122 AXPZ20 KNHC 121539 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1440 UTC. ...SPECIAL FEATURES... NW waters Gale Warning: A cold front extends across the NW waters from 30N134W to 24N140W. Scattered moderate convection is noted north of 27N within 150 nm east of the front. Gale force SW winds are occurring north of 26N within 120 nm or so east of the front, with fresh to strong S-SW winds around 300 nm elsewhere north of 22N and east of the front. Gale force winds which were also captured by overnight ASCAT scatterometer data west of the front are now 20-30 kt between the front and 140W. Very large NW swell accompanies the front, with seas of up to 27-29 ft near 30N140W, with a recent altimeter pass showing around 32 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 this evening, and then to 20 kt or less late tonight into early Fri as the front weakens. Gulf of Tehuantepec Gale Warning: Moderate NW-N winds across the Gulf of Tehuantepec will diminish by this afternoon. 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. This is expected to be a significant gale event, with a large area of offshore winds expected to reach to 40-45 kt Fri evening through Sat morning. Model guidance is indicating an increasing chance of minimal storm force winds Fri evening and night, and this will be monitored further this afternoon in case an upgrade to Storm Warning during these hours is required. 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. Please read the latest NHC High Seas Forecast at website www.hurricanes.gov/marine for more details on both Gale Warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from Colombia near 06.5N77.5W to 1010 mb low pressure near 06N79.5W to 10N85W to 06N96W. The ITCZ extends from 06N96W to 06N120W to beyond 07N140W. Scattered moderate convection is noted from 03N to 08N between 78W and 85W, from 04N to 09N between 116W and 127W, and from 06N to 08N between 137W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for details on a developing Gulf of Tehuantepec strong Gale Warning, possibly reaching minimal Storm Force Fri evening and night. Elsewhere, troughing extends along the Sierra Madre Occidentales of Mexico. High pressure of 1022 mb located near the Channel Islands of California reaching southeast to the Revillagigedo Islands dominates the waters. The pressure gradient between the high and troughing is producing fresh to strong NW-N winds in the central and southern Gulf of California, with moderate to fresh N winds filtering through Baja California passages into the waters west of the peninsula. 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, highest beyond 60 nm between Cabo San Lazaro and Punta Eugenia. Elsewhere seas are 3-5 ft offshore Chiapas and Oaxaca, and 4-7 ft in NW swell elsewhere, except 2-5 ft in the Gulf of California, highest near the fresh to strong winds. 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 night ahead of a decaying cold front, then may return Mon night ahead of 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. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong NE winds and 5-7 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 and Panama near a weak 1010 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 early Mon, fresh to strong south-southeast of the Azuero Peninsula Fri evening through early Sat, then again Sat evening into early Sun. A 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 and Sat night. 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 1022 mb located near the Channel Islands of California with a ridge extending southwest-west through 22N130W to 19N140W. Gentle to moderate anticyclonic winds are north of 15N and elsewhere southeast of the above mentioned cold front under the ridging. Moderate to fresh trades are north of the ITCZ to 15N 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 06N and west of 110W. Seas are 6-7 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 into Sat west of 125W as the gradient tightens. Another pair of cold fronts with 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