326  
AXPZ20 KNHC 182240  
TWDEP  
 
TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL  
2205 UTC MON MAY 18 2026  
 
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  
2100 UTC.  
   
..SPECIAL FEATURES  
 
SIGNIFICANT SWELL EVENT WEST OF BAJA CALIFORNIA NORTE:  
LARGE, LONG-PERIOD NW SWELL IS MAINTAINING VERY ROUGH SEAS OF 12  
TO 13 FT, NORTH OF 27N BETWEEN 118W AND 127W, INCLUDING WATERS  
JUST WEST OF GUADALUPE ISLAND. THIS SWELL WILL CONTINUE TO DECAY  
AND RETREAT NORTHWARD THROUGH LATE TUE, WHICH SHOULD ALLOW SEAS  
TO SUBSIDE BELOW 12 FT AFTER MIDNIGHT TONIGHT.  
 
PLEASE REFER TO THE LATEST HIGH SEAS AND OFFSHORE WATERS  
FORECASTS ISSUED BY THE NATIONAL HURRICANE CENTER AT WEBSITES:  
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFEP2.SHTML AND  
HTTPS://WWW.NHC.NOAA.GOV/MARINE/OFFSHORES_EASTPAC.PHP FOR MORE  
DETAILS.  
   
..TROPICAL WAVES  
 
A TROPICAL WAVE IS NEAR 81W FROM THE WESTERN CARIBBEAN SEA  
SOUTHWARD ACROSS WESTERN PANAMA INTO THE EASTERN PACIFIC, AND  
MOVING WEST AT 5 TO 10 KT. IT IS ENHANCING CONVECTION NEAR THE  
MONSOON TROUGH DESCRIBED IN THE SECTION BELOW.  
   
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH  
 
A MONSOON TROUGH EXTENDS WEST-SOUTHWESTWARD FROM CENTRAL COSTA  
RICA TO 07N91W. AN ITCZ CONTINUES WESTWARD FROM 07N91W TO  
07N120W TO BEYOND 07N140W. SCATTERED MODERATE TO ISOLATED STRONG  
CONVECTION IS ACTIVE NEAR AND SOUTH OF THE MONSOON TROUGH FROM  
02N TO 11N EAST OF 88W, INCLUDING OFFSHORE WATERS OF COSTA RICA,  
PANAMA AND COLOMBIA. SIMILAR CONVECTION IS PRESENT NEAR THE ITCZ  
FROM 05N TO 12N BETWEEN 93W AND 117W. NUMEROUS MODERATE TO  
SCATTERED STRONG CONVECTION IS NOTED NEAR THE WESTERN PORTION OF  
THE ITCZ FROM 03N TO 11N WEST OF 118W.  
   
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO  
 
PLEASE READ THE SPECIAL FEATURES SECTION ABOVE REGARDING  
SIGNIFICANT NW SWELL.  
 
A BROAD SURFACE RIDGE HAS SHIFTED FARTHER WEST TO NEAR 130W THIS  
EVENING, WHICH ALLOWS NW TO N WINDS NEAR BAJA CALIFORNIA AND THE  
REVILLAGIGEDO ISLANDS TO BECOME GENTLE TO MODERATE. RESIDUAL  
LARGE, LONG-PEROID NW SWELL IS KEEPING SEAS AT 10 TO 13 FT WEST  
OF BAJA NORTE, AT 7 TO 10 FT WEST OF BAJA SUR, AND AT 5 TO 7 FT  
NEAR THE REVILLAGIGEDO ISLANDS. GENTLE TO MODERATE SE TO SW TO  
NW WINDS WITH 2 TO 4 FT SEAS DOMINATE THE GULF OF CALIFORNIA.  
LIGHT TO GENTLE WINDS AND SEAS OF 4 TO 5 FT IN MIXED MODERATE  
SWELL PREVAIL FOR THE CENTRAL AND SOUTHERN MEXICO OFFSHORE  
WATERS, EXCEPT AT THE FAR SOUTHERN WATERS OFF CHIAPAS STATE,  
WHERE MODERATE E WINDS PERSIST.  
 
