000 AXPZ20 KNHC 120308 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Oct 12 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 0300 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 94W north of 04N to across the Gulf of Tehuantepec. It is moving westward at 10-15 kt. Scattered moderate to isolated strong convection is along the wave axis from 09N to 11N between 93W and 95W. Similar convective activity is noted ahead of the wave from 04N to 08N between 96W and 100W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends across western Panama and Costa Rica near 10N84W to 12N94W to 15N105W to 11N120W to 08N140W. Scattered moderate to isolated strong convection is noted from 07N to 11N between 81W and 90W, and from 08N to 10N between 112W and 117W. A cluster of moderate to isolated strong convection is from 07N to 10N W of 137W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front extends from the northern Gulf of California across Baja California Norte to 27N120W to 28N130W to 30N135W. A tight pressure gradient between building high pressure behind the front and relatively lower pressure in the western U.S. has resulted in fresh to strong NW to N winds behind the front, mainly between 117W and 124W. In the Gulf of California, gentle to moderate southerly winds prevail along with seas of 4 to 5 ft over the southern part of the Gulf. Farther south an area of 8 to 9 ft seas in a westerly wind flow is noted from 11N to 17N between 98W and 107W. Fresh to strong SW to W winds are noted along the coast of Oaxaca, including the west part of the Gulf of Tehuantepec. These winds could be associated with a broad area of low pressure over SE Mexico. For the forecast, the aforementioned cold front will sweep across the rest of central Baja California and the central Gulf of California through tonight while weakening. Fresh to strong NW to N winds and a swell event follow the front, building seas to 9 to 12 ft N of 26N between 116W and 133W by Thu morning, with the highest seas near 30N120W. In the Gulf of California, moderate to fresh south to southwest winds are expected through Thu. High pressure will then settle in over the area through early next week. Fresh to strong southwest to west winds that are just south and southwest of the Gulf of Tehuantepec will diminish by early Thu afternoon. The first Gulf of Tehuantepec gap wind event of this fall season is expected to begin on Sun afternoon, with fresh to strong north to northeast winds lasting well into next week as winds gradually increase. There is a possibility for these winds to reach gale-force Mon and Mon night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Mostly light and variable winds are north of about 07N, and gentle to moderate south winds south of 07N. Seas are generally 4-6 ft across the region due a southerly swell. For the forecast, mainly light to gentle winds will continue north of of the monsoon trough, with gentle to moderate winds south of it. Long-period southerly swell will continue to propagate across the offshore forecast waters with seas of 5 to 7 ft mainly between Ecuador and the Galapagos Islands through early Fri. ...REMAINDER OF THE AREA... A ridge dominates the forecast waters N of 15N and W of 120W. The associated pressure gradient is allowing for generally gentle to moderate northeast to east trade winds over these waters. Seas with these winds are 5 to 6 ft per recent altimeter data. Elsewhere, north of the monsoon trough and ITCZ light to gentle northeast to east winds are present with seas of 4 to 5 ft. Gentle to moderate south to southwest winds are south of the monsoon trough. Seas there are 5 to 6 ft due to southerly long- period swell. For the forecast, high pressure over the area will gradually shift eastward and weaken through Fri as a cold front that is currently moving across the central waters continues to push southward while weakening, and another cold front enters the northwest part of the area while also weakening. A rather extensive set of northwest swell will follow in behind this front bringing seas of 8-10 ft to the far northwest waters starting Fri. $$ GR