000 AXPZ20 KNHC 212156 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Dec 21 2022 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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: High pressure over E Mexico/SW Gulf of Mexico behind a cold front over the SE Gulf of Mexico is causing a Gulf of Tehuantepec gap wind event this afternoon. Ship 3FWH8 reported NE 40 kt and 10 ft seas at 1800 UTC this afternoon offshore of the Gulf. These may be the peak winds occurring in the event currently. As the pressure diminishes over E Mexico/SW Gulf of Mexico, the gap wind event should drop below gale force later tonight. The Sentinel-3A altimeter satellite measured peak seas of 10-11 ft at 1630 UTC over the Gulf of Tehuantepec, close to the highest of what may be occurring. Seas should drop below 8 ft by late tonight. Looking ahead, a strong cold front crossing the Gulf of Mexico is expected to produce a more significant Tehuantepec gap wind event Fri through the weekend. Gales could last from Fri afternoon through at least Mon night, with storm force winds possible on Fri night. Peak seas are expected to be near 15 ft from Fri night through Sat night. Please read the latest High Seas Forecast issued by the the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis near the Panama-Colombia border at 07N78W to 06N100W. The ITCZ extends from 06N100W to at 1010 mb low at 06N114W, and then to beyond 08N140W. Scattered moderate convection is present from 05N-09N between 124W-134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about an ongoing gale event in the Gulf of Tehuantepec that is expected to diminish later tonight and then begin again Fri afternoon. High pressure ridging combined with a trough along mainland NW Mexico is contributing toward fresh to strong NW winds in the Gulf of California. Seas are 4-6 ft. NW winds offshore of Baja California are moderate to fresh with seas of 4-5 ft. Elsewhere winds are moderate or weaker with seas of 3-4 ft. For the forecast, aside from the on-going Gulf of Tehuantepec event, the fresh to strong NW winds in the Gulf of California will diminish tonight. Fresh NW winds should again develop Sat and Sat night in the Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E gap winds are occurring over the Gulf of Papagayo region with seas of 4-6 ft. Seas over the Guatemala offshores are 4-6 ft in mixed NW swell from the Gulf of Tehuantepec and E swell from the Gulf of Papagayo. Elsewhere winds are moderate or weaker with seas 3-5 ft. For the forecast, fresh to strong NE to E gap winds will continue to pulse in the Papagayo region through the rest of the forecast period. Gentle to occasionally moderate winds will continue elsewhere for the next several days. Seas to 8 ft offshore Guatemala due to NW swell from a Gulf of Tehuantepec gap wind event will diminish steadily on Thu. A larger NW swell is expected in the Guatemala offshore zone Fri night through at least Mon night due to a stronger Gulf of Tehuantepec gap wind event. REMAINDER OF THE AREA... A complex low pressure system northwest of the area has an associated cold front that is along 142W. The low and associated front will shift northeastward through Thu, remaining northwest of our forecast area. S winds to the east of the cold front are reaching strong to near gale north of 25N and west of 135W. Scattered moderate convection is occurring from 20N-30N west of 138W. Seas reach up to 18 ft mixed wind waves and W swell within the area of strong to near gale winds. Elsewhere, ridging extends from a 1028 mb high centered at 33N126W southeastward to 17N105W. The moderate pressure gradient between the ridge and low pressure over the ITCZ is forcing moderate to fresh NE to E trades between 07N-23N. Seas are 6-8 ft. For the forecast, the strong to near gale S winds in our NW corner waters will shift north of the discussion area by early on Thu. Seas in the area will subside to below 12 ft by Thu afternoon, while residual NW swell of 8-10 ft will continue for the next few days.the NE to E trades are expected to have little change for the next few days. Moderate NW swell will propagate across the western waters during the next few days, with 8-12 ft seas occurring north of 07N and west of 125W through the weekend. $$ Landsea