000 AXPZ20 KNHC 121539 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1530 UTC Sun Nov 12 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 1200 UTC surface analysis and satellite imagery through 1430 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE: Gale-force winds continue in the Gulf of Tehuantepec. A high surface ridge along the Sierra Madre Oriental is maintaining a tight pressure gradient across the Isthmus of Tehuantepec. Model guidance suggests that the current synoptic pattern will remain favorable for gale-force N to NE gap wind flow until early Wednesday morning. The wind speeds will peak between 35 and 40 kt tonight through Mon night. Sea heights will range from 10 feet to 13 feet today, building to 16 feet tonight. POSSIBLE TROPICAL CYCLONE: A 1007 mb surface low is centered near 13N123W, moving west-northwestward. Numerous moderate to strong convection are from 10N to 17N between 121W and 130W. Gradual development of this system is possible through mid week, before upper-level winds become unfavorable for development. The chance of this low developing into a tropical cyclone through 48 hours is high. Please refer to the East Pacific Tropical Weather Outlook TWOEP for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N77W to 08N100W to 08N112W to the special features 1007 mb low near 13N123W to a 1007 mb low near 13N128W to beyond 11N140W. Aside from convection associated with the lows, Widely scattered moderate convection is from 08N to 13N, west of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for information regarding the ongoing Gulf of Tehuantepec gale. A ridge will dominate the waters W of Baja California the next several days. The surface pressure gradient W of Baja California will tighten slightly tonight through Tuesday as high pressure shifts eastward closer to the coast, resulting in fresh to locally strong NW winds N of 25N over the open Pacific waters, with seas building to near 8 ft. Winds over the Gulf of California during this same time period will increase to 10 to 15 kt. Elsewhere, mainly light to gentle winds and seas of about 4 to 5 ft will prevail the next several days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds, and seas of 4 to 6 ft, are generally expected N of the monsoon trough. Moderate to locally fresh S to SW winds and seas of 5 to 7 ft are forecast S of the monsoon trough through Tuesday. A slight increase in SW flow over the Gulf of Panama, to the south of the monsoon trough, may result in seas of 8 ft Tuesday through Thursday. REMAINDER OF THE AREA... Low pressure near 13N123W is discussed above in the special features section. The combination of long period NW swell propagating southeastward and the broad wind field associated with the special feature low is maintaining seas of 8 to 10 ft from about 08N to 23N, west of 115W. The swell field greater than 8 ft will decrease in areal coverage as the swell decays through Monday, however, the wind field associated with the special feature low will generate seas of 8 to 12 ft the next few days as the low tracks generally NW towards 20N135W. Another batch of NW swell of 8 to 9 ft will reach the NW waters Monday night, with these seas covering the far NW waters through much of the upcoming week. Elsewhere, mainly gentle to moderate winds and seas of 5 to 7 ft will prevail through the next several days. $$ Latto