000 AXPZ20 KNHC 252145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Jan 25 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... ...GALE WARNING... A surface trough IS developing across the tropical waters from roughly 10N140W to 15N135W with strong ne to e winds within about 120 nm n of the trough. A surface low is forecast to form along the trough near 13N136W on Thu, with strong to near gale force winds developing mainly over the n semicircle, and expanding northward to about 760 nm. The gradient will support gale force winds within about 240 nm n of the low on Thu night into Fri evening when the low passes to the w of 140W. A surface ridge will extend across the area from 32N130W to 17N104W on Fri with strong ne winds developing across the offshore waters along the northern Baja Peninsula early Fri, with minimal gale force winds expected along the Baja coast from 27.5N to 29.5N on Fri afternoon. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 04N90W to 08N118W to 05N128W to 07N140W, but currently lacks significant convection. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends se across the far offshore waters w of 110W. Long period nw swell in the form of 8 to 11 ft seas, is propagating se across the open waters w of 110W. These large seas are forecast to subside to 7 to 10 ft by late Thu, then be reinforced by another round of seas of 11 to 13 ft propagating se across the waters n of 28n on Thu night through Fri. Strong to near gale force winds will develop ne of the ridge axis along the Baja Peninsula with a small area of gale winds in offshore zone PMZ011 beginning on Fri afternoon, and continuing through Sat evening as mentioned in the special features section above. Mixing sw and nw swell resulting in seas of 5 to 8 ft are expected between 96W and 110W through Thu, then building from the n again on Fri night. Gulf of California: Fresh nw to n winds currently across the entire gulf waters are expected to increase with locally strong nw winds across the central gulf waters tonight. The gradient will tighten some more throughout Thu with strong nw flow expected across the entire gulf waters on Thu night, with embedded swaths of near gale force winds by late Thu night and continuing through early Sat. Guidance suggests that minimal gale conditions will develop across the central gulf waters on Sat evening and across the northern gulf waters late Sat night. Seas are forecast to build to 11 ft in the open fetch waters along 26N on Fri night into Sat, with the pressure gradient relaxing on Sun. Gulf of Tehuantepec: strong northerly winds are expected to begin on Thu evening with seas building to 11 ft downstream of the gulf near 15N95W early Fri. The north winds will diminish to a fresh breeze Fri afternoon, then briefly increase to locally strong on Fri evening. A stronger gap wind event is forecast beginning on Sat night with gale conditions then continuing through Mon evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh ene nocturnal winds expected tonight and on Thu night. A strong gap event is forecast on Fri through Mon nights, with seas building to about 9 ft downstream of the gulf waters near 10.5N87.5W. Gulf of Panama: Fresh n nocturnal winds expected each night through the upcoming weekend, except very brief strong winds are forecast tonight. Light to gentle winds, and combined seas of 3 to 5 ft, are occurring elsewhere. REMAINDER OF THE AREA... See special features section above. Otherwise, large NW swell with combined seas to 12 ft across the discussion waters w of 93W are being reinforced by another round of nw swell. $$ Nelson