000 AXPZ20 KNHC 230847 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Sep 23 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 0940 UTC. ...SPECIAL FEATURES... A Gale Warning remains in effect for the Gulf of Tehuantepec tonight into Thu morning. High pressure building across the eastern slopes of the Sierra Madre Mountains, in the wake of an early cold front, currently moving across the Gulf of Mexico, will support minimal gale force winds tonight into Thu morning. Seas of 8 to 13 ft are occurring in the Tehuantepec region. Winds and seas are forecast to diminish later this morning but the gap wind event will continue through Sun night. Please, refer to 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. ...TROPICAL WAVES... The axis of a tropical wave is along 115W from 06N to 19N, moving west at 10 to 15 kt. Scattered moderate convection is from 07N to 15N between 110W and 120W. The axis of a tropical wave is along 124W from 06N to 20N, moving west at 10 to 15 kt. A 1009 mb low pressure is E of the wave axis near 17N122W. Scattered moderate convection is from 15N to 20N between 120W and 126W. Development of this system during the next day or so, if any, is likely to be slow. After that time, this system is forecast to move over cool waters and into an environment of stable air and strong upper-level winds, which should inhibit further development. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation. Please, refer to the latest Tropical Weather Outlook, at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 10N86W to 10N100W to 12N116W. The ITCZ begins near 11N124W and continues to beyond 10N140W. Aside from the convection associated with the waves, scattered moderate convection is across the Panama, Costa Rica and Colombia offshores, N of 07N between 90W and 103W, and from 05N to 11N W of 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong to gale force winds are in the region of Tehuantepec with seas to 9 ft building to 11 ft tonight. A ridge continues to dominate the offshore forecast waters of Baja California producing gentle to moderate NW to N winds with seas in the 4 to 6 ft range. Gentle to moderate northerly winds are also in the Gulf of California with seas to 3 ft. Light to gentle variable winds are across the SW Mexico offshore waters with seas in the 3 to 5 ft range. For the forecast, gale force winds in Tehuantepec are forecast to diminish below gale force by Thu morning and then gradually diminish to moderate to fresh by Sun. See the Special Features section for further details. Surface ridging will continue to dominate the offshore forecast waters of Baja California supporting mainly gentle to moderate NW to N winds through Sun. Light to gentle winds will dominate over the SW Mexico offshore waters. Gentle to moderate winds are expected in the northern Gulf of California through Fri, and in the central and south parts of the Gulf through tonight. After that, mainly light and variable winds are expected across the entire Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate southerly winds will prevail across the offshore waters of Costa Rica, Panama, Colombia and Ecuador through Thu, then mainly light to gentle winds will prevail. Mainly light and variable winds are forecast across the offshore waters from Guatemala to northern Costa Rica through Sat. Cross equatorial SW swell will reach again the forecast area toward the end of the week, building seas to 6-7 ft between Ecuador and the Galapagos Islands during the upcoming weekend. REMAINDER OF THE AREA... The northern forecast waters remain under the influence of a surface ridge anchored on a 1026 mb high pressure located near 35N138W. The pressure gradient between the ridge and a low pres center near 16N121W supports an area of moderate to locally fresh NE winds roughly from 10N to 25N W of 120W with seas to 7 ft. Winds across this area will diminish over the weekend. $$ Ramos