273
AXPZ20 KNHC 200919
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0915 UTC.
..SPECIAL FEATURES
GULF OF TEHUANTEPEC GALE WARNING: THE PRESSURE GRADIENT BETWEEN A
1024 MB HIGH PRESSURE SYSTEM OVER THE EASTERN UNITED STATES AND
LOWER PRESSURES IN THE DEEP TROPICS RESULT IN FRESH TO NEAR GALE-
FORCE NORTHERLY WINDS ACROSS THE GULF OF TEHUANTEPEC. THIS WAS
CONFIRMED BY A RECENT SCATTEROMETER SATELLITE PASS. FREQUENT
GUSTS TO GALE FORCE ARE OCCURRING THROUGH LATE THIS MORNING. SEAS
ARE PEAKING AROUND 8-9 FT (2.5-3 M). FRESH TO STRONG WINDS WILL
PERSIST ACROSS THE AREA THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
GALE CONDITIONS WILL BE POSSIBLE, MAINLY AT NIGHT, MON THROUGH
WED AS HIGH PRESSURE DEVELOPS OVER THE EASTERN SLOPES OF THE
SIERRA MADRE MOUNTAINS IN MEXICO. ROUGH SEAS ARE ALSO LIKELY TO
DEVELOP WITH THE STRONGEST WINDS.
PLEASE READ THE LATEST HIGH SEAS FORECAST ISSUED BY THE NATIONAL
HURRICANE CENTER AT WEBSITE:
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIASFEP2.SHTML FOR MORE
INFORMATION.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N98W. THE ITCZ STRETCHES
FROM 09N98W TO 10N117W TO BEYOND 06N140W. SCATTERED MODERATE
CONVECTION IS OBSERVED FROM 07N TO 13N AND BETWEEN 113W AND 128W.
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
HIGH PRESSURE NORTH OF THE GULF OF TEHUANTEPEC SUSTAINS FRESH TO
NEAR GALE-FORCE NORTHERLY WINDS, ALONG WITH FREQUENT GUSTS TO
GALE FORCE AND SEAS TO 8-9 FT, ACROSS THE TEHUANTEPEC BASIN.
ELSEWHERE, A 1022 MB SUBTROPICAL RIDGE NEAR 30N130W EXTENDS A
RIDGE TO THE REVILLAGIGEDO ISLANDS. MODERATE NORTHERLY WINDS AND
MODERATE SEAS ARE PRESENT WEST OF GUADALUPE ISLANDS, WHILE LIGHT
TO GENTLE WINDS AND MODERATE SEAS PREVAIL IN THE REST OF THE
BAJA CALIFORNIA OFFSHORE WATERS. MODERATE NORTHERLY WINDS AND
SEAS OF 2-4 FT ARE NOTED OFF CABO CORRIENTES. IN THE REST OF THE
MEXICAN OFFSHORE WATERS, LIGHT TO GENTLE WINDS AND SLIGHT TO
MODERATE SEAS ARE EVIDENT.
FOR THE FORECAST, HIGH PRESSURE NORTH OF THE GULF OF TEHUANTEPEC
WILL SUPPORT FRESH TO NEAR GALE-FORCE NORTHERLY WINDS AND
MODERATE TO LOCALLY ROUGH SEAS OVER THE NEXT SEVERAL DAYS. WINDS
MAY PULSE TO GALE-FORCE AT NIGHT MON THROUGH WED. ELSEWHERE, FOR
MOST WATERS, A RELATIVELY WEAK PRESSURE GRADIENT WILL LEAD TO
MODERATE OR WEAKER WINDS AND SEAS INTO THE START OF NEXT WEEK.
