000 AXPZ20 KNHC 170945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jan 17 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 0930 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING: Strong high pressure is building southward along the eastern slopes of the Sierra Madre Oriental Mountains of Mexico, and while at the same time relatively lower pressures are present south of Mexico. This synoptic set up is producing gale force northerly winds in the Gulf of Tehuantepec. Gale force winds of 40 to 45 kt and seas peaking to around 16 ft will affect the region through early this evening. Afterward, winds will gradually diminish and reach gentle to moderate speeds by Thu afternoon. 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 northwest Colombia to across central Panama and to 08N82W to 05N90W, where it transitions to the ITCZ and continues to 05N90W to 05N110W to 07N125W to 06N135W and to west of the area at 06N140W. Scattered moderate convection is within 120 nm south of the ITCZ between 115W-123W, and also within 60 nm north of the ITCZ between 112W-122W. ...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. Gale force winds are ongoing in the Gulf of Tehuantepec as were depicted in an overnight ASCAT-B data pass. Surface ridging present west of the Baja California offshore waters is anchored by high pressure of 1023 mb located west of Baja California Norte near 28N126W. This is generating moderate to occasionally fresh northerly winds over the offshore waters to the west of Baja California. Seas are in the 6-7 ft range in this area. In the southern half of the Gulf of California, NW winds are moderate to fresh with seas of 3-4 ft. In the northern Gulf of California, moderate northwest winds along with 1-3 ft seas remain there. Elsewhere in the SW Mexican offshores, winds are moderate or weaker with seas in the 3-5 ft range due to a long- period south to southwest swell. For the forecast, a tight pressure gradient in southeastern Mexico due to strong high pressure surging southward over eastern Mexico and combining with relatively lower pressures to the south is producing gale force northerly winds in the Gulf of Tehuantepec. Gale force winds up to 40 to 45 kt and building seas to 16 ft will affect the region through this evening. Afterward, winds will gradually diminish and reach gentle to moderate speeds by Thu afternoon. Elsewhere, moderate to locally fresh NW to N winds over the Baja California offshore waters will diminish to gentle speeds Thu morning. Moderate to locally fresh winds will continue in the southern half of the Gulf of California through early this morning. Looking ahead, another Gulf of Tehuantepec gap wind event is likely to begin by Fri and continue through the weekend, with gale force winds possible beginning Fri 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 6 ft. Fresh north winds are in the Gulf of Panama, where seas are up to around 5 ft. Winds are gentle or weaker elsewhere along with seas of 3-5 ft. For the forecast, fresh to strong northeast to northeast to east winds will pulse across the Gulf of Papagayo through the rest of the week and into the upcoming weekend. These winds are expected to reach near gale force tonight and also during the weekend. The area of strong winds in the offshore Papagayo region will expand some in coverage today, with developing rough seas to 9 ft by tonight. These winds expand more in coverage Sun through Mon. 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 forecast for the Tehuantepec region. ...REMAINDER OF THE AREA... Seas of 8-12 ft are north of 23N and west of 134W due to long- period west to northwest swell. A 1023 mb high center is analyzed near 28N126W. The pressure gradient between this feature and the ITCZ supports fresh to locally strong trade winds from the ITCZ to near 15N and west of about 116W. Seas in this area are 8-11 ft due to northeast wind waves mixed with long-period northwest to north swell. North of 22N and east of 130W, under the high pressure, winds are gentle and seas are 5-6 ft. South of the ITCZ, mostly moderate southeast winds and 7-8 ft seas prevail. For the forecast, the 8-12 ft seas in the northwest part of the area will slowly subside through early Thu. A cold front is expected to enter the NW part of the area on Thu, then weaken early Fri as it reaches from near 30N132W to 24N140W. Fresh to strong south to southwest winds are expected through Thu night in advance of the front, north of about 25N and west of 130W. These winds then shift to north of 30N late Thu night. Seas in the northwest part of the area will increase again to a range of 9-14 ft Thu into Fri night before shifting to north of 30N early on Sat. Elsewhere, conditions are not forecast to change little through Fri night. $$ Aguirre