000 AXPZ20 KNHC 150334 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0240 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 08N78W to 06N85W. The ITCZ extends from 06N87W to 05.5N95W to 07N120W to 10N134W to beyond 07N140W. 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 well northwest of the region is supporting a weak pressure gradient across the Baja California offshore waters tonight. Deep layered upper level low pressure continues to support surface troughing west of the area between 120W and 130W, and has been blocking high pressure from building into the area. Afternoon scatterometer data indicated fairly light north winds prevailing north of 20N. However, the surface troughing west of the area has begun to drift NW, allowing some ridging to begin across the offshore waters this evening, with gentle to moderate NW to N winds now prevailing across the Baja waters. Seas are 5-7 ft in west to northwest swell. 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 slightly higher seas of 4-5 ft are in the southern portion. Light to gentle W to NW winds are elsewhere over the open waters off Mexico, where seas are 5-6 ft. 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 3-6 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 beyond 108W. This area of swell will decay late Sat. 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. West-northwest swell will propagate southeastward across 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, except moderate to locally fresh northerly winds across the Gulf of Panama, and extending S-SW to near 03N. Seas are 4-5 ft outside of the Gulf of Papagayo region, mainly due to S to SW swell. High pressure north of the area will support fresh to strong northeast to east gap winds over the Gulf of Papagayo region through early Sat, then again late Sun night into early Mon, and change little through the middle part of next week. Seas in the Gulf of Papagayo region will change little 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 7-9 ft. Seas elsewhere are 7-8 ft west of 115W. An elongated and deep-layer upper-level low pressure system is presently stationary between 121W-135W from 19N to 32N, where a broad inverted surface trough is noted from near 28N120W to 16N124W. Satellite imagery shows scattered moderate convection to the east of the upper low from 26N TO 30N between 116W AND 121W. Abundant tropical moisture continues to be advected northward on the eastern side of the deep-layer low, roughly between 118W-124W and reaching just beyond 30N. The pressure gradient between the surface trough and high pressure located to well to the northwest continues to promote moderate to locally fresh northeast winds to the north and west of the trough. The upper level low is forecast to lift north and northeast this weekend allowing for mainly gentle north to northeast winds to exist west of the surface trough. Gentle to moderate easterly winds prevail elsewhere north of the ITCZ to 16N, and west of about 110W, except for mainly northeast winds west of 130W. The west to northwest swell is forecast to gradually decay over the upcoming weekend. The trough is forecast to dampen out through Sun as it lifts northward. Otherwise, fairly tranquil marine conditions are forecast across the waters this weekend as the pressure gradient remains weak to moderate and regional seas are dominated by the decaying northwest swell. $$ Stripling