000 AXPZ20 KNHC 220210 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Dec 22 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 0000 UTC surface analysis and satellite imagery through 0100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: High pressure currently over eastern Mexico and the SW Gulf of Mexico behind a cold front is supporting strong to near gale force N-NE winds in the Tehuantepec region. Seas are 8-9 ft. The pressure gradient will weaken here through early Thu allowing for winds to diminish and residual fresh seas to subside Thu night. The next cold front, much stronger, is forecast to cross the Gulf of Mexico by the end of the week. Stronger high pressure will arrive behind the front resulting in fresh to strong winds returning in the Gulf of Tehuantepec by early Fri, rapidly increasing to gale force Fri afternoon, then to storm force Fri evening. Gales could then last through at least Mon night. Very large and dangerous seas will occur with this gap wind event, peaking to at least around 20 ft late Thu night into early Fri. 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 extends from western Colombia near 06N77W to 09N87W to 05N105W. The ITCZ extends from 05N105W to 1010 mb low pressure near 06N116W to 04N121W to 08N140W. Scattered moderate convection is noted from 07N to 09N between 111W and 115W, and within 90 nm N-NE of the ITCZ between 123W and 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about an upcoming storm force gap wind event in the Gulf of Tehuantepec. High pressure ridging combined with a trough along mainland NW Mexico is contributing toward moderate to fresh NW winds in the Gulf of California. Seas are 3-6 ft. NW winds offshore of Baja California are moderate to locally fresh with seas of 4-5 ft. Elsewhere winds are moderate or weaker with seas of 3-5 ft. For the forecast, aside from the Gulf of Tehuantepec storm force gap wind event, moderate to fresh NW winds in the Gulf of California will diminish by early Thu. 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 4-7 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 141W. 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 fresh to strong north of about 24N and west of 134W. Scattered showers with possible embedded thunderstorms are occurring north of 18N and west of 136W. Seas reach up to 16-17 ft mixed wind waves and NW swell within the area of fresh to strong winds. Elsewhere, ridging extends from high pressure centered north of area through 30N127W to 23N140W, and from 30N127W to 15N110W. Moderate or weaker winds are under the ridge along with seas of 4-6 ft north of 20N and east of 130W. The moderate pressure gradient between the ridge and lower pressure over the ITCZ is forcing moderate to fresh NE to E trades from 06N to 18N west of 115W. Seas are 6-9 ft. For the forecast, the fresh to strong 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, building to 12-14 ft in the far NW corner in reinforcing swell by the end of the weekend into early next week. $$ Lewitsky