000 AXPZ20 KNHC 182202 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Dec 18 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The strong to near gale-force winds ongoing over the Gulf of Tehuantepec are forecast to reach gale-force speeds tonight and continue through late Sat night. A a cold front is forecast to move across the Gulf of Mexico followed by a high pressure tightening the pressure gradient across the Gulf of Tehuantepec. Please see 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N83W to 06N92W, where it transitions to the ITCZ and continues to 06N125W. A trough extends from 10N127W to 06N128W. The ITCZ resumes west of this trough at 06N130W and to beyond 06N140W. Scattered showers are depicted from 05N to 09N between 136W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1028 mb is analyzed northwest of Baja California Norte near 35N127W. A ridge extends from the high east- southeastward across the Baja Peninsula. The related gradient has relaxed some allowing for winds to decrease to light to gentle with seas 5 to 8 ft in northwest swell, except for higher seas of 8 to 10 ft west of Baja California Norte. In the Gulf of California, recent scatterometer data depicted fresh to locally strong winds over the area with seas 2 to 4 ft. Strong to near gale-force northerly winds are in the Gulf of Tehuantepec region along with seas to 8 ft. Light to gentle winds and moderate seas in mixed swell prevail across the southwestern Mexican offshore zones. For the forecast, light to gentle winds over the offshore waters N of Cabo San Lazaro will continue through Fri night. Winds in these areas are forecast to increase to moderate to fresh speeds during the weekend and continue within that range through the beginning of next week. A new set of northwest swell is forecast to approach Baja California late this afternoon before subsiding Thu morning. Fresh to locally strong northwest winds in the central Gulf of California will diminish some to fresh speeds tonight, to mostly moderate speeds from Thu to Sat night and to light to gentle speeds through the middle of the week. Strong to near gale-force gap winds ongoing in the Gulf of Tehuantepec region are forecast to reach gale-force tonight and continue through late Sat night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast winds are pulsing to strong speeds in the Gulf of Papagayo region with seas 4 to 7 ft. These winds are generally driven by the gradient associated to high pressure that extends into the northwestern Caribbean Sea from the Gulf of Mexico. Moderate to fresh northerly winds are pulsing in the Gulf of Panama, where seas are 3 to 5 ft. Elsewhere south of the monsoon trough and between Ecuador and the Galapagos, southerly winds are light to gentle in speeds, and seas are 4 to 6 ft in a south to southwest swell. For the forecast, fresh to strong northeast winds will continue to pulse in the Papagayo region through the next few days along with moderate seas. Moderate northerly winds pulsing to fresh speeds will remain in the Gulf of Panama through Sun. Gentle to moderate winds between Ecuador and the Galapagos Islands will continue through Fri, then mainly gentle speeds will prevail afterward. ...REMAINDER OF THE AREA... High pressure of 1028 mb is analyzed near 35N127W. A ridge extends southeastward from this high across the subtropical waters, which is supporting gentle to moderate northwest winds west of the Baja Peninsula offshores along with seas 8 to 11 ft reaching to near 120W. The gradient between the ridge and relatively lower pressure found to its south is sustaining fresh to locally strong trades over the tropical waters west of about 124W, where seas are in the 8 to 12 ft range. A surface trough that is analyzed along 127W from 06N to 10N has helped to sustain the fresh to locally strong winds. Moderate to fresh trades are elsewhere south of the ITCZ and north of the ITCZ west of 120W. For the forecast, mostly fresh northeast to east winds and seas to 11 ft will be present west of about 123W through Thu as the gradient in place fluctuates little. The aforementioned trough will continue westward though Thu while losing its identity. A cold front is expected to approach 30N140W tonight, preceded by fresh to strong southerly winds. The leading edge of a large set of northwest swell is forecast to outrun the front reaching from near 30N132W to 27N140W late tonight. By Thu seas will build to 9 to 14 ft in the area of these winds. A reinforcing cold front will skirt the northwest forecast waters Fri night preceded by fresh to strong winds and seas to 19 ft. Yet another cold front may approach 30N140W on Mon, preceded by fresh to strong southwest to west winds, and like the previous one, have the leading edge of a large set of northwest out ahead of it. Latest wave model guidance from the GFS depicts seas to about 20 ft near 30N and west of 134W on Mon. $$ KRV