000 AXPZ20 KNHC 250226 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0430 UTC Wed Oct 25 2017 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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 0215 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: Strong gale force northerly drainage winds are forecast to increase to slightly to minimal storm force overnight, with seas building to 25 ft downstream of the gulf waters near 14N95.5W by sunrise Wed. Strong gale conditions will then persist through Wed night, then the pressure gradient will relax with winds diminishing below gale force late Thu, and gradually diminishing to 20 kt or less on Fri. The resultant large NE swell will mix with long period NW swell, and long period cross-equatorial southerly swell, with a plume of seas 12 ft or greater developing across the EPAC waters within area bounded by a line from 16N95W to 07N92W to 06N100W to 10N102W to 16N95W on Wed night, with these seas gradually subsiding thereafter. The next gale event will occur on Fri night. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13N93W to 10N97W to 08N110W to 09N132W to 08N140W. Scattered moderate isolated strong convection is observed along the coast of Central America and along the eastern segment of the monsoon trough, roughly within 150 nm either side of a line from 05N78W to 12N89W to 13N101W. Similar convection is noted further W along the monsoon trough within 150 nm either side of a line from 08N108W to 10N136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: please see the special features section above for information on a strong gale/minimal storm event. Gulf of California: Strong NW winds with seas to 7 ft currently across the gulf waters N of 30N will continue through sunrise on Wed. A surface ridge extends into the area along 22N116W to 22N107W. Gentle N winds will accompany the ridge through early Sat. Mixing long period NW swell and cross-equatorial southerly swell results in 6 to 9 ft seas elsewhere across the open waters W of the Gulf of Tehuantpec event, or W of about 98W. These seas will gradually subside through Wed, with seas less than 8 ft on Thu, and less than 8 ft throughout the entire waters within 250 nm of the Mexican coast on Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate W winds and 5 to 8 ft seas will continue N of 09N tonight, with winds becoming northerly on Wed, and continuing through Thu. Fresh to strong winds southerly winds, and 7 to 10 ft seas, are expected S of 09N through Wed night. A tropical low is expected to develop off the Pacific coast of Costa Rica on Thu accompanied by a fresh to locally strong winds within about 150 nm of the low center. The low is expected to move northwestward through the upcoming weekend. REMAINDER OF THE AREA... A broad ridge dominates the EPAC waters N of 15N W of 115W accompanied by gentle to moderate anticyclonic flow and combined seas of 7 to 10 ft in mixing cross-equatorial southerly swell and long period NW swell. These seas will gradually subside t o less than 8 ft on Thu. A new batch of long-period NW swell in the form of 8 ft seas will arrive at 32N140W on Fri. Expect seas of 8 to 13 ft W of a line from 32N123W to 13N140W on Sat, before beginning to subside. $$ Nelson