000 AXPZ20 KNHC 302148 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Dec 30 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 2130 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong high pressure centered over NE Mexico is forcing gale force winds across the Gulf of Tehuantepec, confirmed by a recent ASCAT satellite data pass. The gale force northerly gap winds are expected to persist through early Sun morning, diminishing late Sunday morning. Seas of 12 to 13 ft will persist through tonight. Seas will then subside by Sun night across the region. Large Swell Event Across Eastern Pacific: A cold front stretches from 30N118W to 27N120W, dissipating to 21N130W. Large WNW to NW swell, with seas of 12 to 17 ft, is occurring north of 05N and west of 112W. The 8 ft seas extend southward beyond the Equator, and as far east as 15N101W. The front will dissipate tonight over the Baja California offshore waters. However, the reinforcing swell will continue to spread south and east across the waters through early Mon. Seas will subside below 16 ft tonight and below 13 ft by Sun evening. 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 09N79W to 08N86W to 04N96W. The ITCZ continues from 04N96W to 07N112W to beyond 06N140W. Scattered moderate convection is noted from 03.5N to 09N between 102W and 117W, and from 05N to 08N between 132W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features Section above for details on a Gale Warning for the Gulf of Tehuantepec. A cold front extends from 30N118W to 27N120W, dissipating to 21N130W. Recent ASCAT satellite data shows moderate NNW winds to the west of Baja California. Seas west of Baja California Norte are 11 to 17 ft in large NW swell. Seas west of Baja California Sur are 9 to 15 ft in large NW swell. In the Gulf of California, gentle winds and 1-3 ft seas are present. Gentle to moderate winds are elsewhere offshore Mexico, except gale force in the Gulf of Tehuantepec. Seas west of Jalisco are 9 to 12 ft in NW swell. Seas off Guerrero are 6 to 10 ft in NW swell. For the forecast, the cold front extending from 30N118W to 27N120W will dissipate tonight as it moves eastward through the Baja California offshore waters. Very large NW swell impacting the Baja California offshore waters will bring seas of 12 to 16 ft tonight, then subside below 12 ft Sun afternoon. Seas of 8 to 11 ft are expanding across most of the southwest and southern Mexico offshore waters, and will persist through the weekend. A second cold front will move through the Baja California offshore waters late Sun night through Mon, keeping seas in the 8 to 10 ft range offshore early next week through Tue. In the Gulf of Tehuantepec, fresh to strong N winds are expected Sun afternoon through Sun night, briefly diminishing early Mon. Strong to near gale force N winds will then return Mon evening through early Tue before diminishing Tue afternoon. Looking ahead, the next gap wind event in the Gulf of Tehuantepec should begin Wed night or Thu, with strong to near-gale force N winds possible. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate NE to E winds are occurring in the Gulf of Papagayo region. Seas of 6 to 8 ft in N swell are occurring offshore Guatemala due to a Gulf of Tehuantepec gap wind event. Elsewhere, quiescent marine conditions dominate the waters with gentle to moderate winds and seas of 4-6 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 region tonight through early Wed. Seas will build to 8 ft by Sun. Meanwhile, gale-force gap winds in the Gulf of Tehuantepec will cause NW swell with seas 7 to 9 ft over the Guatemala and El Salvador offshore waters through Sun night. Fresh N winds will pulse at night in the Gulf of Panama from Sun night 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 a 1025 mb high at 28N134W and the ITCZ is yielding fresh to locally strong NE trades from 12N to 15N between 128W and 134W, with moderate to fresh trades elsewhere from the ITCZ to 22N, and west of 120W, according to recent ASCAT satellite data. South of the ITCZ and monsoon trough, winds are moderate or less. Seas of 13 to 17 ft prevail across most of the area north of 07N and west of 116W in NW swell. Elsewhere west of 101W, seas are 8 to 12 ft. East of 101W, seas are 5 to 7 ft. 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 by Sun afternoon. Elsewhere, the weakening cold front extending from 27N120W to 21N130W will dissipate tonight as it moves eastward. Another cold front will cross 30N140W tonight, reach from 30N124W to 26N130W Sun evening, then weaken by Mon evening as it approaches Baja California. Fresh to strong winds are expected north of 27N with this front. High pressure building across the northwest waters will enhance NE trades between the ITCZ and 20N, and to the west of 127W from Sun through most of the week, bringing fresh to strong winds and 8 to 12 ft seas to the area. $$ Hagen