000 AXPZ20 KNHC 211551 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Oct 21 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 1545 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec gale warning...The latest guidance suggests that the current minimal gale force winds will increase to 30 to 40 kt in about 12 hours, then diminish to 30 to 35 kt on Sat and continue into the early morning hours on Sun before diminishing below gale force by late sun morning. Minimal gale force conditions are expected to develop again late Mon and continue through Tue night. A 1006 mb stationary surface low is embedded in the monsoon trough near 13N115W with scattered moderate isolated strong convection currently observed within 180 nm over the s quadrant of the low. This low has the potential to become a tropical cyclone over the next few days, then increasing wind shear should inhibit development. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends off the Pacific coast of Nicaragua along 12N87W to 14N112W to low pres near 13N115W to low pres 10N131W to beyond 14N114W. Scattered moderate isolated strong convection is observed within 125 nm w of the surface low at 13N131W, elsewhere within 150 nm either side of a line from 12N87W to 11N108W and within 90 nm either side of a line from 13N117W to 10N123W. Scattered moderate and isolated strong convection is observed along the Pacific coast of Colombia within 90 nm of 06N78W, and over the Pacific coast of Mexico and extending offshore within 75 nm either side of a line from 18N103W to 15N109W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features for Gulf of Tehuantepec. A sub-tropical ridge axis extends from nw to se across the offshore zones w of central Mexico. Light to gentle nw flow with combined seas of 5 to 7 ft are expected through Sat night. Seas are forecast to then build to 7 to 9 ft across the waters n of 30N w of 117W on Sat night, and continue through Sun. Moderate to fresh nw winds across the northern Gulf of California will diminish this afternoon. Light and variable winds are expected elsewhere through early Sat, then light southerly flow expected across the entire gulf waters late Sat except increasing to moderate s winds across the northern gulf waters on Sat night and Sun. Light and variable winds expected elsewhere within 250 nm of the Mexican coast n of the Gulf of Tehuantepec through Sat, except moderate e to se winds are forecast beyond 200 nm on Sun and Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle w to nw winds are expected through Sat n of the monsoon trough which is meandering e to w along about 10N, while moderate sw flow is expected s of the monsoon trough Sat. The pressure gradient will relax on Sat night as the monsoon trough shifts s and extends from e to w along 07N. Combined seas of 4 to 7 ft, primarily in long-period sw swell is expected across the offshore waters for the next 3 to 5 days. REMAINDER OF THE AREA... A ridge extends from 32N140W to 17N110W. Moderate to fresh ne trades and 6 to 8 ft seas are expected through tonight s of the ridge and n of the relatively lower pressure within the monsoon trough. Winds and seas will continue to gradually diminish across the waters s of the ridge over the next couple of days. Nw swell is forecast to propagate e across the waters n of the ridge through Sat driving seas heights to 7 to 9 ft. $$ Nelson