073
AXPZ20 KNHC 212057
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 21 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
2030 UTC.
..TROPICAL WAVES
A TROPICAL WAVE, WITH AXIS ALONG 103W, LOCATED A FEW HUNDRED
MILES SOUTH OF THE COAST OF SOUTHERN MEXICO IS PRODUCING
DISORGANIZED SHOWERS AND THUNDERSTORMS FROM THE OFFSHORE WATERS
OF WESTERN OAXACA TO OFFSHORE OF COLIMA. RECENT SATELLITE
SCATTEROMETER DATA SHOWED THAT FRESH TO LOCALLY STRONG EASTERLY
WINDS ACCOMPANIED THIS WAVES ACROSS THE OFFSHORE WATERS OF
OAXACA AND GUERRERO, WITH SEAS OF 5 TO 7 FT. ENVIRONMENTAL
CONDITIONS APPEAR CONDUCIVE FOR GRADUAL DEVELOPMENT OF THIS
SYSTEM, AND A TROPICAL DEPRESSION IS LIKELY TO FORM LATE THIS
WEEK OR THIS WEEKEND AS IT MOVES GENERALLY WESTWARD AT 10 TO 15
KT, REMAINING WELL OFFSHORE OF MEXICO. CURRENTLY THIS SYSTEM HAS
A LOW CHANCE OF TROPICAL CYCLONE FORMATION THROUGH 48 HOURS, AND
A HIGH CHANCE THROUGH 7 DAYS. PLEASE, REFER TO THE LATEST NHC
TROPICAL WEATHER OUTLOOK AT WWW.HURRICANES.GOV FOR MORE DETAILS.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
THE MONSOON TROUGH EXTENDS FROM 12.5N73W TO 09N85W TO 11.5N100W
TO LOW PRES 1013 MB NEAR 12.5N114W TO 11N117W. THE ITCZ EXTENDS
FROM 11N117W TO 09N125W TO 10N130W, THEN RESUMES FROM 10N133W TO
BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION
IS FOUND FROM 02.5N TO 07N E OF 83W TO THE COAST OF COLOMBIA,
FROM 06.5N TO 12N BETWEEN 84W AND 94W, FROM 08.5N TO 15N BETWEEN
98W AND 113W, AND FROM 07.5N TO 13.5N BETWEEN 128W AND 137W.
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
A WEAK RIDGE CONTINUES ACROSS THE OFFSHORE FORECAST WATERS OF
BAJA CALIFORNIA, CENTERED ON 1020 MB HIGH PRESSURE LOCATED NEAR
23N122W. RECENT SATELLITE SCATTEROMETER DATA SHOWED THAT THIS
PATTERN SUPPORTS GENTLE TO MODERATE NW TO N WINDS ACROSS THE BAJA
CALIFORNIA WATERS, AS WELL AS THROUGH THE FULL LENGTH OF THE
GULF OF CALIFORNIA. SEAS ACROSS THE OFFSHORE WATERS ARE 5 TO 7 FT
IN NW SWELL, EXCEPT 7 TO 8 FT IN NEW NW SWELL ACROSS THE OUTER
WATER OF BAJA NORTE, AND 1 TO 3 FT ACROSS THE GULF WATERS.
ELSEWHERE ACROSS THE MEXICAN OFFSHORE WATERS FROM CABO CORRIENTES
TO PUERTO ANGEL, LIGHT TO GENTLE WINDS AND MODERATE SEAS TO 5 FT
PREVAIL. FRESH TO STRONG N TO NE GAP WINDS ARE BLOWING ACROSS
THE GULF OF TEHUANTEPEC AND DOWNWIND SOUTHWESTWARD TO ABOUT 14N,
THEN BECOME FRESH EASTERLY WINDS THAT FOLLOW INTO THE TROPICAL
WAVE TO ALONG 102W. SEAS ARE 6 TO 7 FT WITHIN THESE WINDS.
SCATTERED SHOWERS AND THUNDERSTORMS ACCOMPANY THE TROPICAL WAVE
ACROSS THE WATERS 90 NM AND GREATER OFFSHORE.
FOR THE FORECAST, BUILDING HIGH PRESSURE ACROSS THE EASTERN SLOPES
OF THE SIERRA MADRE MOUNTAINS IN MEXICO WILL COMBINE WITH BROAD
LOW PRESSURE ACROSS THE SW CARIBBEAN TO MAINTAIN AN EARLY SEASON
GAP WIND EVENT ACROSS THE TEHUANTEPEC REGION THROUGH FRI MORNING.
