219 AXPZ20 KNHC 150942 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jan 15 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 0840 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Light and variable winds across the Gulf of Tehuantepec region tonight through Sat, will give way abruptly to gale-force gap winds late Sat night that are expected to continue through Sun night. This will occur as another cold front moves across the western Gulf of Mexico with high pressure building over the Gulf of Mexico and eastern Mexico behind it. Seas are expected to reach a peak of about 14 ft with this upcoming event. Please see the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from northern Colombia near 11N74W southwestward to 04N83W to 06N90W to 05N95W. The ITCZ extends from 05N95W to 07.5N117W to beyond 07.5N140W. No significant convection is noted at this time. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A Gale Warning is in effect for the Gulf of Tehuantepec, with gale conditions expected to commence late Sat night. Please see the Special Features section above for details. High pressure centered northwest of the region is supporting a weak pressure gradient across the Baja California offshore waters tonight. Deep layered upper level low pressure west of 120W continues to support surface troughing between 118W and 128W, which continues to deflect high pressure to the west of the area. Recent scatterometer data indicated gentle to moderate northerly winds prevailing across the Baja offshore waters to 18N. Seas are 6-7 ft in W-NW swell, except to 8 ft across the waters west of Isla Guadalupe. Moderate to locally fresh NNW winds prevail over the central and southern Gulf of California, while light to gentle winds are over the northern part of the Gulf. Seas of 3-4 ft are in the central portion and 4-5 ft in the southern portion. Light to gentle W to NW winds are elsewhere across the open waters off Mexico from Cabo Corrientes to Puerto Angel, where seas are 4-6 ft. A cluster of showers and thunderstorms developed early tonight across coastal portions of Mexico, from Puerto Angel to near Acapulco, and has gradually shifted westward overnight. This weather will continue through sunrise before diminishing. Marine conditions have become relatively tranquil across the Gulf of Tehuantepec region in recent hours, with light to gentle winds. Seas there have diminished to 2-4 ft in a west to northwest swell. An area of 6-7 ft seas due to mixed northeast and northwest swell is located well to the southwest-west of the offshore waters and extends to 108W. This area of mixed swell will decay late today. Fresh northwest winds in the central and southern Gulf of California will increase to strong Sat and Sat night, then diminish back to fresh Sun. Peak seas will reach 5-7 ft late Sat night through Sun morning. W-NW swell will continue to move through the waters offshore of Baja California through Mon. Northerly gales are expected across the Tehuantepec region prior to sunrise Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR High pressure across the Gulf of Mexico is supporting fresh NE to E gap winds across the Gulf of Papagayo region. Seas there are in the 4-6 ft range. Gentle to moderate winds are noted elsewhere north of 05N. Overnight scatterometer data showed moderate to locally fresh northerly winds across the Gulf of Panama, and extending S-SW to near 06N. Seas are 3-5 ft outside of the Gulf of Papagayo region, mainly due to S to SW swell. High pressure north of the area will support fresh northeast to east gap winds over the Gulf of Papagayo region through early Sat, then strengthen fresh to strong late early Mon morning through the middle part of next week. Seas in the Gulf of Papagayo region will increase 6-8 ft early Tue into the middle part of next week. Gentle to moderate winds will prevail elsewhere north of 04N, pulsing to fresh in the Gulf of Panama through the middle part of the upcoming week. Light to gentle winds will continue south of the trough described under the ITCZ/Monsoon section. REMAINDER OF THE AREA Moderate west to northwest swell is propagating through the north and west parts of the area west of a line from Baja California Norte to 03N140W, where seas are 7-10 ft, as measured by overnight satellite altimeter passes. Seas elsewhere are 7-8 ft west of 115W. An elongated and deep-layer upper-level low pressure system is presently stationary between 120W-130W from 15N to 32N, where a broad inverted surface trough is noted 122W-123W to the north of 16N. Satellite imagery shows scattered light isolated moderate convection to the east of the upper low from 27N TO 33N between 118W and 123W. Tropical moisture continues to be advected northward on the eastern side of the deep-layer low, roughly between 118W-124W and reaches as far north as 32N. The pressure gradient between the surface trough and high pressure located to the northwest continues to promote moderate to locally fresh NE winds to the north and west of the trough. The upper level low is forecast to lift northward this weekend, allowing for mainly gentle north to northeast winds to persist west of the surface trough. Gentle to moderate easterly winds prevail elsewhere north of the ITCZ to 18N, and west of about 110W, except for mainly northeast winds west of 128W. The W-NW swell is forecast to gradually decay over the upcoming weekend. The trough is forecast to drift W through Sun, while weak low pressure develops near 31N128W. This will maintain a weak pressure gradient across the regional waters and fairly tranquil marine conditions. Looking ahead, a new trough is expected to develop north of the ITCZ along 128W by Tue, and meander northward through mid week. Increasing winds and seas will be seen near the trough and north of 20N during this time, as the pressure gradient increases. $$ Stripling