000 AXPZ20 KNHC 060338 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Nov 6 2023 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 0330 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A ridge continues to extend across the eastern slopes of the Sierra Madre Mountains. This is supporting minimal gale force northerly winds across the Tehuantepec region with maximum seas of 12 ft. Seas generated from this gap wind event are propagating well away from the Gulf of Tehunatepec, with seas of 8 ft or greater reaching as far south as 09N98W based on an altimeter pass from this afternoon. Winds are forecast to diminish below gale force by Mon evening, but fresh to strong gap winds and moderate to rough seas will persist until Tue night. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Recently downgraded Post-Tropical Cyclone Pilar is centered near 10.7N 114.8W at 06/0300 UTC, moving west-northwest at 7 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Convection has nearly ended around the center of the low, with some isolated convection noted within 75 nm north of the center. Peak seas are currently near 14 ft and is expected to continue subsiding through tonight and into Mon. The post-tropical cyclone will move WNW to N during the next few days. Additional weakening is forecast, and the remnant low is forecast to dissipate in a couple of days. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Pilar NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 09N84W to 08N108W then continues SW of Post-Tropical Cyclone Pilar near 08N116W to 06N124W. The ITCZ extends from 06N124W to beyond 08N140W. Scattered moderate convection is from 05N to 11N between 79W and 86W, from 06N to 17N between 98W and 119W and from 05N to 09N between 135W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on the Gulf of Tehuantepec Gale Warning. A ridge continues to dominate the Baja California offshore waters. This is producing gentle to moderate winds across the Baja California offshores with seas 4 to 7 ft. Scattered thunderstorms are noted near the coast of Baja California Sur. Moderate to fresh winds are also likely occurring south of Cabo San Lucas where the 7 ft seas are noted. Elsewhere, light to gentle winds are noted across the rest of the Mexico offshore waters, including the Gulf of California. Seas range 4 to 6 ft within mixed swell, and seas are up to 3 ft in the Gulf. For the forecast, the gale force winds in the Tehuantepec region are expected to persist through Mon. Associated rough seas will continue to propagate over the waters off eastern Oaxaca and western Chiapas Mon into Tue. The winds and seas will continue to gradually diminish through Tue night off southern Mexico. Looking ahead, a weakening cold front will approach Baja California Norte on Tue followed by fresh to locally strong NW to N winds and moderate to rough seas. These marine conditions will reach the waters north of Punta Eugenia Tue night into Wed. Seas are forecast to propagate across the waters north of Cabo San Lazaro later on Wed. At the same time, high pressure situated over the Great Basin of the United States will bring fresh to strong northerly winds across the Gulf of California Wed through Fri, particularly over the N part of the Gulf. Seas are forecast to build to 4 to 6 ft within these winds. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate S-SW monsoonal winds prevail across the offshore waters S of 09N while mainly light to gentle winds are noted N of 09N. Seas range 6 to 8 ft across the offshore waters of Guatemala W of 93W due to the Tehuantepec gap wind event. Seas of 3 to 5 ft are observed elsewhere within mostly S swell. Scattered thunderstorms are occurring along the coast of the Central American offshore waters and along the Colombian coast. For the forecast, expect moderate to rough seas off Guatemala through tonight due to swell generated in the Tehuantepec region by gale force winds. Winds will pulse to fresh across the Gulf of Papagayo Tue night through Thu morning. Gentle to moderate winds and slight to moderate seas in primarily in SW swell will persist elsewhere. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Post-Tropical Cyclone Pilar. A cold front extends across the NW waters from 30N134W to 28N140W. Moderate to locally fresh N winds are noted behind the front with seas to 7 ft. Elsewhere, a ridge extends across the region north of 17N and W of 115W. The pressure gradient between the ridge and lower pressures near the ITCZ supports an area of fresh to locally strong winds N of the ITCZ and monsoon trough to 22N and W of 120W. Seas are to 8 to 9 ft within these winds. South of the ITCZ and monsoon trough, gentle to moderate winds prevail with seas to 7 ft within mixed swell. For the forecast, Pilar will become a remnant low and move to 11.2N 115.7W Mon morning, 11.9N 116.7W Mon evening, 12.9N 117.9W Tue morning, 13.9N 119.1W Tue evening, and dissipate Wed morning. Elsewhere, the above mentioned cold front will reach from 30N130W to 26N140W by Mon morning, and begin to weaken as it approaches Baja California Norte on Tue morning. A new swell event will follow the front building seas of up to 11 ft on Mon. The swell noted around the fresh winds north of the ITCZ will also persist through the next few days. As the front moves SE a large area of 8 to 9 ft seas will dominate most of the waters N of 07N W of 115W by Wed morning as it merges with the swell along the trade wind zone. Strong high pressure will follow the front bringing an increase in the trade wind flow Mon night through at least Thu. $$ AReinhart