000 AXPZ20 KNHC 270643 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Dec 27 2022 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over the Gulf of Mexico and the eastern north Pacific monsoon trough is supporting gales and rough seas across the Gulf of Tehuantepec. Strong winds reach as far as 300 nm downstream of the Gulf of Tehuantepec, with a large plume of wave heights in excess of 8 ft due to mixed swell extending more than 600 nm downstream. Gale conditions are expected to last through tonight, but gap winds and associated seas will diminish through mid week across the Gulf of Tehuantepec and downstream areas as the high pressure and cold airmass north of the area weakens and shifts eastward. Please read the latest High Seas Forecast issued by the the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 07N110W. The ITCZ extends from 07N110W to beyond 06N140W. Scattered moderate convection is noted from 07N to 10N between 117W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about a gale force gap wind event in the Gulf of Tehuantepec. A weak pressure pattern is supporting gentle to moderate breezes across Mexican offshore waters outside of the Tehuantepec area, with 4 to 6 ft wave heights primarily in NW swell. For the forecast, the gale force gap winds and rough seas will persist through the Gulf of Tehuantepec and adjacent offshore waters through tonight. Winds and seas will diminish off southern Mexico through Wed night as high pressure north of the area weakens and shifts eastward. Elsewhere, a cold front will move through Baja California Norte Thu, bringing fresh to occasionally strong winds to the northern Gulf of California Wed. Seas will build with increasing NW swell through Thu off Baja California, mainly north of Cabo San Lazaro. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E gap winds over the Gulf of Papagayo region extend offshore to 88W, with 5 to 7 ft seas. Moderate to fresh winds and seas of 8 to 10 ft are across portions of the Guatemala and El Salvador offshore waters due to swell generated from the gale force gap wind event in the Tehuantepec region. South of the monsoon trough, winds are gentle to moderate with seas to 5 ft. Otherwise, moderate to occasionally fresh northerly winds and seas to 5 ft are in the Gulf of Panama. For the forecast, fresh to strong NE to E gap winds will pulse in the Papagayo region and coast of Nicaragua through late Thu. Gentle to occasionally moderate winds will continue elsewhere for the next several days. Large NW swell generated from a gale force gap wind event across the Gulf of Tehuantepec region will continue in the waters off Guatemala through Tue. REMAINDER OF THE AREA... The pressure gradient between high pressure prevailing over the waters north of 20N and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh trade wind flow north of the ITCZ to about 20N. The associated wind waves are mixing with longer period NW swell dominating much of the area west of 130W, resulting in combined seas of 8 to 9 ft across the tropical waters along and north of the ITCZ west of 125W. Additional reinforcing NW swell is impacting the waters north of 25N and west of 135W with highest combined seas to 11 ft. For the forecast, wave heights will diminish through Thu south of 20N west of 110W as the large area of NW swell decays. Combined seas to 8 ft will prevail through mid week in persistent trade wind flow. North of 20N, reinforcing NW swell will maintain combined wave heights of 8 to 11 ft through Wed. East of 110W, NE swell from the Tehuantepec gap wind event will continue to mix with longer period southerly swell to support combined seas to 8 ft reaching as far as 105W through late Wed before seas subside. $$ Christensen