000 AXPZ20 KNHC 100945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Feb 10 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Minimal gale force northerly winds of 30 to 35 kt extend sw to near 14N95.5W with maximum seas of 14 ft near 15N95.5W. The gale conditions will end by early afternoon, but the resultant n swell will propagate sw to near 10N100W today before beginning to subside with seas less than 8 ft on Sat afternoon. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends along the Pacific coast of Colombia and Equador from 04N77W to 03.4S83W. Scatterometer winds indicate that the northern hemisphere ITCZ forms at 04N120W and extends wsw to 03N140W. Scattered moderate convection is observed within 90 nm either side of a line from 04.5N88W to 00N104W, and within 30 nm either side of a line from 08N124W to 07N120W. ...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: A light to moderate nw breeze will persist through this morning, then winds will become light and variable this afternoon and continue through Sat night. Seas of 4 to 7 ft expected across the open waters w of the Baja California Peninsula this morning. Seas will increase from the nw this afternoon as long period northwest swell arrives in the form of 6 to 8 ft seas which will spread se across the waters n of 25N on Sat night, and n of 22N briefly on Sun before subsiding on Sun night. Light winds and 3 to 6 ft seas forecast elsewhere across the EPAC waters n of the Gulf of Tehuantepec through Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong to near gale force ene winds are forecast within 120 nm either side of a line from 11.5N86W to 10N91.5W through Sat morning, with seas building to 7 to 10 ft. The resultant ne swell will mix with long period cross equatorial sw swell, with seas of 8 ft or greater propagating sw to near 06N100W on Sat evening before beginning to subside. The pressure gradient will relax on Sun and Mon with winds diminishing to 20 kt or less by late Tue morning. Gulf of Panama: A 45 nm wide band of fresh to locally strong n winds extend ssw from the western Gulf of Panama to near 05N81W. The pressure gradient will further tighten tonight with strong to near gale force n to ne winds forecast across the Pacific waters from 04N to 08.5N between 78.5W and 82.5W, with seas building to a max of 11 ft near 05.5N81W early Sat. The pressure gradient will relax on Sat night with the winds 20 kt or less and seas less than 8 ft by Sun afternoon. Light to gentle winds, and combined seas of 3 to 6 ft, are occurring elsewhere outside of the swells originating near the gap events. REMAINDER OF THE AREA... A cold front is currently analyzed from 32N124W to 21N140W with only a 10 kt sw to w wind shift near the front. Scattered showers are observed n of 28N within 150 nm of the front. Large post frontal nw swell results in 10 to 14 ft seas w of the front, with 8 to 11 ft seas elsewhere w of line from 32N121W to 06N140W. The front will weaken as it continues eastward and is expected to become diffuse along 32N119w to 20N140W tonight. The nw swell will decay below 12 ft tonight, but seas in excess of 8 ft will persist west of 120W into early Sat before beginning to subside. Combined seas of 8 to 10 ft will spread into the nw waters to the n of 23n w of 136W on Sat night, and cover the waters n of 14n w of 135W on Sun as strong southerly winds develop n of 28N w of 137W. $$ Nelson