000 AXPZ20 KNHC 170305 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Oct 17 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 0000 UTC surface analysis and satellite imagery through 0220 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N80W to 11.5N106W to 09.5N112W to low pres 1011 mb near 10.5N127W, then transitions to the ITCZ and continues to beyond 09N140W. Scattered moderate to strong convection is noted from 05.5N to 09.5N between 79W and 88W. Scattered moderate isolated strong convection is noted from 09N to 14N between 110W and 116W and from 07.5N to 13N between 123W and 132W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1022 mb well W of the the Baja California waters near 28.5N136W extends a ridge southeastward to the Revillagigedo Islands. The pressure gradient between this ridge and a trough over the Gulf of California is supporting moderate NW to N winds over the Baja California waters, where seas are in the 7-10 ft range in NW swell across the waters north of Cabo San Lazaro, and 6-9 ft southward to the Revillagigedo Islands. Light to gentle winds are across most of the Gulf of California, where seas are 3 ft or less. Another surge of strong northerly gap winds has begun across the Gulf of Tehuantepec, and extends to about 75 nm offshore, where seas are in the 5-7 ft range. Over the rest of the Mexican offshore waters, light to gentle winds and moderate seas 6 ft or less prevail. For the forecast, moderate northerly winds across the Baja California waters will weaken modestly through the weekend. NW swell moving through the Baja California waters will start to subside Thu. Low pressure will develop across the northern Gulf of California this evening through Fri inducing moderate to fresh SW to W gap winds across the Gulf basin, becoming strong across the north portions Thu night through Fri. A cold front will move southward through Baja Norte Fri afternoon and night and reach central portions of Baja on Sat before dissipating. Gap winds across the Tehuantepec region will increase to fresh to strong speeds tonight through early next week, pulsing to near gale- force each night Thu through Sat. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle onshore winds prevail north of 10N tonight, north of the monsoon trough. South of the monsoon trough, gentle to moderate SW to W winds prevail. Seas across the area waters are 4-6 ft in SW swell. For the forecast, light to gentle onshore winds are expected north of the monsoon trough through Sat, as low pressure attempts to organize across the western Caribbean. South of the monsoon trough gentle to moderate SW to W winds are expected through Thu then diminish slightly through early next week. Seas across the area waters will slowly subside through Fri as gentle to moderate winds persist, and small NW and SW swell dominates the area waters. New cross-equatorial S swell will enter the regional waters Fri night through Sun night, gradually increasing sea heights. Active convection accompanying a tropical wave across the west and northwest Caribbean will shift into the Pacific offshore waters from Nicaragua to Guatemala Fri night through Sun. ...REMAINDER OF THE AREA... High pressure of 1022 mb is centered near 28.5N136W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh to locally strong winds N of the ITCZ to near 18N and W of 125W, where seas are in the 10-12 ft range. Moderate to fresh trade winds are elsewhere south of 23N to the ITCZ, and west of 120W. Seas over these waters are 8-11 ft in NW swell. Light to gentle winds are in the vicinity of the high center, where seas are in the 8-9 ft range in decaying NW swell. Moderate northerly winds are east of the high center, and west of 115W, where seas are in the 8-10 ft range in NW swell. Light to gentle winds, and moderate seas are elsewhere N of the monsoon trough. Gentle to moderate winds, and seas of 5-7 ft prevail S of the ITCZ/monsoon trough. For the forecast, the aforementioned high pressure will move west of 140W early on Thu, then collapse as a cold front sinks into the region. The cold front will move into the northern waters Thu night and reach near 20N by Sat before dissipating. This will bring a brief period of moderate to fresh NE winds immediately behind the front Fri and Fri night, and moderate NE swell moving into the regional waters. South of the current high pressure, the associated anticyclonic wind flow will dominate the waters north of the ITCZ, producing moderate to fresh trade winds south of 22N and west of 130W through Thu night. Moderate to large NW swell spreading across regional waters is moving into the tropical Pacific waters tonight and will reach 110W by Fri morning. Otherwise, mainly gentle to moderate winds will prevail across the open waters through Thu. New southerly swell will cross the equator Fri through Sat. $$ Stripling