000 AXPZ20 KNHC 012151 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Dec 1 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: A ridge across the eastern slopes of the Sierra Madre mountains in Mexico and the western Gulf of Mexico currently supports a gale-force gap wind event across the Tehuantepec region. A recent ASCAT pass confirmed the presence of these wind speeds. Seas are forecast to build to 12-13 ft by tonight. The gale force winds will persist trough early Fri morning. Then, strong to just below gale force winds are expected on Fri, extending downwind to about 12N, before winds increase again to gale force Fri night through Sun night as the high pressure strengthens again across the western Gulf of Mexico. Winds could increase to 40 kt by Sat night with seas to around 13 ft. Winds are then expected to gradually diminish Mon and Mon night. Please see the latest High Seas Forecast at http://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Pacific Gale Warning: A strong cold front is now reaching the far NW corner of the forecast region. A pre-frontal trough extends 30N133W to 24N140W. Fresh to strong southerly winds are noted ahead of the trough, mainly N of 28N and E of the trough to about 129W based on recent scatterometer data. Strong to minimal gale-force winds and large seas will follow the front forecast to reach from 30N131W to 27N140W this evening, and from 30N127W to 26N140W by early Fri morning. Seas will build to 15-16 ft behind the front in mixed NE wind waves and strong NW swell. Gale conditions are expected to end by late tonight as the front moves slowly southward and the pressure gradient relaxes. Please see the latest High Seas Forecast at http://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N77W to 07N100W to 1010 mb low pressure located near 12N116W to 09N120W. The ITCZ continues from 09N120W to 09N130W to 10N140W. Scattered moderate isolated strong convection is from 13N to 16N between 114W and 117W, and from 08N to 12N W of 124W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Light to gentle winds dominate the offshore forecast waters of Baja California as a 1019 mb high pressure remains located near 28N119W. Seas are 3-5 ft. Light winds and seas 3 ft or less prevail inside the Gulf of California. Elsewhere across the remaining Mexican offshore waters, outside of the Tehuantepec region, mainly light to gentle winds and seas of 3 to 5 ft are noted. Minimal gale-force winds are seen based on scatterometer data across the Gulf of Tehuantepec where seas are 8-11 ft. For the forecast, gale-force winds will persist in the Tehuantepec area through early Fri morning. Please, see the Special Features section for more details. A cold front is expected to approach the Baja California Norte waters on Sat, and will dissipate on Sun before reaching the area. Accompanying large NW swell will reach the Baja Norte waters Fri evening, with seas building to 7-9 ft N of Punta Eugenia Fri night, before beginning to slowly fade by late Sat. High pressure will build across the Baja region Sun night through Mon and freshen the winds across the Baja California waters. Gentle to moderate winds and slight seas are forecast in the Gulf of California through the upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE-E winds are blowing across the Papagayo region and downwind to near 92W. Peak seas are estimated at 8 ft. Light to gentle variable winds prevail elsewhere N of the monsoon trough along 07N, with seas of 4 to 5 ft while moderate S to SW winds and 5 to 6 ft seas are seen to the S of the trough. Gentle to moderate S to SW winds prevail off the Ecuador offshore waters to the Galapagos Islands with seas 4 to 5 ft. For the forecast, fresh to strong gap winds over the Papagayo region will persist trough Sat, then mainly moderate to fresh winds are expected the remainder of the forecast period. Elsewhere, little change in the marine conditions is forecast. Mainly gentle to moderate winds will prevail across the offshore waters of Central America, Colombia, and Ecuador. Seas will subside modestly during the upcoming weekend, except in the Papagayo region. NW swell generated from a significant Tehuantepec gap wind event will move across the offshore waters of Guatemala and El Salvador early Fri through Sun night. REMAINDER OF THE AREA... A 1019 mb high pressure is centered across the NE forecast waters near 28N119W, and extends a ridge south and southeastward that covers roughly the waters N of 18N between 110W and 130W. This system is producing a light to gentle anticyclonic flow across the area. A 1010 mb low pressure remains embedded in the monsoon trough near 12N116W. Some shower activity is noted N of the center. The pressure gradient between this low and high pressure to the N supports an area of fresh NE winds from 13N-20N between 115W-120W based on satellite derived wind data. Seas are 5-6 ft within these winds. Elsewhere N of the monsoon trough gentle to moderate winds and seas of 4-6 ft are noted. Moderate to locally fresh SE to S winds winds and seas of 6 to 7 ft are seen S of the monsoon to the equator and W of 120W. A cold front has reached the far NW corner of the forecast region. A recent ASCAT pass nicely shows the front position with strong to minimal gale force northerly winds behind the front and just N of 30N. A pre-frontal trough extends 30N133W to 24N140W. See the Special Features section above for more details. For the forecast, the pre-frontal trough will move slowly SE across the NW waters into Fri, preceded by fresh to locally strong SW winds shifting ahead of it. A strong cold front will follow the trough. The front is forecast to dissipate on Sun over the northern forecast waters. At the same time, a reinforcing cold front will weaken along 30N Sun. High pressure behind that front will strengthen winds to fresh to locally strong across much of the area N of the ITCZ and W of 115W on Mon. A weak high pressure center will persist over the NE waters through Sun. The low pressure along the monsoon trough will open up into a trough by Sat and will continue to move westward on Sun. $$ GR