Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Dec 17 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 09N103W. The ITCZ continues from that point to 10N126W to beyond 07N140W. Scattered moderate convection is noted from 06N to 09N between 85W and 92W, and from 06N to 12N between 110W and 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1026 mb high center is analyzed just N of the area near 32N132W. Its associated ridge extends to near the Revillagigedo Islands. The related pressure gradient is allowing for gentle to moderate northwest to north winds and slight to moderate seas over the Mexican offshore waters N of 20N including the Gulf of California. Light and variable winds and slight seas prevail elsewhere from 12N to 20N outside of the Tehuantepec area. In the region of the Gulf of Tehuantepec, winds have diminished below gale-force but are fresh to near gale and rough to very rough residual seas. For the forecast, fresh to strong N-NE winds and rough seas in the Gulf of Tehuantepec will persist into early Wed. These conditions may return by the end of the week into next weekend. Elsewhere, gentle to moderate winds and moderate seas will prevail through the middle of the week. Fresh to strong northerly winds and rough seas will develop mainly just beyond the offshore waters of Baja California Norte Wed through Thu. Moderate to fresh winds will pulse near Cabo Corrientes tonight through Wed night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast winds prevail in the Gulf of Papagayo region as high pressure builds in N of the Caribbean with lower pressures along the monsoon trough over southern Costa Rica and Panama. Light to gentle winds and moderate seas are elsewhere N of 07N, except rough seas well offshore Guatemala due to a diminishing Gulf of Tehuantepec gap wind event. S of 07N, gentle to moderate southerly winds and moderate seas prevail, except slight seas nearshore Colombia and eastern Panama. For the forecast, building high pressure N of the Caribbean and lower pressures near the monsoon trough will support pulsing fresh to strong easterly trade winds and moderate seas across the Gulf of Papagayo through Wed morning, then moderate to fresh through Fri, then fresh to strong again Fri night into next weekend. Rough seas in the far offshore waters of Guatemala will subside tonight. Moderate to fresh northerly winds will pulse in the Gulf of Panama this week. Gentle to moderate winds and slight to moderate seas will prevail elsewhere. ...REMAINDER OF THE AREA... A 1026 mb high center is analyzed just N of the area near 32N132W. Its associated ridge extends to near the Revillagigedo Islands. The pressure gradient between the high and relatively lower pressures near the ITCZ/Monsoon Trough is bringing moderate to fresh trade winds from 08N to 24N and W of 120W. Rough seas prevail over these waters per recent altimeter data, in mixed long period swell along with shorter period wind generated seas. Moderate southerly winds and moderate seas are occurring S of the monsoon trough and ITCZ. Mainly gentle to moderate winds and moderate seas prevail across the remainder of the open waters, except locally rough seas near 30N140W. For the forecast, high pressure will continue over the northern waters through the middle of the week leading to continuing fresh to strong easterly winds and rough seas over much of the tradewind belt west of 120W. Over the eastern part of the area, fresh to strong easterly winds and rough seas associated with the diminishing gale-force gap wind event in the Gulf of Tehuantepec will spread westward to near 106W from 08N to 12N through tonight. Seas to rough near 30N140W in W-NW swell will persist through much of tonight. Meanwhile, a tight pressure gradient will develop offshore southern California leading to fresh to strong winds and rough seas in the N-central waters early Wed. Marine conditions should improve overall during the upcoming weekend as the pressure gradient slackens.