004
AXPZ20 KNHC 211524
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.
..TROPICAL WAVES
A TROPICAL WAVE, WITH AXIS ALONG 102W, LOCATED A FEW HUNDRED
MILES SOUTH OF THE COAST OF SOUTHERN MEXICO IS PRODUCING
DISORGANIZED SHOWERS AND THUNDERSTORMS FROM THE OFFSHORE WATERS
OF OAXACA TO OFFSHORE OF COLIMA. OVERNIGHT SATELLITE
SCATTEROMETER DATA SHOWED THAT WINDS SURROUNDING THIS SYSTEM WERE
15 KT AND LESS, WITH SEAS OF 5 TO 6 FT. ENVIRONMENTAL CONDITIONS
APPEAR CONDUCIVE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM, AND A
TROPICAL DEPRESSION IS LIKELY TO FORM LATE THIS WEEK 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 11N74.5W TO 10N80W TO 13N94W TO
12N102W TO 13N113W TO 09N118W. THE ITCZ EXTENDS FROM 09N118W TO
11N128W, THEN RESUMES FROM 09N131W TO BEYOND 08N140W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION CAN BE FOUND FROM 02.5N TO
08N E OF 82W TO THE COAST OF COLOMBIA, FROM 06.5N TO 13.5N
BETWEEN 83W AND 94W, FROM 08.5N TO 15.5N BETWEEN 97W AND 110W,
AND FROM 08N TO 13N BETWEEN 127W AND 136W.
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
A WEAK RIDGE DOMINATES THE OFFSHORE FORECAST WATERS OF BAJA
CALIFORNIA, CENTERED ON 1018 MB HIGH PRESSURE LOCATED NEAR
25N122W. 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, AND 2 TO 4 FT ACROSS THE GULF WATERS. ELSEWHERE
ACROSS THE MEXICAN OFFSHORE WATERS FROM CABO CORRIENTES TO PUERTO
ANGEL, LIGHT AND VARIABLE 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.
SEAS ARE 6 TO 7 FT WITHIN THESE WINDS.
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 THU NIGHT.
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. LONG PERIOD NW SWELL WILL PROPAGATE ACROSS THE OFFSHORE
WATERS OF BAJA CALIFORNIA THROUGH THE FORECAST PERIOD, SUPPORTING
MODERATE TO ROUGH SEAS. WINDS WILL FRESHEN IN THE 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 FOR
MORE DETAILS.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
SMALL CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION IS
AFFECTING THE OFFSHORE WATERS OF CENTRAL AMERICA, ROUGHLY FROM
NORTHERN COSTA RICA TO GUATEMALA, WHILE A LARGER CLUSTER IS
OFFSHORE OF SOUTHWESTERN COLOMBIA. RECENT SATELLITE
SCATTEROMETER DATA INDICATED GENTLE TO MODERATE SW WINDS SOUTH OF
THE MONSOON TROUGH, AND LIGHT TO GENTLE WINDS TO THE NORTH OF
IT. MODERATE SEAS LESS THAN 6 FT 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, FRESH NE GAP WINDS ARE EXPECTED ACROSS THE
PAPAGAYO REGION TODAY, INCREASING TO STRONG SPEEDS BY THIS
EVENING, THEN GRADUALLY DIMINISHING ON WED. LITTLE CHANGE IN THE
WEATHER PATTERN IS FORECAST ELSEWHERE. MODERATE S TO SW WINDS
AND MODERATE SEAS ARE EXPECTED SOUTH OF THE MONSOON TROUGH
THROUGH THE FORECAST PERIOD.
..REMAINDER OF THE AREA
A 1025 MB HIGH PRESSURE IS LOCATED N OF AREA NEAR 39N137W AND EXTENDS
A BROAD RIDGE TO THE SOUTH AND SOUTHEAST, AND COVERS THE
FORECAST WATERS N OF 15N AND W OF 120W. FRESH TO STRONG WINDS
ARE NOTED WITHIN 120 NM N SEMICIRCLE AND 90 SE QUADRANT OF A LOW
PRESSURE LOCATED ALONG THE MONSOON TROUGH NEAR 11.5N129.5W. SEAS
THERE ARE 7 TO 9 FT. MODERATE TO LOCALLY FRESH WINDS ARE FOUND
ELSEWHERE FROM 10N TO 19N AND W OF 125W. MODERATE SEAS OF 5 TO 7
FT ARE WITHIN THESE WINDS. MODERATE TO LOCALLY FRESH NE TO E
WINDS AND ROUGH SEAS IN NW SWELL DOMINATE THE NW CORNER OF THE
FORECAST REGION, PARTICULARLY N OF 28N 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, THE RIDGE WILL REMAIN IN CONTROL OF THE WEATHER
PATTERN ACROSS THE N WATERS, AS IT SETTLES TOWARD THE SW AND
WEAKENS. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND A WESTWARD-
MOVING LOW PRESSURE CENTER ALONG THE MONSOON TROUGH NEAR 129W
WILL SUPPORT FRESH TO STRONG WINDS AND ROUGH SEAS NEAR THE LOW
CENTER THROUGH AT LEAST THE MIDDLE PORTION OF THIS WEEK. THE LOW
IS FORECAST TO CROSS 140W ON THU WHILE IT OPENS UP INTO A TROUGH.
STRIPLING
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