LOOKING AHEAD, A COLD FRONT WILL APPROACH THE OFFSHORE WATERS OF
BAJA CALIFORNIA NORTE BY MIDWEEK POSSIBLY PRODUCING FRESH TO
STRONG SOUTHERLY WINDS AND ROUGH SEAS.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
A 1024 MB HIGH PRESSURE SYSTEM OVER THE EASTERN UNITED STATES
SUPPORTS FRESH TO LOCALLY STRONG EASTERLY GAP WINDS IN THE GULF
OF PAPAGAYO, EXTENDING DOWNSTREAM TO 90W. SEAS IN THESE WATERS
ARE 4-7 FT. FARTHER EAST, MODERATE TO LOCALLY FRESH NORTHERLY
WINDS AND SEAS OF 2-4 FT ARE OCCURRING IN THE GULF OF PANAMA.
ELSEWHERE, MODERATE OR LIGHTER WINDS AND MODERATE SEAS PREVAIL.
FOR THE FORECAST, BUILDING HIGH PRESSURE NORTH OF THE AREA WILL
SUPPORT FRESH TO STRONG NE TO E WINDS, MAINLY DURING LATE
NIGHT/EARLY MORNING HOURS ACROSS THE GULF OF PAPAGAYO OVER THE
NEXT SEVERAL DAYS. IN THE GULF OF PANAMA, MAINLY GENTLE TO
MODERATE N WINDS ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
ELSEWHERE, A WEAK PRESSURE GRADIENT WILL CONTINUE TO ONLY FORCE
MODERATE OR WEAKER WINDS WITH SLIGHT TO MODERATE SEAS ACROSS THE
REMAINDER OF THE FORECAST WATERS INTO THE START OF NEXT WEEK.
..REMAINDER OF THE AREA
A 1022 MB SUBTROPICAL RIDGE CENTERED NEAR 30N130W DOMINATES THE
REMAINDER OF THE TROPICAL EASTERN PACIFIC. A RECENT SCATTEROMETER
SATELLITE PASS SHOWED MODERATE TO LOCALLY FRESH NE-E WINDS OVER
MUCH OF THE BASIN WEST OF 120W AND NORTH OF THE ITCZ. SEAS IN
THESE WATERS ARE 5-8 FT. EAST OF 120W AND NORTH OF THE ITCZ AND
MONSOON TROUGH, MODERATE EASTERLY BREEZES AND SEAS OF 3-5 FT ARE
PREVALENT. SOUTH OF THE MONSOON TROUGH AND ITCZ AND WEST OF
100W, MODERATE TO LOCALLY FRESH SOUTHERLY WINDS AND SEAS OF 5-8
FT PREVAIL. ELSEWHERE, MODERATE OR WEAKER WINDS AND MODERATE SEAS
ARE EVIDENT.
FOR THE FORECAST, HIGH PRESSURE WILL REMAIN IN CONTROL OF THE
WEATHER PATTERN ACROSS THE WATERS N OF ITCZ/MONSOON TROUGH AND W
OF 110W THROUGH AT LEAST SUN, WITH LITTLE CHANGE IN WINDS AND
SEAS. STARTING SUN NIGHT, A SURFACE TROUGH IS EXPECTED TO FORM
ALONG THE ITCZ NEAR 120W ENHANCING DEEP CONVECTION AND STRENGTHENING
WINDS FOR A COUPLE OF DAYS. AT THE SAME TIME, A COLD FRONT WILL
REACH THE NW WATERS NEAR 30N140W, BRINGING FRESH TO STRONG SW
WINDS AHEAD OF THE FRONT AND FRESH TO STRONG N WINDS BEHIND THE
FRONT EARLY NEXT WEEK. A SWELL EVENT WILL FOLLOW THE FRONT, BUILDING
SEAS TO 8-12 FT BEGINNING LATE ON MON. BY MIDWEEK, A BROAD LOW
PRESSURE NORTH OF THE AREA WILL PRODUCE STRONG TO NEAR GALE-
FORCE WESTERLY WINDS AND ROUGH TO VERY ROUGH SEAS NORTH OF 23N.
DELGADO
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