Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Dec 19 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to to 09N95W to 09N110W. The ITCZ continues from 09N110W to beyond 07N140W. Scattered moderate convection is noted from 07N to 10N between 83W and 106W and from 07N to 11N between 115W and 134W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore forecast waters of Baja California supporting moderate to locally fresh NW to N winds N of Cabo San Lazaro with moderate seas in NW swell. Elsewhere across the Mexican offshore waters, including the Gulf of California, light to gentle winds prevail with slight to moderate seas primarily in NW swell. For the forecast, for most waters, a relatively weak pressure gradient will lead to moderate or weaker winds and seas into the start of next week. High pressure building through NE Mexico will lead to increasing gap winds in Gulf of Tehuantepec by this afternoon, with winds becoming strong tonight. Fresh to strong gap winds will prevail in this area through the weekend, then increase to near gale-force Sun night through the middle of next week. Rough seas are also likely to develop early next week where the strongest winds occur. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to locally fresh gap winds are noted in the Gulf of Papagayo by latest scatterometer data. Otherwise, winds across the forecast waters are mainly gentle. Seas are 3 to 5 ft. For the forecast, a weak pressure gradient will continue to only force moderate or weaker winds across most forecast waters into the start of next week. Building high pressure over Central America will drive fresh to locally strong NE winds mainly during late night/early morning hours across the Papagayo region from this evening through mid next week. Elsewhere, winds and seas will be quiescent. ...REMAINDER OF THE AREA... A 1021 mb high centered near 31N130W combined with lower pressure over the ITCZ is forcing moderate to locally fresh NE to E trades north of the ITCZ and W of 120W. South of the ITCZ/ Monsoon Trough, winds are gentle to moderate with seas of 4 to 7 ft. For the forecast, little change is expected through Sun. 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 moderate to fresh SW ahead of the front and fresh N winds behind the front early next week. A swell event will follow the front, building seas to 8 to 12 ft beginning on Mon.