000 AXPZ20 KNHC 122113 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jan 12 2023 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 2030 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: Fresh to strong winds will return late this evening, quickly increasing to gale force after midnight tonight, and continuing through Sat night, as high pressure surges across eastern Mexico behind a cold front moving through the Gulf of Mexico. There has been an increasing chance for minimal storm force winds from Fri evening into the overnight hours, and the warning has been upgraded to a Storm Warning. A large surrounding area of gale force winds is expected. Large seas will build with these winds, peaking at 18-20 ft Fri night into early Sat. Fresh to strong winds will then be present Sun morning, quickly dimishing to 20 kt or less Sun afternoon. Rather tranquil conditions are forecast for early next week with gentle to moderate onshore flow and 2-4 ft seas in the immediate Gulf. NW waters Gale Warning: A cold front extends across the NW waters from 30N130.5W to 22N140W. Scattered showers are possible north of 26N within 120 nm east of the front. Gale force SW winds are occurring north of 27N within 120 nm or so east of the front per recent ASCAT scatterometer data, with fresh to strong S-SW winds around 300 nm elsewhere north of 23N and east of the front, with W-NW fresh to strong winds north of 24N and west of the front. Very large NW swell accompanies the front, with seas of up to around 27 ft near 30N140W, with a recent altimeter pass showing around 30 ft west of 140W. Seas of 12 ft or greater extend to the southeast edge of the S-SW fresh to strong winds. Winds are forecast to diminish below gale force later this evening, and then to 20 kt or less late tonight into early Fri as the front weakens. Please read the latest NHC High Seas Forecast at website www.hurricanes.gov/marine for more details on both Warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Colombia near 07N77W to 1011 mb low pressure near 06N79.5W to 09N85W to 06N94W. The ITCZ extends from 06N94W to 05N100W to 06N120W to beyond 07N140W. Scattered moderate convection is noted from 03N to 09N between 77W and 87W, from 04N to 10N between 116W and 125W, and from 05N to 09N between 138W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for details on a developing Gulf of Tehuantepec Storm Warning. Elsewhere, troughing extends along the Sierra Madre Occidentales of Mexico. High pressure of 1023 mb centered southwest of the California/Mexico border extends a ridge southeast through the Revillagigedo Islands. The pressure gradient between the high and troughing is producing fresh to strong NW-N winds in the central and southern Gulf of California per recent ASCAT scatterometer data, with moderate to fresh N winds filtering through Baja California Sur passages downwind across the waters west of the peninsula, as well as in the northern Gulf of California. Winds are moderate or weaker across the remainder of the waters. The latest pulse of NW swell across the Baja waters is producing seas of 7-11 ft per earlier altimeter data, higher just beyond 250 nm. Elsewhere, seas are 4-7 ft east of 109W, except 3-6 ft in the Gulf of California. For the forecast, outside of the Gulf of Tehuantepec, fresh to strong winds in the central and southern Gulf of California will diminish Fri. Fresh to near gale force SW-W winds will develop in the northern Gulf of California Sat night through Sun evening ahead of a decaying cold front, then may return Mon through Tue both of ahead of and behind another front. Seas will build to 4-7 ft in the Gulf with the fresh to strong wind areas. NW swell of 8 ft or greater offshore Baja California will shift slightly southeast tonight while decaying, with a larger set arriving offshore Baja California Norte by early Fri, peaking to 16 ft NW of Punta Eugenia Fri evening. Seas of 8 ft or greater will cover the entire offshore waters this weekend. Another set of large NW swell is expected offshore Baja California Mon night through at least Tue night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh NE winds and 4-6 ft seas are across the Papagayo region. Moderate N-NE winds prevail across the Gulf of Panama to the Azuero Peninsula. Winds are moderate or weaker elsewhere. Seas are 3-5 ft offshore Colombia, 5-7 ft offshore Ecuador and SW of the Galapagos Islands, and 4-6 ft elsewhere. Scattered showers and isolated thunderstorms are offshore Colombia, Panama, and Costa Rica near a weak 1011 mb low pressure at 06N79.5W. For the forecast, fresh to strong offshore winds will pulse across the Gulf of Papagayo region through the next several days, increasing to near gale force early Sat through early Mon, as a Caribbean cold front moves into Central America. Minimal gale force winds are possible early Sun. Seas will build to 7-10 ft during the strongest winds. Moderate to fresh N-NE winds will develop in the Gulf of Panama and near the Azuero Peninsula Fri through Mon, fresh to strong south-southeast of the Azuero Peninsula Fri evening through Sun night. A storm force gap wind event in the Gulf of Tehuantepec will extend fresh to strong winds in the other offshore waters of Guatemala Fri evening through Sat morning, with associated seas building to 8-14 ft there. Winds will be moderate or weaker elsewhere through at least the next several days, except moderate to fresh offshore Gulf of Fonseca Sat through early Sun. REMAINDER OF THE AREA... Please refer to the Special Features section for details on a Gale Warning associated with a cold front over the NW waters. Elsewhere, high pressure of 1023 mb centered southwest of the California/Mexico border extends a ridge southwest through 20N130W to 18N140W. Gentle to moderate anticyclonic winds are north of 16N and elsewhere southeast of the above mentioned cold front under the ridging. Moderate to fresh trades are north of the ITCZ to 16N and west of 110W. Winds are moderate or weaker elsewhere. Seas of 8 ft or greater in NW swell covers the waters north of about 05N and west of 110W. Seas are 5-7 ft elsewhere. For the forecast, outside of the NW waters Gale Warning discussed in the Special Features section, pulses of NW swell will propagate through the discussion waters through the remainder of the week and into the weekend, with seas of 8 ft or greater covering the majority of the open waters by the end of the weekend. High pressure and moderate to fresh winds will dominate the trade wind belt, increasing to fresh to strong Fri night through Sun west of 125W as the gradient tightens. Another pair of cold fronts with large, reinforcing swell may push just south of 30N this weekend into early next week. Fresh to strong winds north of 28N may accompany both fronts. $$ Lewitsky