000 AXPZ20 KNHC 042115 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A ridge across the western Gulf of Mexico and the eastern slopes of the Sierra Madre Mountains in Mexico supports minimal gale-force winds across the Tehuantepec area. Gale force winds are expected tonight into the early morning hours on Sat. Winds will then diminish below gale force. A second and stronger gap wind event is expected in the Tehuantepec region Sun night through Wed night as another cold front develops near the Mexican coast late Sat. Seas are forecast to build to 14-15 ft with the latter event. 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 07N140W. Scattered moderate isolated strong convection is noted from 07N to 09N between 92W and 95W, and from 09N to 12N between 112W and 116W. Scattered moderate convection is seen near 14N119W and near 09N124W. 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, the most recent scatterometer pass shows fresh to strong NW-N winds over the Gulf of California N of 25N. Seas are in the in the 5-7 ft range. These winds and seas will diminish by tonight. Strong gusty NE winds will continue to funnel through the passes of the Baja California peninsula through this evening as strong high pressure remains over the Great Basin region of United States. NW swell has propagated into the offshore waters off Baja California with sea heights of 8-11 ft. This swell event will continue to propagate southward, with 8 ft seas reaching the Revillagigedo Islands this evening. Seas over this area will subside through the weekend, falling below 8 ft late on Sunday. Another set of NW swell will enter the waters off Baja California early next week. Seas will peak near 14 or 15 ft off Baja California Norte by Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Mainly fresh NE to E winds are expected in the Gulf of Papagayo at night through Mon night. Then, winds are forecast to increase to a fresh to strong breeze beginning on Tue, with near gale conditions possible by Wed as high pressure builds over the western Caribbean. 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 combined with SW swell will impact the waters off Guatemala and El Salvador through Sat night, with seas of 6-8 ft. Seas will build to 8-9 ft over these waters early next week as larger swell is generated from another gap wind event 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 36N127W. 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 16-17 ft, over much of the waters north of 20N on Tue. $$ GR