000 AXPZ20 KNHC 180335 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Dec 18 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 09N84W to 09N94W. The ITCZ continues from 09N94W to 07N130W to beyond 08N140W. Scattered moderate convection is noted from 07N to 13N between 97W to 112W and from 06N to 13N between 113W to 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A surface trough crosses the northern Gulf of California and northern Baja California, then continues across the northern forecast waters to 28N115W to 25N130W. Latest observations indicate seas between 8 to 10 ft behind the trough. A ridge dominates the remainder of the offshore forecast waters on Baja California producing mainly a gentle NW to N flow. Gentle to moderate northerly winds are noted per scatterometer data inside the Gulf of California, south of 27N to 20N. Winds have diminished below 20 kt in the Gulf of Tehuantepec while mainly fresh NE winds are noted in the Gulf of Papagayo based on recent satellite derived wind data. Light to gentle winds are elsewhere over the open waters off Mexico. Seas are in the 6-8 ft range N of 20N and W of 110W and 4-7 ft elsewhere over the open waters off Mexico. Seas of 2-4 ft are in the Gulf of California. For the forecast, NW swell will continue to dominate the offshore forecast waters of Baja California with seas of up to 8 ft. This swell event will gradually decay during the upcoming weekend. Fresh to strong winds will develop in the north and central parts of the Gulf of California tonight through Sat. A new gap wind event is expected in the Tehuantepec region beginning on Sun night, with gale conditions possible on Tue. Seas are forecast to build to 10-12 ft with the strongest winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh to strong NE winds prevail across the Papagayo region. Light to gentle winds are noted elsewhere north of the monsoon trough. Gentle to moderate S to SW winds prevail south of the monsoon trough. Seas of 3 to 5 ft in mixed swell dominate the offshore waters. For the forecast, NE to E winds will pulse to fresh to strong in the Papagayo region through the next several days, particularly during the overnight and early morning hours. Gentle to moderate winds will prevail elsewhere. No significant swell events are forecast through early next week. REMAINDER OF THE AREA... A ridge dominates the waters north of the ITCZ. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is supporting fresh to locally strong trade winds north of the ITCZ to near 21N and west of 120W. Gentle to moderate winds prevail elsewhere. NW to N swell is dominating the waters west of 110W, producing seas of 8-11 ft. Seas of 5-7 ft are noted elsewhere. The aforementioned dissipating cold front has ushered in a set of reinforcing NW swell with seas up to 12 ft near 30N130W. For the forecast, an area of fresh to locally strong trade winds will persist across the west-central waters on Sat. The large NW to N swell will gradually decay through the weekend. The next cold front is forecast to move southeast of 30N140W early Sun with fresh to locally strong winds on either side of the front. The front will slowly progress east-southeast through early next week. The front will bring another NW swell event, building seas to 8-12 ft. $$ Torres