000 AXPZ20 KNHC 182158 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Fri Nov 18 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 2145 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec gale warning: A 20 to 25 kt northerly surge will begin around sunset this evening, with the winds quickly increasing throughout tonight reaching minimal gale force around midnight. Further strengthening will occur on Sat with strong gale conditions of 40 to 45 kt expected across a large swath on Sat evening with seas building to 19 ft near 14.5N95W. Minimal storm force conditions winds are a possibility, although current guidance still indicates a 45 kt maximum near the surface. High profile vessels should expect storm force winds at 30 meters. Gale conditions will end Mon morning with near gale force continuing through sunrise on Tue before diminishing. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends nw off the Pacific coast of Costa Rica at 09N85W to 11N94W, then turns sw to 10N106W, then turns nw again through the base of a trough at 12N114W, then sw to 09N127W where scatterometer winds indicate an ITCZ forms and continues nw to beyond 11N140W. Scattered moderate isolated strong convection is observed within 90 nm OF 08.5N86W, within 150 nm either side of a line from 09N95W to 09N103W to 12N108W, from 06N to 13N between 110W and 118W, and within 90 nm either side of a line from 09N118W to 09N126W to 15N135W to 13N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section for a gale warning in the Gulf of Tehuantepec. The remnant circulation of former tropical cyclone Tina is still winding down near 19N115W and is estimated at 1011 mb. Light to gentle ne winds with combined seas of 7 to 10 ft are observed n of 19N w of 111W. These seas will subside to 4 to 6 ft forecast w of Baja by late Sat. Large nw swell in the form of 7 to 9 ft seas will reach 30N120W on Sun morning, reach the n coast of the Baja Peninsula late Sun building 8 to 12 ft, extend s across all the offshore waters w of Baja on Mon night, then subside to less than 8 ft on Wed. Moderate to locally fresh nw winds across the entire Gulf of California will diminish to light to moderate on Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate to locally fresh n to ne winds are expected across and just downstream of the Gulf of Papagayo tonight. The cyclonic circulation associated with a broad area of low pressure in the sw Caribbean is expected to produce a strong nocturnal n to ne flow across the Gulf of Papagayo late Sat, Sun and Mon nights. Light to gentle n winds and combined seas of 3 to 6 ft are occurring elsewhere n of the monsoon trough which continues to meander e to w along about 09N, while moderate to locally fresh sw flow is observed s of the monsoon trough, with combined seas of 4 to 7 ft primarily in long-period sw swell. Little change forecast through the upcoming weekend. The conditions along the Pacific coast of Central America surrounding the Gulf of Papagayo early next week are dependent on the strength and position of the the broad low pressure in the SW Caribbean that has the potential to become a tropical cyclone. REMAINDER OF THE AREA... A cold front along 32N132W to 27N140W will reach from 32N126W to 22N140W on Sat, from 32N122W to 22N130W on Sun, and reach the northern Baja Peninsula on Sun. Another round of large nw swell will follow the front with seas of 8 of 16 ft initially, but subsiding to 7 to 11 ft by the time they reach the northern Baja Peninsula on Sun night. $$ Nelson