545 AXPZ20 KNHC 041003 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Nov 04 2021 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 0945 UTC. ...SPECIAL FEATURES... Low pressure of 1007 mb is located over the far eastern Pacific west of Costa Rica near 09N89W. Latest satellite imagery shows that its associated convection continues to show signs of organization. This convection consist of the numerous moderate to isolated strong type intensity within 120 nm of the center in the SE quadrant and within 60 nm of the center in the SW quadrant. Atmospheric conditions are expected to remain conducive for additional development of this low pressure system, and a tropical depression is likely to form within the next couple of days while the system moves generally westward away from the coast of Central America and well to the south of the coast of southeastern Mexico. This system has a high chance of becoming a tropical cyclone during the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure that will build southward from the Gulf of Mexico toward southeastern Mexico and lower pressure south of Mexico is forecast to initiate a gale force gap wind event over the Gulf of Tehuantepec beginning on Fri night. This event is expected to last into next week, with peak winds of 35 kt and seas forecast to reach a maximum of around 12 ft. Northeast swell produced by this upcoming event will propagate downstream of the Gulf of Tehuantepec, with seas of 8 ft or greater reaching as far south of 09N and west to near 108W by early next week. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from low pressure of 1010 mb near the coast of Colombia at 11N75W to across northern Costa Rica, then southwestward to low pressure near 09N89W 1007 mb to 11N100W to low pressure near 12N106W 1010 mb to low pressure near 12N115W 1012 mb and to 08N125W. The ITCZ extends from 08N125W to 08N130W to low pressure near 09N140W. Scattered moderate to isolated strong convection is seen from 11N to 14N between 99W-106W, within 60 nm of the trough between 96W-99W and within 60 nm south of the trough between 113W-116W. Scattered moderate convection is within 30 nm of the trough between 106W-110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO Please see the Special Features section above for details on an upcoming Gulf of Tehuantepec gale force gap wind event. High pressure of 1022 mb is centered near 28N130W with an associated ridge extending southeastward west of Baja California. The pressure gradient between this area of high pressure and a surface trough over the Gulf of California is supporting is supporting gentle to moderate winds west of the Baja California peninsula as well as over the Gulf of California. Strong north to northeast winds are funneling through the Gulf of Tehuantepec. Light to gentle winds prevail elsewhere. Seas up 8 ft are over the Gulf of Tehuantepec, 5-8 ft west of Baja California, and 4-6 ft over the remainder of open waters off Mexico. Seas are 1-3 ft over the Gulf of California. The strong Gulf of Tehuantepec gap winds will increase to near gale force late tonight, then reach gale force Fri night through Mon. Moderate to fresh northwest winds offshore of Baja California will continue through Fri. Light to gentle winds will continue across the Gulf of California through the period. Low pressure of 1007 mb located well southeast of the forecast waters near 09N88W is likely to develop into a tropical cyclone during the next couple of days and move westward well to the south of the coast of Central America and southeastern Mexico. It is expected to bring increasing winds and seas to the offshore waters downwind of the Gulf of Tehuantepec region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Please see the Special Features section above for more on the potential for tropical cyclone development. Fresh to strong winds and seas to 8 ft are noted around the low, which is centered near 09N88W. Outside of winds and seas associated to the low pressure system, light to gentle winds are elsewhere north of the monsoon trough. Gentle to moderate winds prevail south of the monsoon trough. Seas of 5-6 ft prevail across the discussion waters. Moderate to fresh winds will prevail over the Gulf of Papagayo through Thu, with light to gentle winds elsewhere north of the monsoon trough. Gentle to moderate southwest winds will persist south of the monsoon trough today. Low pressure southwest of the Papagayo region will move generally westward through the period. It is likely to form into a tropical depression during the next couple of days well to the south of the coast of Central America. Expect scattered to numerous showers and thunderstorms over the offshore waters of Costa Rica and Panama through Thu. South- southwest swell will continue over the forecast waters through the next few days. REMAINDER OF THE AREA... High pressure of 1023 mb is centered over the northern waters near 29N129W. Light to gentle winds are noted in the vicinity of the high center. The pressure gradient between this area of high pressure and lower pressure within the monsoon trough and in the vicinity of the ITCZ is supporting gentle to moderate winds elsewhere over the waters north of the ITCZ and monsoon trough. Gentle to moderate winds prevail south of the monsoon trough and ITCZ. Seas are in the 6-8 ft range over the waters north of 10N and west 115W, reaching to 12 ft over the NW waters, except for higher seas up to 16 ft north of 27N and west of 138W as were highlighted by the latest altimeter data pass over that part of the area as a large set of NW swell propagates into the area. Seas in the 5-6 ft range prevail elsewhere. The northwest swell will spread southeastward maintaining seas 8 ft or greater over much of the waters north of 09N and west of a line from 30N116W to 14N122W and to 09N140W through Fri before it gradually decays through the weekend. A cold front may brush the far northwest waters on Sun preceded by fresh to strong southwest to west winds and seas to near 10 ft. $$ Aguirre