Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Dec 23 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 0905 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure north of the area and the eastern north Pacific monsoon trough will sustain fresh to near gale-force northerly winds and moderate to locally rough seas through the end of the week. Winds will pulse to gale-force at night through Wed night. A recent scatterometer satellite pass showed a large area of strong to gale-force winds, peaking at 34 kt. Seas will peak around 11 ft (3.5 M) with the strongest winds. Latest altimeter pass over the eastern portion of the Gulf of Tehuantepec captured seas to 9 ft (3 M). Conditions will improve by the weekend. Northern Waters Gale Warning: A cold front extends southwestward from a strengthening 1008 mb low pressure near 28N133W to 22N140W, while a stationary front extends from the low to 30N131W. Scattered showers and isolated thunderstorms are noted north of the low. The pressure gradient between this area of low pressure and high pressure NW of the area will produce strong to gale-force winds in the northern waters, mainly north of 26N, today through tonight. A recent scatterometer satellite pass indicate that strong to gale-force N-NW winds are occurring west of the low. Winds will decrease below gale-force in the overnight hours as the low pressure moves farther north of our waters. Seas will build to near 15 ft (4.5 M) with this system tonight. A second gale force low north of the area will generate a new set of large NW swell, which will reinforce these very rough seas. Combined seas of 12 to 18 ft (3.5-5.5 M) will spread over the northern waters, covering much of the waters N of 24N and W of 125W by Thu before starting to subside. This low will also produce strong to near gale-force westerly winds across the area described. Winds could reach gale speeds in the far NW waters Wed into Wed night. Winds will diminish below strong speeds Thu night. Please read the latest High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 08N85W and to 06N94W. The ITCZ stretches from 06N94W to 10N115W. Surface trough along 122W. The ITCZ continues from 09N126W to beyond 09N140W. Scattered moderate convection is observed from 07N to 18N and between 105W and 120W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details on a Gale Warning in the Gulf of Tehuantepec. Aside from the Gulf of Tehuantepec, a 1017 mb high pressure system near 25N118W dominates the remainder of the Mexican offshore waters. Moderate to locally fresh easterly winds and moderate seas are noted in far offshore waters of Oaxaca and Guerrero. Meanwhile, light to gentle winds and slight to moderate seas prevail elsewhere. For the forecast, aside from the Gulf of Tehuantepec, a cold front will approach the offshore waters of Baja California, supporting fresh to strong southerly winds tonight into Wed. Northwest swell will propagate into the waters north of Punta Eugenia tonight into Wed. A reinforcing swell will spread rough seas across the offshore waters of the Baja California peninsula by the end of the week into the weekend. Fresh to strong southerly winds may develop in the northern Gulf of California Wed night into Thu. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The strong subtropical ridge centered over the eastern United States and the western Atlantic forces fresh to locally strong easterly trade winds and moderate seas across the Gulf of Papagayo, extending downstream to 90W. Farther east, moderate northerly winds and seas of 2-4 ft are found in the Gulf of Panama. In the remainder of the basin, moderate or lighter winds and moderate seas are prevalent. For the forecast, the pressure gradient between high pressure north of the area and the eastern north Pacific monsoon trough will support pulsing fresh to strong northeast to east gap winds in the Gulf of Papagayo over the next several days. Mainly gentle to moderate north winds are expected in the Gulf of Panama during the period, occasionally reaching fresh speeds at night. Moderate or lighter winds and slight to moderate seas are expected elsewhere through the period. ...REMAINDER OF THE AREA... Please read the Special Features section for more details on the Gale Warning in the northern waters. Aside from the strengthening area of low pressure in the far NW waters that is producing a large area of strong to gale-force N winds and rough seas, the remainder of the eastern tropical Pacific is under the influence of a weak pressure gradient. Moderate to locally fresh easterly winds are present north of the monsoon trough and ITCZ and east of 125W. Seas in these waters are 5-7 ft. Elsewhere, moderate or weaker winds and moderate seas are prevalent. For the forecast, low pressure over the far NW waters will continue to strengthen and shift northeastward today, dragging a cold front across the northern waters. Tight gradient between the low and 1041 mb high pressure NW of the area will produce strong to gale- force NW-N winds north of about 26N today through tonight. Rough to very rough seas are expected to build with these winds. This system will shift N of the area with winds over the discussion waters associated with this feature diminishing. A second gale force low will develop north of the area with a broad wind field bringing strong to possible gale force winds over the northern discussion waters by midweek. A set of large NW swell generated from this feature will reinforce the rough seas generated from the first low. Meanwhile, the surface trough in the trade waters will continue to enhance convection with locally higher winds and seas before diminishing Wed.