000 AXPZ20 KNHC 170333 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Nov 17 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 0330 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec gale warning: minimal gale force n to ne winds will continue through maximum drainage late tonight with seas building to about 13 ft mainly downstream of the gulf waters near 14.5N95.5W. Expect the n winds to diminish throughout the day on Thu and leaving a narrow swath of 20 to 25 kt winds from around sunset Thu through sunrise Fri. Only moderate to fresh n winds are forecast from late Fri morning through late Fri afternoon when peak heating will produce another 20 to 25 kt surge around sunset, with the winds quickly increasing throughout Fri night behind a strong Gulf of Mexico cold front, with the flow reaching minimal gale force again late Fri night. Strong gale conditions of 40 to 45 kt are expected across a large swath late Sat night with minimal storm force conditions winds a possibility although current guidance indicates a 45 kt maximum. Gale conditions will end late Tue morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends w off the Pacific coast of northern Costa Rica at 10.5N86W to 09N95W to 11N104W to 10N111W to 09N121W where scatterometer winds indicate an ITCZ forms and continues w to 13N133W to beyond 11N140W. Small clusters of isolated moderate to occasionally strong convection is observed within 240 nm either side of the monsoon trough and ITCZ. ...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 winding down near 19N113W and is estimated at 1011 mb. Fresh to strong nw winds with combined seas of 8 to 15 ft are observed n of 29.5N w of the northern Baja Peninsula and southern California. These strong winds will diminish to 20 kt or less on Thu with the resultant large nw swell, in the form of 7 to 11 ft seas, propagating s across the waters w of the entire Baja Peninsula through Fri, and then quickly subsiding on Fri night, with seas of 4 to 6 ft forecast w of Baja by late Sat. Light and variable winds are observed across the Gulf of California to the s of 29.5N, while moderate to fresh southerly winds are noted to the n of 29.5N. The southerly winds across the northern waters will clock to the sw and increase to 15 to 25 kt along 30N late tonight ahead of a cold front, with strong to near gale force northerly winds expected briefly in the wake of the front on Thu morning. Expect moderate nw to n winds across the entire Gulf of California by Fri morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate to locally fresh ne winds are expected across and just downstream of the Gulf of Papagayo late each night through sunrise each morning for the next several days. The cyclonic circulation associated with a broad area of low pressure developing in the sw Caribbean is expected to produce strong nocturnal n to ne flow across the Gulf of Papagayo as early as Sun morning and develop again late Sun and Mon nights. Light to gentle nw to n winds and combined seas of 3 to 6 ft are occurring elsewhere n of the monsoon trough which has been meandering e to w along about 09N, while moderate to 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. REMAINDER OF THE AREA... A surface high is centered n of the area near 36N139W. NW swell continues to propagate se with seas of 8 to 11 ft w of a line from 32N116W to 12N40W. The southern extent of seas 8 ft or greater will reach from the central Baja Peninsula to 13N140W on Thu night and then begin to subside. In the meantime, the pressure gradient between this high and the relatively lower pressure in the vicinity of the ITCZ is supporting fresh to locally strong ne to e trade winds to the north of the ITCZ. The high will shift e allowing a cold front to move into the far nw waters late Thu night accompanied by a fresh to strong sw to w to nw wind shift to the n of 31N, and a 15 to 20 kt wind shift along the front elsewhere n of 28N. Another round of large nw swell will follow the front with seas of 8 of 16 ft. This second round of nw swell will reach the northern Baja Peninsula on Sun evening. $$ Nelson