000 AXPZ20 KNHC 100320 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Dec 10 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Scatterometer data at 1630 UTC showed gale force winds north of 15N in the Gulf of Tehuantepec. A tight pressure gradient analyzed across the region tonight is expected to support sustained winds to around 45 kt. Max seas will build to 17-18 ft by early Saturday. Gale conditions will persist until Sunday morning, 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 10N84W to 06N91W to 07N97W. The ITCZ extends from 07N103W to 09N116W to 07N128W to 08N140W. Scattered moderate convection is from 08N to 12N between 111W and 122W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: A weakening pressure gradient between a surface trough along the Mexico coast and high pressure over the east Pacific will continue to support fresh northwest winds over the Gulf of California S of 27N tonight. High pressure northwest of the area will weaken by late Saturday, allowing gentle to moderate winds to prevail through mid-week. Ridging dominates elsewhere in offshore waters of Mexico with a high centered near 29N125W. Aside from the Tehuantepec high wind event, light to gentle winds will prevail S of 17N through the forecast period. Fresh to occasionally strong northwest winds west of Baja California will continue through Sunday night, then become moderate to fresh as the ridge weakens slightly. From 17N north to Mazatlan moderate to 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. Max seas will be around 8 ft during the event. An easterly wave in the central Caribbean will cross Central America Monday. Some model guidance indicates low pressure development along the wave axis as it moves west of the coast Tuesday through Wednesday. But lacking consensus between models, favor keeping it a strong trough or weak low in forecast grids. Light to gentle north to northeast winds and combined seas of 3 to 5 ft are occurring north of the monsoon trough, which is expected to meander between 08N 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... High pressure centered near 29N126W extends with a ridge axis southeast to near 21N110W. 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 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 15N W of 120W through Sunday. Low pressure approaching the far northwest waters will weaken the ridge on Tuesday and Wednesday, allowing winds and seas in this area to subside. $$ Mundell