000 AXPZ20 KNHC 291548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Jan 29 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A strong gale force event is currently in progress with the northerly winds forecast to increase to 35 to 45 kt this evening with seas building to a max of 22 ft downstream of the Gulf of Tehuantepec near 14.5N95W tonight. The associated n swell will mix with both long period southwesterly cross-equatorial swell and long period northwesterly swell resulting in a large area of combined seas of 8 ft or greater reaching the equator between 93W and 103W, and as far sw as 10N112W on Tue before beginning to subside. A cold front is approaching the far nw portion of the discussion area with scattered moderate convection currently observed within 30 nm either side of a line from 30N138W to 29N140W. Strong southerly winds are already observed n of 27N between 138W and 140W with combined seas of 11 to 13 ft partially due to long period nw swell preceding the front. Remnant mixed swell with 7 to 11 ft seas surround these strong winds across the waters w of a line from 32N130W to the equator 120W. The cold front will reach from 31N138W to 28N140W early Mon with the southerly winds increasing to near gale force ahead of the front with seas building to 10 to 14 ft. The remnant mixed swell will have then subsided some, but 7 to 10 ft seas will still continue from 09N to 32N w of 129W. The cold will extend from near 32N133W to 21N140W early Tue, with strong s winds within 120 nm e of the front. The post frontal westerly flow across the discussion waters from 27N to 30N between 136W 140W will increase to minimal gale force of 25 to 35 kt, with seas building 16 to 21 ft in the associated nw swell. 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 sw off the Pacific coast of Colombia from 04N78W to a 1009 mb surface low pressure at 01N81W, with the trough then turning nw to 03N95W where scatterometer winds indicate that the ITCZ forms and continues wnw through 06N120W to 06N140W. Only isolated moderate to strong convection is observed within 30 nm either side of a line from 05N77W to 01N82W to 04N94W. Surface troughs are analyzed from 07N115W to 13N112W and from 06N133W to 11N129W with only isolated moderate convection flaring occasionally along the troughs. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for gale conditions in and downstream of the Gulf of Tehuantepec. Gulf of California: Strong to near gale force nw winds across the gulf waters n of 24N this morning are forecast to diminish to a strong breeze across the waters just n of 30N early Mon, then diminish to a fresh breeze by late Mon morning, then further diminish to 20 kt or less late Mon. Seas will subside accordingly to less than 8 ft. Light to gentle breezes are then expected through mid week. Fresh to locally strong ne winds across the waters adjacent to the nw Baja Peninsula early this morning will diminish to a moderate to fresh breeze this afternoon and a moderate n breeze tonight. Seas of 3 to 6 ft in nw swell are forecast elsewhere n of the Tehuantpec event, with little change then expected through mid week. Another round of large nw swell in the form of 8 ft seas or greater will arrive near 30N120W on Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulfs of Papagayo and Fonseca: Fresh to locally strong ene winds are expected to diminish late this morning downstream of Papagayo, then resume this evening and briefly increase to near gale force late tonight as strong conditions develop across the outer waters of the Gulf of Fonseca. Max seas of 11 ft are forecast near 10N88W early Tue as the associated ne swell merges with nw swell propagating se from the strong gap event in the Gulf of Tehuantepec. Gulf of Panama: Fresh to locally strong n winds expected through early Tue when strong winds are forecast to reach as far s as 03.581W with seas building to 9 ft. Light to gentle winds, and combined seas of 3 to 5 ft, are occurring elsewhere outside of the swells originating near the gap events. REMAINDER OF THE AREA... Remainder of area covered in the special features section. $$ Nelson