000 AXPZ20 KNHC 180357 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Jan 18 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 0345 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING: Strong high pressure ridging along the eastern slopes of the Sierra Madre Oriental Mountains of Mexico is forcing a continuation of gale force winds in the Gulf of Tehuantepec, with peak seas up to 14 ft. Winds and seas will continue to diminish tonight. The gale force winds and seas of 12 ft or greater should end after midnight tonight, local time. Afterward, winds will continue to gradually diminish and reach moderate speeds Thu afternoon. Northerly winds will increase again Thu night into Fri morning as the next gap wind event begins, increasing to gale force Fri night. Gales will then last through the weekend, with seas peaking near 13 or 14 ft on Sat. Please see the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from NW Colombia west-southwest to across northern Panama, and continues to 09N83W to 07N87W to 04N91W, where it transitions to the ITCZ and continues to 07N102W to 06N114W to 05N123W to 06N132W and to beyond 07N140W. Scattered moderate convection is within 60 nm south of the ITCZ between 124W-130W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the SPECIAL FEATURES section for details on a gap wind gale event presently in the Gulf of Tehuantepec region through tonight. Surface ridging present west of the Baja California offshore waters is anchored by high pressure of 1022 mb located west of Baja California Norte near 28N126W. This is generating moderate to occasionally locally fresh northerly winds over the offshore waters to the west of Baja California. Seas are 5-6 ft in this area. In the southern half of the Gulf of California, NW winds are moderate with seas of 1-3 ft. The northern Gulf of California is experiencing gentle winds along with 1-2 ft seas. Elsewhere in the SW Mexican offshore waters, winds are moderate or weaker with seas in the 3-5 ft range. The exception is well offshore the Mexican states of Oaxaca and the southeastern part of Guerrero, where fresh NE to E winds and seas to 7 ft extend well downstream from the Gulf of Tehuantepec gap wind event. For the forecast, moderate to locally fresh NW to N winds over the Baja California offshore waters will diminish to gentle speeds Thu morning as the high pressure mentioned above slides eastward over the area. The next Gulf of Tehuantepec gap wind event is expected to begin Fri, and continue through the weekend, with gale force winds possible Fri night through Sun night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong northeast winds are occurring in the Gulf of Papagayo region with seas to around 9 ft. Fresh north winds are in the Gulf of Panama, where seas are up to around 5 ft. Winds are gentle or weaker elsewhere, except for moderate northeast winds well offshore of Guatemala. Seas of 7-9 ft in northwest to north swell are currently affecting the waters offshore Guatemala due to a gale force gap wind event occurring in the Gulf of Tehuantepec. Elsewhere, seas are 3-5 ft. For the forecast, fresh to strong northeast to east winds will pulse across the Gulf of Papagayo region through Mon. These strong winds will expand in areal coverage tonight while reaching near gale force as seas build to 9 ft. The area of strong winds will then contract a bit Thu afternoon through Fri afternoon. The area of strong winds should then expand more in coverage again Sat night through Mon while reaching near gale force as seas build to 8-10 ft. Elsewhere, moderate to fresh north to northeast winds in the Gulf of Panama will change little through Sun, then increase to fresh to strong speeds late Sun. Otherwise, rough seas in northerly swell will continue to affect the Guatemala offshore waters through tonight due to a strong gap wind event currently affecting the Tehuantepec region. Rough seas are expected once again in the Guatemala offshore waters Sat through Sun due to the next Gulf of Tehuantepec gap wind event. ...REMAINDER OF THE AREA... Seas of 8-10 ft are west of 129W due to long-period northwest swell. A 1022 mb high center is analyzed near 28N126W. The pressure gradient between this feature and the ITCZ supports fresh trade winds from the ITCZ to near 15N and west of about 116W. Seas in this area are 8-10 ft due to northeast wind waves mixed with long-period northwest to north swell. North of 22N and east of 129W, under the high pressure, winds are gentle and seas are 5-7 ft. South of the ITCZ, moderate to fresh southeast winds and 7-8 ft seas prevail. For the forecast, the 8-10 ft seas in the northwest part of the area will slowly subside through late tonight. A cold front is expected to enter the northwest part of the area on Thu, extend from 30N132W to 24N139W early on Fri, then weaken and dissipate Fri night. Fresh to strong south to southwest winds are expected through early Fri morning in advance of the front, north of about 24N and west of 128W. These winds will then move north of 30N Fri morning. This system will cause seas to increase again over the northwest part of the area to 10-15 ft Thu into Fri night, before seas subside to 8-11 ft early on Sat. Elsewhere, conditions are not forecast to change much through Sat. $$ Aguirre