Tropical Weather Discussion
Issued by NWS
Issued by NWS
666 AXPZ20 KNHC 110717 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Dec 11 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 0600 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08.5N78W to 06.5N90W to 10N109W to 09N110W. The ITCZ continues from 09N110W to 10.5N133W to beyond 09N140W. Scattered moderate and isolated strong convection is noted from 09N to 14N between 99W and 108.5W, and from 06.5N to 18.5N between 109W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong gap winds are over and downstream the Gulf of Tehuantepec per recent ASCAT scatterometer data, with seas of 5-7 ft. Elsewhere, a ridge extends from high pressure located N of the area to across the offshore forecast waters of Baja California. The pressure gradient between this ridge and a trough over western Mexico is supporting moderate to locally fresh winds in the central and southern Gulf of California, as well as near Cabo Corrientes. Light to gentle winds and moderate seas in long period mixed swells are noted across the remainder of the Mexican offshore waters, with slight to moderate seas in the Gulf of California and nearshore SW Mexico. For the forecast, fresh to strong northerly gap winds will prevail in the Gulf of Tehuantepec through Fri morning, then moderate to fresh through Sat morning. Winds over Tehuantepec will strengthen again on Sat afternoon and night, possibly reaching gale-force Sun night through at least Mon night. Mainly gentle to moderate winds and moderate seas will prevail elsewhere, locally fresh near Cabo Corrientes and in the Gulf of California through the end of the week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong winds are over and downstream the Gulf of Papagayo. Light to gentle winds are elsewhere N of 05N, except moderate in the Gulf of Panama per earlier ASCAT data. Gentle to locally moderate southerly winds prevail S of 05N, except locally fresh near the entrance to the Gulf of Guayaquil. Seas are mainly moderate in mixed SW and NW swell, with exception of slight seas nearshore from Colombia northward to Costa Rica, as well as near the Galapagos Islands. For the forecast, moderate N winds will pulse in the Gulf of Panama. Otherwise, mainly gentle winds will prevail N of the monsoon trough over the next several days, except pulsing to moderate to fresh in the Gulf of Papagayo, locally strong at times. Gentle to moderate winds will prevail S of monsoon trough. Moderate seas in mixed SW and NW swell are expected over the regional waters through the weekend and into early next week. Seas may build offshore Guatemala by early next week due to a possible Gulf of Tehuantepec gap wind event. ...REMAINDER OF THE AREA... High pressure dominates the waters N of the ITCZ and monsoon trough. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ and monsoon trough is supporting moderate to fresh winds N of the ITCZ to around 20N and west of 110W per recent ASCAT scatterometer passes. Seas are in the 5 to 7 ft range over these waters. Gentle to moderate winds, and seas of 4 to 7 ft, prevail elsewhere over the discussion waters, except near 30N140W where new NW swell is arriving and building seas to around 8-9 ft as confirmed by recent altimeter data. For the forecast, the new set of NW long period swell is forecast to spread SE of 30N140W today with seas to 8-9 ft over these waters before subsiding by the end of the week. The pressure gradient may tighten by the end of the weekend with trades just N of the monsoon trough and ITCZ freshening into early next week. $$ Lewitsky