000 AXPZ20 KNHC 121559 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Dec 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 1500 UTC. ...SPECIAL FEATURES... Tehuantepec Gale Warning: High pressure over the W Gulf of Mexico is forcing gale-force gap winds over the Gulf of Tehuantepec this morning. Ship C6DL4 reported 30 kt N winds at 1300 UTC in the Gulf of Tehuantepec just to the east of where the strongest winds are likely occurring. Highest seas are around 17 ft. 8 ft seas extend west-southwestward to 10N105W. These N to NE gap winds will only gradually diminish over the next couple of days with gale conditions ending Thu night. Please read the latest High Seas Forecast and the Offshore Waters Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and www.nhc.noaa.gov/marine/offshores.php for details on the special feature. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 09N85W to 06N94W. The ITCZ stretches from 06N95W to beyond 06N140W. Scattered moderate isolated strong convection is present from 04N-08N west of 127W. Scattered moderate convection is noted from 05N-10N between 105W-118W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the SPECIAL FEATURES section for details on a Gale Warning for the Tehuantepec region. Aside from the Tehuantepecer event, winds throughout the Mexican offshores are moderate or weaker this morning. Seas are 4-6 ft over the Pacific waters and 1-3 ft over the Gulf of California. For the forecast, building high pressure over the U.S. Great Basin should produce fresh to strong NW winds over the Gulf of California starting on Fri. Elsewhere, winds are moderate or weaker. Looking ahead, a new gale-force gap wind event over the Gulf of Tehuantepec may begin on Sat. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A strong north-south pressure gradient across the W Caribbean is forcing fresh to strong NE winds over the Gulf of Papagayo region today. Seas are 6-9 ft. Large 8-10 ft NW swell produced by the Gulf of Tehuantepec gap wind event is impacting the offshore waters of Guatemala and El Salvador. Elsewhere, winds are moderate or weaker with seas of 3-5 ft. For the forecast, the strong NE winds over the Gulf of Papagayo should continue through Thu night before diminishing. The large NW swell over the Guatemala and El Salvador waters will only gradually diminish through Fri. Elsewhere, winds are moderate or weaker for the next several days. ...REMAINDER OF THE AREA... A weak 1024 mb high centered at 31N137W along with low pressure associated with the ITCZ is forcing moderate to fresh NE trades between 08N-25N across the basin. Seas are 8-10 ft south of 20N west of 120W due to combined NE wind waves and SE swell. Large 8-10 ft NW to N swell being produced by the Gulf of Tehuantepec gap wind event extends equatorward to 05N and westward to 105W. A large extratropical low will approach the NW corner of our waters on Thu with strong to near-gale S to SW winds ahead of its associated cold front. After the front reaches the NW corner on Thu night, strong to near-gale W to NW winds should occur north of 23N west of 130W through Sat. It is possible that this system may reach gale conditions. Very large NW swell will be accompanying this system with seas up to 18 ft and 12 ft seas continuing through the weekend north of 20N west of 125W. The remainder of the waters will have winds moderate or weaker and seas 6-8 ft. $$ Landsea