000 AXPZ20 KNHC 191036 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Dec 19 2024 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 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The passage of a cold front and a high pressure in its wake will enhance northeasterly winds across the Gulf of Mexico. This is going to sustain near gale to gale-force gap winds in the Gulf of Tehuantepec through early Sunday morning. Seas under the strongest winds will peak between 10 and 12 ft. As the high shifts eastward, this should allow winds and seas in the Gulf of Tehuantepec to gradually subside Sunday afternoon and evening. Please see the latest NWS High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough curves southwestward from the west coast of central Costa Rico to 04N94W. An ITCZ continues westward from 04N94W to 05N122W, then from 05N105W to 05N125W to beyond 140W at 06N. Scattered moderate convection is seen south of the monsoon trough from 05N to 07N between 77W and 85W. Widely scattered showers are found near the ITCZ from 05N to 09N between 120W and 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section about a Gale Warning at the Gulf of Tehuantepec. A surface ridge extending southeastward from a 1024 mb high near 33N127W to near the Revillagigedo Islands is supporting light to gentle winds and seas of 6 to 8 ft in decaying NW swell across the Baja California offshore waters. Gentle to moderate NW winds with 2 to 4 ft seas are present at the Gulf of California. Gentle northerly winds and seas at 4 to 6 ft in mixed moderate swell exist at the central and southern Mexico offshore waters, except at the Gulf of Tehuantepec. Outside the Gale Warning area, fresh to strong northerly winds with 6 to to 10 ft are evident offshore from Oaxaca State in southern Mexico. For the forecast, strong to gale-force gap winds and very rough seas in the Gulf of Tehuantepec are expected to continue through early Sun morning, then gradually subside Sun afternoon and evening. Light to gentle winds at the offshore waters west of Baja California will increase to between moderate and fresh this weekend through early next week. Moderate to fresh NW winds in the central Gulf of California will diminish to between gentle and moderate by Thu. Moderate NW swell west of Baja California will become large late this weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A broad surface ridge over the northwestern Caribbean Sea is causing fresh to strong NE winds and seas of 4 to 7 ft in the Gulf of Papagayo region. Moderate northerly winds with seas at 3 to 5 ft exist at the Gulf of Panama. Elsewhere south of the monsoon trough and between Ecuador and the Galapagos, gentle to moderate southerly winds and 4 to 6 ft seas in moderate S to SW swell prevail. For the forecast, fresh to strong NE winds will continue in the Papagayo region through this weekend, before decreasing early next week. Moderate to fresh northerly winds are expected in the Gulf of Panama through Mon. Gentle to moderate winds between Ecuador and the Galapagos Islands will continue through Fri, then mainly gentle afterward. ...REMAINDER OF THE AREA... Convergent trades are triggering scattered moderate convection south of the Revillagigedo Islands from 10N to 13N between 105W and 113W. Moderate to fresh SW winds and 8 to 10 ft seas are evident to the east of a cold front northwest of a line from 30N134W to 26N140W. A surface ridge extending southeastward from a 1024 mb high near 33N127W to near the Revillagigedo Islands is supporting gentle to moderate northerly winds north of 18N and west of 120W. Seas in this area range from 6 to 8 ft in moderate to large NW swell. The gradient between this ridge and the ITCZ to the south is sustaining moderate to fresh trades with 7 to 9 ft seas over the tropical waters from the ITCZ to 18N and west of about 110W. Gentle to moderate trades and seas of 5 to 7 ft in mixed moderate swells are found elsewhere south of the ITCZ west of 92W. For the forecast, the southern end of the aforementioned cold front will cross 140W later this morning and sustain fresh to strong winds with 10 to 13 ft seas northwest of a line from 30N132W to 26N140W. As the cold front weakens this evening, both winds and seas will gradually subside tonight and Fri morning. Afterward, another cold front will cause a similar episode from Fri evening through Sat. NW swell related to the second cold front will cause seas north of ITCZ to rise to between 10 and 18 ft by Sun. NE winds from the ITCZ and 18N, west of 128W are expected to become fresh to strong by Sun. Little change is expected elsewhere. $$ Chan