000 AXPZ20 KNHC 061537 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Dec 6 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: Low pressure over the SW Gulf of Mexico will move rapidly northeastward dragging a cold front across the Gulf of Mexico. The pressure gradient between high pressure building in the wake of the front and the eastern north Pacific monsoon trough will support another round of gale force gap winds in the Gulf of Tehuantepec late tonight through Wed night. This will be a stronger gap wind event than the one which just ended, with winds in excess of 40 kt Mon night through Wed and building seas 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 a 1011 mb low pressure over northern Colombia near 08N75W to 09N90W to 1009 mb low pressure near 08N97W to 07N104W to 1009 mb low pressure near 13N113W to 08N134W. The ITCZ continues from 08N134W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 08N to 10N between 92W and 97W, from 07N to 11N between 105W and 112W, from 10N to 13N between 120W and 123W, and from 06N to 09N between 128W and 138W. Similar convection is observed from 12N to 17N between 104W and 115W. 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 fresh NW-N winds will prevail over the Gulf of California today, with mainly gentle to moderate winds the remainder of the forecast period. Seas will build to 5 or 6 ft today. Seas continue to subside across the offshore waters of Baja California, falling below 8 ft late today. Another set of NW swell will enter the waters off Baja California on Mon. 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: Moderate to fresh NE to E winds are expected in the Papagayo region through Mon. Winds will increase to fresh to strong Mon night through Thu night as high pressure builds over the western Caribbean. Winds may reach near gale-force Wed night and Thu. 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 next several days. Swell from the upcoming gale force gap wind event in the Gulf of Tehuantepec will propagate over the waters off Guatemala and El Salvador early this week, building seas of up to 9 or 10 ft mainly Mon night through Tue night. Seas in the 4-5 ft range will prevail elsewhere. REMAINDER OF THE AREA... High pressure of 1030 mb is centered near 36N130W. 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 9 ft in subsiding NW swell and NE wind waves 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. A weak low pressure from southern California will reach the waters N of Punta Eugenia on Tue. The pressure gradient between the low and high pressure to the west will briefly bring fresh to strong northerly winds over the waters N of 25N between 122W and 130W on Tue. Subsiding NW swell prevails across most of the waters N of the equator and W of 110W, with seas of 7-9 ft. Seas associated with this swell will continue to slowly subside. Another large NW swell over the NW corner of the forecast area will spread SE across the forecast waters. 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 event will cover much of the waters west of 105W by Wed night. $$ GR