000 AXPZ20 KNHC 150900 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Dec 15 2021 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 0740 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W to 09.5N84W to 06.5N93W to 06.5N106W. The ITCZ extends from 06.5N106W to 08N118W to beyond 07N140W. Widely scattered moderate convection is noted from 05.5N to 09N between 80W and 109W, from 07N to 09N between 117W and 123W, and from 13.5N to 18N between 129W and 139W. Scattered moderate isolated strong convection noted from 12N to 15N between 110W and 117W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A ridge across the eastern slopes of the Sierra Madre Mountains in Mexico continues to support a strong gap wind event across the Tehuantepec region. 0300 to 0400 UTC ASCAT data showed strong northerly winds to 30 kt across the Gulf of Tehuantepec, with fresh to strong winds of 20-25 kt extending downwind to near 13.5N95.5W. Seas across this area are 8 to 10 ft. This strong gap wind event is expected to prevail through Wed night before diminishing significantly in strength and areal coverage. Winds are expected to diminish to fresh to strong and remain confined to the Gulf of Tehuantepec Thu through Friday morning before shutting down. Light to gentle winds prevail elsewhere across the Mexican offshore waters from the Tehuantepec region to Las Tres Marias. Seas across this area are 4-6 ft in mixed NW and SW swell. A cold front has entered the far NW offshore waters of Baja Norte tonight and extends from the far N Gulf of California to 30N115W to beyond 26.5N120W. Fresh W to NW winds prevail between the front and Punta Eugenia waters, while moderate to fresh northerly winds spread farther southward to Baja Sur. Seas continue to build in NW swell and are 8-15 ft north of Punta Eugenia and 7 to 10 ft from Punta Eugenia south to 18N. Strong SW to W winds to 30 kt are across the northern Gulf of California between the front, along 31.5N, and 29.5N. Seas there have built quickly to 9 ft in recent hours. Gentle to moderate northerly winds prevail elsewhere across the the Gulf to the south, with seas of 2 to 4 ft. The cold front will move continue to move SE across the waters W of Baja California Norte tonight and reach near Punta Eugenia by sunrise. Moderate to fresh W to NW winds are expected ahead of the front N of Punta Eugenia while fresh to strong SW winds in the northern Gulf of California will prevail tonight. A brief period of fresh to locally strong NW winds will follow the front late tonight and early Wed across both the offshore waters and inside the Gulf of California. Large NW swell will continue to propagate across the offshore waters of Baja California and peak at 10-15 ft N of Punta Eugenia prior to sunrise. Seas of 8-9 ft, will reach the Revillagigedo Islands by Wed night into Thu morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh to strong NE to E prevail across the Papagayo region tonight and extend to 90W, and are expected to pule to strong at night through Thu night. Seas will generally persist at 6-7 ft. Gentle to moderate northerly winds and seas 3 to 4 ft in the Gulf of Panama are forecast to pulse nightly through Wed night. Moderate S to SW winds are south of the monsoon trough with seas to 6 ft in SW swell. Light to gentle variable winds are elsewhere. These conditions are forecast to remain for much of the week. REMAINDER OF THE AREA... The cold front extends from 30N115W to 26.5N120W, where it transitions to a shearline on to 19N140W. High pressure SE of the front earlier tonight has collapsed. This front is forecast to continue moving SE over the northern forecast waters through Wed before dissipating. The largest NW swell of the season thus far will follow the front into the regional waters tonight, and is currently peaking near 18 ft along 30N. Moderate N to NE winds are found north of the front becoming fresh NE winds W of 130W. The pressure gradient between building high pressure and the ITCZ will maintain a zone of fresh to locally strong trade winds from 08-23N between 118W and 140W through Wed through Fri. The large NW swell will spread into the deep tropics by early Thu, with seas to 12 ft expected to reach as far S as 13N by early Thu and gradually subside across the regional waters through Fri. $$ Stripling