000 AXPZ20 KNHC 051558 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Dec 5 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: A ridge across the eastern slopes of the Sierra Madre Mountains will support fresh to strong northerly winds, with frequent gusts to gale force over the Gulf of Tehuantepec this morning. Winds will further diminish this afternoon, and then remain below gale force through much of the weekend. A cold front will enter the Gulf of Mexico tonight, and shift across the Gulf of Mexico through early next week. High pressure will build in the wake of the front, and support another round of gale force gap winds in the Gulf of Tehuantepec late Sun night through Wed night. This will be a stronger gap wind event with winds in excess of 40 kt late Mon into early Tue. Seas will build to 14-16 ft during this period of strongest winds. 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 08N77W to 1010 mb low pressure near 09N93W to 07N105W to 1010 low pressure near 10N118W to 08N130W. The ITCZ continues from 08N130W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 08N to 14N between 118W and 126W, from 06N to 09N between 126W and 134W, and from 15N to 18N between 109W and 113W. 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, moderate to locally fresh NW-N winds prevail over the Gulf of California, with seas in the in the 2-4 ft range. NW swell continues across the offshore waters off Baja California with sea heights of 8-10 ft. 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 to 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. Then, fresh to strong winds are expected in the Papagayo region Mon night through Wed night 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 upcoming gale force gap wind event in the Gulf of Tehuantepec will build seas to 8-9 ft over the waters off Guatemala and El Salvador early next week. Seas in the 4-5 ft range will prevail elsewhere. REMAINDER OF THE AREA... High pressure of 1026 mb is centered near 32N127W. 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 10 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. Seas associated with this swell have started to subside and will continue to 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, over much of the waters north of 20N on Tue. Seas will peak near 15-17 ft Tue before starting to subside. Seas greater than 8 ft with this swell will propagate SE across the area, covering much of the waters west of 105W by Wed night. $$ GR