000 AXPZ20 KNHC 260920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Dec 26 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ..SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure extending south from Texas to southern Mexico is maintaining minimal gale force winds in the Gulf of Tehuantepec. A scatterometer pass at 0350 UTC showed a small area of 30-35 kt N winds north of 15N in the Gulf of Tehuantepec. The pressure gradient across the area will diminish today, and winds are expected to remain 20-30 kt in the Gulf of Tehuantepec the next two days. Model guidance indicates winds will reach minimal gale again on Thursday, then persist into the weekend as high pressure builds in the Gulf of Mexico. Refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 05N78W to 07N85W to 05N95W to 09N110W to 09N121W. The ITCZ continues from 09N121W to 08N128W to 07N140W. Scattered moderate isolated strong convection is noted from 07N to 10N between 110W and 118W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section above for details on the ongoing Gulf of Tehuantepec Gale event. A relatively static synoptic pattern associated with a nearly stationary subtropical high west of California and a surface ridge extending SE from the high will persist for several days, and gentle to moderate NW to N winds are expected west of Mexico through the end of the week. Seas will be generally 4-6 ft in offshore waters and 2-4 ft in the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate high pressure in the western Caribbean will continue to support fresh to strong NE winds from 09N to 11N east of 90W, including the Gulf of Papagayo, through early Thursday with seas to 7-9 ft in mixed NE wind waves and SW swell. Mainly gentle winds are expected elsewhere through Thu, with offshore seas generally 4-5 ft. REMAINDER OF THE AREA... Long-period NW swell is producing peak seas north of 25N and west of 135W around 9 ft. Seas will gradually diminish as the wave train continues moving SE. A trade wind disturbance near 12N114W drifting westward the next few days will induce fresh trade winds north of 10N between 115W and 125W through Thursday. The large area of NW swell will combine with wind waves created by this disturbance to produce an area of combined seas of 8 ft. $$ Mundell