000 AXPZ20 KNHC 052134 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A low pressure has developed over the SW Gulf of Mexico. The low pressure will move rapidly northeastward dragging a reinforcing front across the Gulf of Mexico. 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 of 35-40 kt Mon 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 08N77W to 1010 mb low pressure near 09N94W to 07N105W to 1012 low pressure near 10N123W to 08N130W. The ITCZ continues from 08N130W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 08N to 13N between 120W and 124W, from 06N to 09N between 124W and 133W, and from 15N to 18N between 107W and 115W. Scattered moderate convection is seen from 08N to 11N between 90W and 93W. 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 8-9 ft. Seas over this area will continue to subside, falling below 8 ft late on Sunday. Another set of NW swell will enter the waters off Baja California on Mon. 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: Moderate to fresh NE to E winds are expected in the Papagayo region through Mon. Then, fresh to strong winds are expected Mon night through Thu night as high pressure builds over the western Caribbean. Near gale-force winds could be possible 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 next 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 1028 mb is centered near 32N128W. 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. 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. Large, long period, NW swell continues to propagate across most of the waters N of the equator and W of 110W. Several altimeter passes indicate seas in the 8-11 ft range in this area. Seas associated with this swell event will continue to slowly subside tonight and Sun. Another large NW swell event is currently reaching the NW corner of the forecast area. 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