000 AXPZ20 KNHC 311410 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1415 UTC Tue Jan 31 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 1400 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong gales continue this morning with associated seas up to 12 to 13 ft. The gale force winds are expected to diminish early this afternoon. The associated north to northeast 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 about 90W and 110W, gradually subsiding through the week. Northerly winds will pulse to fresh to strong in the immediate Gulf of Tehuantepec tonight and again on Wednesday night, then may pulse to minimal gale force Thursday night through Saturday night. Eastern Pacific Gale Warning: A cold front extends from 30N135W to 21N140W which wraps into a 992 mb low pressure system near 34N145W. Recent scatterometer data showed fresh to strong southerly winds ahead of the front, while winds are increasing to gale force north of 28N west of the front. The combination of the strong winds and a component of longer period northwest swell is resulting in seas to 16 to 18 ft. A few showers may be active along and ahead of the front north of 28N. The front will reach from 30N130W to 19N140W by early Wednesday, then will weaken as it extends from 30N128W to 25N130W to 18N120W by Wednesday afternoon with winds diminishing below gale force then. The northwest swell will continue to propagate into the region, with seas reaching as high as 20 ft near 30N140W by this evening. The swell will decay gradually, but lingering combined seas of 12 to 15 ft will still be likely from 27N to 30N between 130W and 140W by late week. 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 04N89W to 01N98W to 02N93W to 03N102W. The intertropical convergence zone axis extends from 10N125W to 09N140W. No significant convection is noted with either of these features. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section above for gale conditions in and downstream of the Gulf of Tehuantepec. Weak high pressure just west of the area near 26N123W is supporting gentle to moderate breezes across area, to include the Gulf of California. Seas are mostly 3 to 5 ft in open waters. Winds and seas diminish further through mid week as the high pressure builds over the region. Looking ahead, a new round of northwest swell will move into the waters off Baja California Norte by late Thursday with seas 4 to 6 ft, building to 8 ft near Guadalupe Island by late Friday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulfs of Papagayo and Fonseca: Pulsing strong east to northeast winds are expected across the offshore waters from roughly 09.5N to 12N through the week, with the maximum seas building to 10 ft near 09N90W. The resultant northeast swell will continue to merge and mix with the northwest swell from the strong gap event in the Gulf of Tehuantepec. Gulf of Panama: A 90 nm wide band of fresh to locally strong n winds from the western Gulf of Panama to 05N81W are expected through mid-week, with seas building to 8 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... See special features section above for gale conditions in the northwest corner of the EPAC discussion area. Otherwise, an earlier pulse of northwest swell in the form of 7 to 10 ft seas are still observed west of 130W. The post-frontal swell to the northwest will propagate southeast across the open Pacific waters, merging with the current swell and reaching along 115W late this week. $$ LEWITSKY