000 AXPZ20 KNHC 010316 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Jan 1 2024 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 0300 UTC. ...SPECIAL FEATURES... Large Swell Event Across Eastern Pacific: Large NW swell of 12 to 14 ft is occurring from 04N to 20N west of 110W, and with a new swell group impacting waters north of 28N and west of 115W. Seas elsewhere west of 90W are 8 to 12 ft in a mix of swell, to include shorter period swell emerging from persistent gap winds across the Gulf of Tehuantepec and Gulf of Papagayo. Please refer to the High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for details on both special features. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 09N84W to 05N95W. The ITCZ extends from 05N95W to 08N125W to beyond 03N140W. Scattered moderate convection is noted from 09N to 10N between 115W and 118W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong N winds are pulsing in the Gulf of Tehuantepec. Gentle winds are observed elsewhere. Recent altimeter satellite data showed combined seas of 10 to 12 ft west of 110W, including the waters offshore of Baja California south of Punta Eugenia, due to long- period NW swell mentioned in the Special Features section. Seas across the waters to the east of 110W are 7 to 10 ft in NW swell. In the Gulf of California, seas are 2 to 3 ft. For the forecast, winds will briefly pulse to minimal gale force across the Gulf of Tehuantepec Mon night, related to a cold from moving through the Gulf of Mexico. Farther north, large NW swell off Baja California Sur will subside below 12 ft overnight. New NW swell will accompany and cold front moving into Baja California Norte Mon. Combined seas off Baja California will subside below 8 ft into mid week. Looking ahead, the next cold front will reach the waters west of Baja California late Wed. Another round of large NW swell will follow in behind this front, affecting the waters west of Baja California Wed night through the end of the week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE gap winds persist across the Gulf of Papagayo, down a little bit from the near-gale force wind indicated in a scatterometer satellite pass from several hours ago. Seas are estimated near 8 ft. Farther north, seas of 7 to 9 ft in NW to N swell is noted offshore Guatemala and El Salvador due to a Gulf of Tehuantepec gap wind event. Moderate to fresh N winds continue in the Gulf of Panama. Elsewhere, quiescent marine conditions dominate the waters with gentle to moderate winds and seas of 4 to 6 ft in mixed swell. For the forecast, a building ridge north of the area will support fresh to strong NE gap winds over the Gulf of Papagayo through Wed, with 8 to 9 ft combined seas. Meanwhile, seas of 7 to 8 ft will continue offshore Guatemala and El Salvador through mid- week due to continued NW swell over the area. Fresh N winds will pulse at night in the Gulf of Panama through Tue night. Otherwise, a weak pressure gradient will result in moderate or lighter winds across the rest of the area through early next week. ...REMAINDER OF THE AREA... See the Special Features Section above for details on the large NW swell across most of the forecast waters. The pressure gradient between high pressure ridging along 25N and lower pressure associated with the ITCZ is yielding fresh to strong NE trades from 05N to 20N and west of 125W. Moderate to locally fresh trades are noted elsewhere from the ITCZ to 22N, and west of 110W. South of the ITCZ and monsoon trough, winds are moderate or less. A cold front extends from 30N121W to 25N135W with fresh strong winds on both sides of the front, north of 28N between 120W and 125W, north of 25N. The sea conditions are described in the special features section above. For the forecast, see the Special Features section above for details on the large swell over much of our forecast waters. The current NW swell will subside to the 8 to 12 ft range across most of the area overnight. Elsewhere, the cold front will weaken by Mon evening as it approaches Baja California. Fresh to strong winds are expected north of 27N with this front through this evening. High pressure building across the northwest waters will enhance NE trades between the ITCZ and 20N, and to the west of 125W through most of the week, bringing strong winds and 9 to 13 ft seas to the area. The next cold front will enter the northwest waters Mon night, extend from near 30N129W to 26N140W Tue evening, and from near 30N118W to 25N130W by midday Wed. Large NW swell coming in behind this front will build seas to 12 to 15 ft across the waters north of 25N Tue night through Thu. $$ Christensen