000 AXPZ20 KNHC 052133 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Dec 05 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 1800 UTC surface analysis and satellite imagery through 2115 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the far southwestern Caribbean Sea to 08N79W to 07N90W to 07N100W and to 07N105W, where latest scatterometer data indicates that it transitions to the ITCZ to 10N116W to 10N125W to 07N133W and to beyond the area at 07N140W. Scattered moderate convection is within 60 nm south of the trough between 79W-81W, within 60 nm of the ITCZ between 124W-130W and within 30 nm of the ITCZ between 113W-115W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Earlier during the morning, an ASCAT pass depicted strong to near gale-force winds in the Gulf of Tehuantepec. Since then, winds there have diminished slightly, to mainly strong speeds. The earlier 8-11 ft seas with these winds are gradually lowering. An altimeter data pass downstream of the Gulf reveals peak seas of 9 ft. Seas to 8 ft have propagated well to the southwest of the Gulf of Tehuantepec region to near 11N100W. A large swath of fresh to strong northeast that surrounds the strong to near gale-force extends as far west as 1001. Light to gentle variable winds prevail across the offshore waters of Baja California under the influence of high pressure ridging, with seas of 4-6 ft due to long-period northwest swell. Seas are currently peaking to 8 ft near 30N120W. Across the remainder of the Mexican offshore waters outside of the Tehuantepec region, light to gentle winds and seas of 3-5 ft primarily to due a long- period northwest are noted. Gentle to moderate northwest winds are in the central and southern Gulf of California, with seas of 2-4 ft. Mainly light and variable winds with seas less than 2 ft dominate the northern part of the Gulf. For the forecast, a cold front that extends from southern Baja California to over northern Baja California will weaken as it advances east-southeastward toward the far northern Gulf of California and northwestern Mexico through tonight and dissipate early Tue morning. Seas of 6-9 ft in the wake of the front will subside tonight into Tue. Expect fresh to locally strong NW-N winds across the Gulf of California Wed night into Thu as high pressure builds across the Great Basin. Fresh to strong northerly winds are expected in the Gulf of Tehuantepec Wed through Fri night. Winds may reach to below gale- force early in Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong northeast to east winds are in the Gulf of Papagayo region, downwind to near 88W per a morning ASCAT pass. Peak seas with these winds are up to 7 ft. Light to gentle northeast to east winds are elsewhere north of the monsoon trough along 07N, with seas of 5-7 ft. based on an altimeter pass. Light to gentle south to southwest winds along with seas of 3-5 ft due to a northerly swell mixing with south swell are present to the south of the monsoon trough. Light to gentle south to southwest winds are present between Ecuador and the Galapagos Islands with seas of 3-4 ft. For the forecast, fresh to locally strong gap winds are expected in the Papagayo region mainly at night through Wed. Seas are forecast to remain below 8 ft. Elsewhere, little change in the marine conditions is forecast. Gentle to moderate winds will prevail across the offshore waters of Central America, Colombia, and Ecuador. Slight seas can be expected across most of the offshore waters through mid-week, except in the Papagayo region. Northwest swell generated from the Tehuantepec gap wind event will continue to move across the outer offshore waters of Guatemala and El Salvador today while subsiding. REMAINDER OF THE AREA... A cold front extends from far southern California south- southwestward to 30N116W and to 28N120W, where it becomes stationary to 26N127W to 24N135W and to 22N140W. Gentle to moderate northeast winds are behind the front, except for fresh northwest winds farther east near the Baja California peninsula. Seas behind the front are 8 ft in a long-period northwest to north swell. Elsewhere, high pressure controls the wind regime north of 16N and west of about 110W. The pressure gradient between the high pressure and lower pressures in the vicinity of the ITCZ supports an area of mainly fresh northeast to east trade winds from about 13N to 21N between 118W-128W and from 06N to 24N west of 128W. Seas within these areas of trades are 8 ft in northwest swell, except 8-9 ft in north swell west of 128W. An area of scattered moderate to isolated strong convection is observed on GOES-W visible and IR imagery well to the southwest of the Gulf of California from 13N to 19N between 115W-120W. This activity is being sustained by upper-level divergence occurring to the east of a broad upper mid to upper trough that is located to the west of the convection, with a base between 120W-130W and north of 20N. An ASCAT pass indicates that the convection has helped to make the fresh trade winds from 14N to 18N between 119W-122W more pronounced. For the forecast, the aforementioned stationary front will weaken through tonight and dissipate early Tue. High pressure will build across the area in the wake of the front. The associated gradient is expected to lead to moderate to fresh trade winds in the west-central waters. As the gradient tightens between strengthening of the high pressure and surface troughing that develops over the central waters near 126W by late Tue night, this is expected to increase the aforementioned fresh northeast trade winds to fresh to strong speeds at that time. The 8-9 ft seas may reach 10 ft with these winds. These marine conditions are expected to persist beyond Thu. The surface trough is forecast to slowly move westward possibly reaching near 140W over the upcoming weekend. $$ Aguirre