000 AXPZ20 KNHC 130318 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 318 UTC Tue Feb 13 2018 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 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A cold front has stalled across the western half of the Gulf of Mexico, reaching into the west portion of the Bay of Campeche. High pressure ridging southward across eastern Mexico and the adjacent waters, to the east of the Sierra Madre Oriental range, is supporting gale force winds offshore and across the Gulf of Tehuantepec. Winds will peak around 40 kt tonight and again on Tue night. The gale force winds will likely diminish early Thu. Gulf of Papagayo Gale Warning: Fresh to near gale force offshore winds will expand in coverage tonight, with fresh to strong winds offshore of the Gulf of Fonseca also. Winds will increase further to minimal gale force offshore of the Gulf of Papagayo Tue night through at least Wed, with fresh to near gale force thereafter into the upcoming weekend. Downstream seas will build to 8-11 ft Tue night through Thu. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details on both gale warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the Colombia and Panama border near 07N77W TO 03N99W. The ITCZ axis extends from 03N99W to 06N113W to 10N122W, then resumes from 11N124W to 08N140W. Scattered moderate convection is noted within an area bounded by 09N117W to 08N116W to 07N117W to 07N119W to 07N119W to 09N119W to 09N117W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on a developing gale warning in the Gulf of Tehuantepec. A weakening cold front extends from southern Nevada to across Baja California norte and offshore to near 28N120W. A pre-frontal trough is over the far northwest corner of the Gulf of California, with fresh to strong southerly winds ahead of it. Seas are likely close to 8 ft despite the relatively limited fetch area. Winds will diminish early Tue as the front and trough weaken. Light and variable winds and seas of 2 ft or less will then prevail across the Gulf of California through mid-week, becoming northerly and increasing to moderate to fresh by the end of the week as the pressure gradient tightens across the region. Elsewhere across the open Pacific offshore waters of Mexico, light to moderate winds will prevail through the week, increasing to near fresh offshore of Cabo Corrientes by the end of the week. Seas will mainly be 4-6 ft in mixed southwest and northwest swell. An inverted trough may lift northward across the offshore waters of Baja California by mid-week, with weak low pressure possibly and briefly developing along it. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section above for more details on a developing gale warning in the Gulf of Papagayo. For the Gulf of Panama, moderate to fresh northerly winds will continue and extend southward along the Azuero Peninsula will increase to fresh to strong tonight as the local pressure gradient tightens. Fresh to strong winds will then persist through early Fri, even approaching 30 kt near the Azuero Peninsula Tue night and Wed night. Elsewhere, gentle to moderate offshore flow will prevail north of 09N, and light to gentle south-southwest winds will generally prevail south of 09N. REMAINDER OF THE AREA... Fresh to strong winds offshore of southern California mainly to the north of Point Conception follow a weakening cold front which extends from southern Nevada to across Baja California norte to 27N130W. These winds are generating fresh north- northeast swells. The swells will spread south through the next few days, with seas of 7-10 ft propagating to the south- southwest and eventually mixing with longer period northwest swell. A surface trough is analyzed from 17N121W to 10N124W. Associated scattered moderate convection covers an area bounded by 22N111W to 11N109W to 12N118W to 07N128W to 13N130W to 18N124W to 22N111W. Winds near the trough are currently moderate to fresh, however, trades to the west of the trough will increase by the end of the week, building fresh seas to around 8 ft as the pressure gradient tightens between building high pressure north of the area, and the troughing. $$ Lewitsky