534 AXPZ20 KNHC 041518 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Dec 4 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure building behind a cold front moving across the Gulf of Mexico and the eastern north Pacific monsoon trough is generating gale force winds in the Gulf of Tehuantepec. Gale force winds are expected through tonight. Winds will then diminish below gale force, with a stronger pulse of gale force winds expected Sun night through Tue night. Seas are forecast to build to 15-17 ft with this stronger pulse of gap winds by Tue. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.html for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 06N97W to 11N115W to 08N128W. The ITCZ continues from 08N128W to beyond 09N140W. Scattered moderate convection is noted from 05N to 08N E of 80W, including the Gulf of Panama, from 06N to 08N between 94W and 99W, from 07N to 11N between 107W and 111W, from 10N to 11N between 112W and 118W, and from 12N to 15N between 117W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more on the Gulf of Tehuantepec gale force gap wind event. Elsewhere, fresh to strong winds prevail over the Gulf of California, with seas in the 5-7 ft range. Strong gusty NE winds are funneling through the passes of the Baja California peninsula. NW swell has propagated into the waters off Baja California Norte, with seas in the 8-11 ft range. The swell event will continue to propagate southward, with 8 ft seas reaching the Revillagigedo Islands by late today. Seas over this area will subside through the weekend, falling below 8 ft on Sunday. Another set of NW swell will enter the waters off Baja California early next week. Seas will peak near 15 ft off Baja California Norte Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to locally strong NE to E winds are expected in the Gulf of Papagayo over the next couple of days, particularly during the overnight and early morning hours. Elsewhwere, light to gentle winds are expected north of the monsoon trough, with gentle to moderate S to SW winds south of the monsoon trough, through the upcoming weekend. Swell from the gale force gap wind event in the Gulf of Tehuantepec will impact the waters off Guatemala and El Salvador today, with seas building to 6 ft. Seas will build to 8-9 ft over these waters early next week as larger swell is generated from the stronger pulse of gale force gap winds over the Gulf of Tehuantepec. Seas in the 4-5 ft range will prevail elsewhere. REMAINDER OF THE AREA... High pressure of 1027 mb is centered near 39N128W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ, and within the monsoon trough, is supporting moderate to fresh trade winds roughly from 10N to 20N west of 120W. Seas are 8 to 11 ft in NW swell across this area. A ridge will persist across the northern forecast waters over the next several days, keeping a large area of fresh trade winds. Large, long period, NW swell continues to propagate across most of the waters N of the equator and W of 120W, with seas peaking near 12 ft. Seas associated with this swell will slowly subside through the weekend. Another large NW swell event will reach the NW corner of the forecast area by Sat. This swell will bring seas greater than 12 ft, and peaking near 17-18 ft, over much of the waters north of 20N on Tue. $$ GR