTH OF THE MONSOON TROUGH.  
 
FOR THE FORECAST, A LONG-PERIOD SOUTHERN HEMISPHERE SWELL WILL  
PROPAGATE NORTHWARD THIS WEEKEND, SUPPORTING ROUGH SEAS SOUTH OF  
05N BETWEEN 90W AND 120W BY TONIGHT, AND SOUTH OF 15N ON SUN.  
ROUGH SEAS WILL DIMINISH SOUTH OF 05N EARLY NEXT WEEK, WITH ROUGH  
SEAS PERSISTING FARTHER NORTH THROUGH THE MIDDLE OF NEXT WEEK.  
ELSEWHERE, FRESH TO LOCALLY STRONG WINDS ARE EXPECTED WITHIN 120  
NM ON BOTH SIDES OF THE MONSOON TROUGH AND ITCZ GENERALLY BETWEEN  
105W AND 130W SUN THROUGH EARLY NEXT WEEK. OTHERWISE, MODERATE  
TO LOCALLY FRESH WINDS ARE EXPECTED ELSEWHERE IN THE TRADE WIND  
WATERS.  
 

 
ADAMS  
 
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