000 AXPZ20 KNHC 270315 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Jan 27 2017 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 0315 UTC. ...SPECIAL FEATURES... EPAC Gale Warning: A surface trough has formed across the tropical waters from roughly 07N139W to 16N133W with strong to near gale force ne to e winds from roughly 10N to 26N between 123W and 140W. A surface low is forecast to soon form along the trough near 14N135W, with 30 to 40 kt gale force winds developing within about 420 nm n of the low on Fri and persist into Fri night. Guidance suggests the low will open back to a trough as it passes 140W on Sat. EPAC Gale Warning: A quasi-stationary surface ridge extends from 32N130W to 14N100W. Strong ne winds will develop across the offshore waters along the northern Baja Peninsula early Fri, with gale force winds expected along the Baja coast from 27.5N to 29.5N on Fri afternoon with a swatch of strong to near gale force winds extending sw from the gale area to near 24N117W on Fri night. Pulsing gale winds will continue through Sat morning. Gulf of California Gale Warning: Strong to near gale force nw winds will expand across the entire gulf waters tonight. The pressure gradient will further tighten on Fri morning with embedded swaths of gale force winds developing by early Fri afternoon, and continuing through Sun morning. With the nnw wind trajectory, expect frequent gusts to gale force surrounding the smaller swaths of 35 kt. Seas are forecast to build to about 13 ft in the open fetch waters along 26N. The pressure gradient should begin to relax on Sun afternoon. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for additional details on these warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N139W to 16N133W with scattered moderate convection observed within 120 nm e of the trough axis. Scatterometer winds indicate that the ITCZ forms near 03N91W and extends w to 03N100W, then turns nw to 09N125W to 08N137W. Scattered moderate isolated strong convection is noted along the ITCZ from 10N to 14N between 122W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for gale conditions along the Baja Peninsula and across the Gulf of California. Long period nw swell in the form of 6 to 9 ft seas are observed across the open waters w of 110W. These seas will be reinforced by another round of seas of 11 to 13 ft propagating se across the waters offshore to the n of 28N tonight through Fri night. Mixing sw and nw swell resulting in seas of 4 to 7 ft are expected between 96W and 110W tonight into Fri, then build from the n again on Fri night into Sat. Gulf of Tehuantepec: strong to near gale force northerly winds are expected in and downstream of the gulf tonight with seas building to 10 ft near 15N95W early Fri. The north winds will diminish to a fresh breeze on Fri afternoon, then increase to a strong breeze again briefly late Fri night. A stronger gap wind event is forecast beginning on Sat evening with gale conditions Sat night through sunrise on Tue. The strongest winds of 30 to 40 kt area expected on Mon evening with seas building to 18 ft near 14N96W. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh ene nocturnal winds expected early tonight with strong winds forecast briefly around sunrise of Fri. Stronger gap events are forecast on Fri night through Tue nights, with seas building to about 10 ft downstream of the gulf waters near 10N88W on Tue. Gulf of Panama: Fresh n nocturnal winds expected each night through the upcoming weekend, except strong winds are forecast briefly overnight. Light to gentle winds, and combined seas of 3 to 5 ft, are occurring elsewhere until swells from the gap events develop over the upcoming weekend. REMAINDER OF THE AREA... See special features section above for a gale warning near 15N135W. Otherwise, large NW swell with combined seas to 12 ft currently across the discussion waters w of 93W will gradually subside. Strong southerly winds and large seas will spread e over the waters n of 22N w of 138W beginning on Sun, ahead of a cold front reaching 32N140W late Tue. $$ Nelson