FRESH TO STRONG NORTHERLY WINDS, REACHING NEAR 30 KT, AND
MODERATE TO ROUGH SEAS TO NEAR 7 OR 8 FT, ARE EXPECTED WITH THIS
EVENT DURING THE OVERNIGHT AND EARLY MORNING HOURS MOST OF THE
WEEK. NW SWELL WILL PROPAGATE ACROSS THE OFFSHORE WATERS OF BAJA
CALIFORNIA THROUGH THE FORECAST PERIOD, SUPPORTING MODERATE TO
ROUGH SEAS, AND ARE EXPECTED TO PEAK WED THROUGH THU. WINDS WILL
FRESHEN ACROSS THE NEAR AND OFFSHORE WATERS OF BAJA CALIFORNIA
BY WED MORNING, AND CONTINUE THROUGH THU EVENING AS THE PRESSURE
GRADIENT TIGHTENS SOME ACROSS THE AREA BETWEEN THE HIGH PRESSURE
RIDGE TO THE WEST AND LOWER PRESSURES OVER NORTH-CENTRAL MEXICO.
LOOKING AHEAD, A TROPICAL WAVE LOCATED A FEW HUNDRED MILES SOUTH
OF THE COAST OF SOUTHERN MEXICO OFFSHORE OF GUERRERO HAS THE
POTENTIAL FOR TROPICAL CYCLONE FORMATION. PLEASE, SEE THE
TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION IS AFFECTING
THE OFFSHORE WATERS OF CENTRAL AMERICA, ROUGHLY FROM COSTA RICA
TO OFFSHORE OF THE GULF OF FONSECA, AS WELL AS OFFSHORE OF
SOUTHWESTERN COLOMBIA. RECENT SATELLITE SCATTEROMETER DATA
INDICATED GENTLE TO MODERATE SW WINDS SOUTH OF THE MONSOON
TROUGH, AND MODERATE TO LOCALLY FRESH N TO NE WINDS TO THE NORTH
OF IT, BETWEEN PAPAGAYO AND EL SALVADOR. MODERATE SEAS 6 FT OR
LESS PREVAIL IN THESE WATERS IN MIXED S AND SW SWELL, EXCEPT 3 FT
OR LESS IN THE LEE OF THE GALAPAGOS ISLANDS.
FOR THE FORECAST, MODERATE TO FRESH NE GAP WINDS ACROSS THE
PAPAGAYO REGION TODAY WILL CONTINUE OVERNIGHT THEN GRADUALLY
DIMINISH ON WED, AND BECOME VARIABLE THROUGH THE END OF THE WEEK.
LITTLE CHANGE IN THE WEATHER PATTERN IS FORECAST ELSEWHERE, WITH
MODERATE S TO SW WINDS AND MODERATE SEAS EXPECTED SOUTH OF THE
MONSOON TROUGH THROUGH THE FORECAST PERIOD.
..REMAINDER OF THE AREA
HIGH PRESSURE N OF AREA HAS COLLAPSED THIS AFTERNOON, BUT STILL EXTENDS
A BROAD RIDGE TO THE SOUTH AND SOUTHEAST, AND COVERS THE
FORECAST WATERS N OF 15N AND W OF 125W. FRESH TO STRONG WINDS
ARE NOTED WITHIN 180 NM ACOSS THE N SEMICIRCLE AND 90 NM ACROSS
THE SE QUADRANT OF A LOW PRESSURE CENTER LOCATED ALONG THE
MONSOON TROUGH NEAR 11.5N131W. SEAS THERE ARE 7 TO 9 FT IN NW
SWELL. MODERATE TO LOCALLY FRESH WINDS ARE FOUND ELSEWHERE FROM
10N TO 21N AND W OF 120W. MODERATE SEAS OF 5 TO 7 FT ARE WITHIN
THESE WINDS, EXCEPT NEAR THE LOW CENTER DESCRIBED ABOVE. MODERATE
NE TO E WINDS AND ROUGH SEAS IN NW SWELL DOMINATE THE NW CORNER
OF THE FORECAST REGION, PARTICULARLY N OF 27N W OF 125W.
MODERATE TO LOCALLY FRESH SOUTHERLY WINDS AND MODERATE SEAS ARE
FOUND SOUTH OF THE MONSOON TROUGH W OF 110W. ELSEWHERE, MODERATE
OR WEAKER WINDS AND MODERATE SEAS ARE PREVALENT.
FOR THE FORECAST, STRONG HIGH PRESSURE NORTH OF THE HAWAIIAN
ISLANDS WILL BUILD EASTWARD, TO THE SOUTH OF A FRONTAL SYSTEM,
AND INTO THE NORTHERN WATERS THROUGH FRI, AND REINFORCE THE
CURRENT RIDGE DOMINATING THE AREA WATERS. THE PRESSURE GRADIENT
BETWEEN THE RIDGE AND A WESTWARD MOVING LOW PRESSURE CENTER
ALONG THE MONSOON TROUGH NEAR 131W WILL SUPPORT FRESH TO STRONG
WINDS AND ROUGH SEAS NEAR THE LOW CENTER THROUGH AT LEAST THU
MORNING. THE LOW IS FORECAST TO CROSS 140W BY THU AFTERNOON WHILE
IT OPENS UP INTO A TROUGH.
STRIPLING
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