FOR THE FORECAST, RESIDUAL LARGE, LONG-PERIOD NW SWELL WILL  
MAINTAIN 10 TO 12 FT SEAS OFF BAJA NORTE UNTIL MIDNIGHT TONIGHT,  
THEN SUBSIDE TO BETWEEN 6 AND 8 FT BY TUE AFTERNOON. SEAS OF 8 TO  
11 FT NEAR BAJA SUR WILL ALSO DROP TO BETWEEN 6 AND 8 FT BY TUE  
AFTERNOON. WINDS NEAR BAJA CALIFORNIA AND THE REVILLAGIGEDO  
ISLANDS, AND IN THE GULF OF CALIFORNIA WILL BECOME MOSTLY GENTLE  
THIS EVENING, AND STAY THIS WAY MOST OF THIS WEEK. THE ONLY  
EXCEPTION WILL BE MODERATE WITH LOCALLY FRESH NW WINDS OFF CABO  
SAN LUCAS IN THE NIGHT-TIME AND EARLY MORNING HOURS.  
 
....OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,  
AND WITHIN 750 NM OF ECUADOR...  
 
FRESH WITH LOCALLY STRONG NE TO E GAP WINDS AND SEAS OF 6 TO 8 FT  
ARE PERSISTING IN THE WATERS OFF THE PAPAGAYO REGION. FRESH E WINDS  
AND 5 TO 6 FT SEAS ARE SEEN FARTHER DOWNSTREAM ACROSS THE SOUTHERN  
OFFSHORE WATERS OF GUATEMALA AND EL SALVADOR. OTHERWISE, MAINLY  
GENTLE WINDS AND SEAS AT 2 TO 4 FT ARE SEEN FOR THE REST OF THE  
CENTRAL AMERICA OFFSHORE WATERS. GENTLE TO MODERATE SE TO SW  
WINDS WITH 4 TO 5 FT SEAS IN MODERATE SOUTHERLY SWELL PREVAIL OFF  
COLOMBIA AND ECUADOR, AND NEAR THE GALAPAGOS ISLANDS. REFER TO  
THE INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH SECTION ABOVE  
FOR CONVECTION IN THE REGION.  
 
FOR THE FORECAST, FRESH EASTERLY GAP WINDS IN THE PAPAGAYO REGION  
WILL PULSE TO STRONG DURING THE NIGHT-TIME HOURS THROUGH WED  
NIGHT. ELSEWHERE, GENTLE TO MODERATE WINDS ALONG WITH MODERATE  
SEAS IN SOUTHERLY SWELL ARE EXPECTED THROUGH MOST OF THIS WEEK.  
SCATTERED HEAVY SHOWERS AND ISOLATED THUNDERSTORMS WILL LINGER IN  
THE OFFSHORE WATERS OF COSTA RICA, PANAMA AND COLOMBIA THROUGH  
TONIGHT.  
   
..REMAINDER OF THE AREA  
 
A BROAD SURFACE RIDGE EXTENDS SOUTHWESTWARD FROM A 1034 MB HIGH  
NEAR 38N140W ACROSS 30N136W TO NEAR THE REVILLAGIGEDO ISLANDS.  
THIS FEATURE IS SUPPORTING MODERATE TO FRESH N TO NE WINDS NORTH  
OF THE ITCZ WEST OF 120W. UNDER LONG-PERIOD, LARGE TO MODERATE NW  
SWELL, SEAS IN THIS AREA RANGE FROM 7 TO 13 FT, WITH THE HIGHEST  
NEAR 29N123W. FOR THE WATERS NORTH OF THE ITCZ EAST OF 120W,  
GENTLE TO MODERATE NNE TO E WINDS WITH 5 TO 8 FT SEAS IN MIXED  
MODERATE SWELLS EXIST. GENTLE TO MODERATE SE TO E WINDS AND SEAS  
AT 5 TO 8 FT IN MIXED MODERATE SWELLS PREVAIL SOUTH OF THE ITCZ.  
 
FOR THE FORECAST, THE AFOREMENTIONED RIDGE WILL CONTINUE TO  
GRADUALLY WEAKEN WHILE SHIFTING WESTWARD THROUGH MIDWEEK. THIS  
WILL ALLOW WINDS AND SEAS NORTH OF THE ITCZ TO STEADILY SUBSIDE  
FROM EAST TO WEST THROUGH MIDWEEK, BECOMING GENTLE TO MODERATE  
WINDS WITH 6 TO 8 FT SEAS BY THU. WINDS SOUTH OF THE ITCZ WILL  
ALSO BECOMING GENTLE BY THU WITH SEAS STAYING AT 5 TO 7 FT IN  
MIXED SWELLS.  
 
 
 
CHAN  
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