000 AXPZ20 KNHC 122121 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Dec 12 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N87W to 07N94W. The ITCZ continues from 07N94W to 09N100W to 10N127W to 07N140W. Scattered moderate convection is from 11N TO 15N between 119W and 128W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Fresh to strong north winds continue today north of 15N with max seas to 8 ft. Residual high pressure over southern and eastern Mexico will continue to weaken, allowing winds to diminish to around 20 kt by Tuesday evening. The pressure gradient is expected tighten again Thursday afternoon to produce gale force winds Thursday evening through Friday. Moderate to fresh northwest winds in offshore waters north of 20N will become gentle to moderate through Thursday with 4-6 ft seas. Light to gentle north winds will prevail S of 17N through Wednesday. Gentle to moderate northwest winds will prevail between 17N and Mazatlan through Wednesday, becoming light Thursday and Friday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A 1010 mb surface low moving off the Pacific coast of Nicaragua will wove westward through Thursday night. Global models show modest development of the low through Tuesday, then weakening Wednesday and becoming a weak low west of 100W. Latest global model forecasts show associated winds remaining 25 kt or less. REMAINDER OF THE AREA... A broad surface ridge over the NW forecast waters is anchored by a 1024 mb high centered near 28N127W. Gentle to moderate north- northwest flow is expected east of the high through Wednesday. Moderate to fresh NE winds are situated between the ridge and the ITCZ, generally from 10N to 20N W of 125W. Low pressure with a trailing frontal boundary northwest of the area will briefly stall near the far northwest waters on Wednesday and introduce winds of 20 to 25 kt and seas 8 to 10 ft. Then reinforcing cold air will push the front east-southeastward across the northern waters Thursday and Friday. NW swell generated behind the front will cause seas to build N of 26N and W of 120W to 10 feet by Friday morning. $$ Mundell