000 AXPZ20 KNHC 091526 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1526 UTC Fri Dec 9 2016 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 Warning: The gale began earlier this morning over the Gulf with seas likely building above 10 ft late this morning. The gradient will continue to tighten this evening and tonight as sustained winds increase to around 45 kt. Max seas will build to 16-18 ft by early Saturday. Gale conditions will persist until 1200 UTC on Sunday, then pulse to 25-30 kt each night from Sunday night through Tuesday night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N84W to 08N100W to 07N109W. The ITCZ continues from 07N109W to 08N130W to beyond 09N140W. Scattered moderate convection is present from 06N to 13N between 94W and 115W, as well as from 06N to 11N between 115W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: The pressure gradient between surface troughing along the Mexico coast and high pressure over the east Pacific will continue to support fresh to strong northwest winds over the Gulf of California mainly south of 28N through late this evening. Then, the pressure gradient will relax somewhat with winds decreasing to moderate to fresh late tonight. The area of high pressure to the northwest will weaken late Saturday, allowing for gentle to moderate winds to prevail Saturday night through Thursday. A gale over the Gulf of Tehuantepec will continue until Sunday morning. Please see the special features section above for more details. Elsewhere, ridging dominates the offshore Pacific waters of Mexico with a 1026 mb high centered near 29N126W. Aside from the Tehuantepec event, light to gentle winds will prevail south of 17N through the forecast period. Fresh to occasionally strong northwest winds west of Baja California will continue through Sunday night before decreasing to moderate to fresh as the ridge weakens slightly. From 17N north to Mazatlan, moderate to locally fresh northwest winds will prevail. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong offshore winds east of 90W will continue to pulse mainly during the overnight hours this weekend. Seas will top out around 8 ft during these pulsing events. A surface trough over the central Caribbean will cross Central America early Monday. Some of the global guidance indicates possible low pressure development along the trough axis as it moves westward from zones PMZ113 to PMZ111 on Tuesday and Wednesday. Mostly light to gentle N to NE winds, and combined seas of 3 to 5 ft, are occurring elsewhere N of the monsoon trough, which is expected to meander between 07N and 10N through Wednesday. Light to moderate southwest flow is observed from 05N to 09N, with combined seas of 3 to 5 ft in southwest swell. Moderate to fresh southerly flow is expected south of 05N through Wednesday. REMAINDER OF THE AREA... 1026 mb high pressure is centered near 29N126W with a ridge axis extending southeast from the high to near 15N105W. Gentle to moderate north-northwest flow is expected northeast of the ridge axis this weekend and moderate to fresh trades will prevail south of the ridge and ridge axis, north of the ITCZ. Fresh to occasionally strong NE winds and combined seas of 8 to 9 ft will generally prevail from 07N to 17N W of 120W north of the ITCZ through Sunday. Low pressure approaching the eastern Pacific from the northwest will weaken the ridge on Tuesday and Wednesday, allowing winds and seas in this area to subside. $$ LATTO