000 AXPZ20 KNHC 131555 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1539 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A stationary front extends 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 through the remainder of the early morning hours, and again through early Wed. The gale force winds will likely diminish early Thu, with fresh to near gale winds pulsing thereafter. Gulf of Papagayo Gale Warning: Fresh to near gale force offshore winds have expanded in coverage overnight, 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 this evening through at least Wed, with fresh to near gale force thereafter into the upcoming weekend. Downstream seas will build to 8-11 ft late this evening 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 Costa Rica near 10N83W to 03N90W to 03N97W. The ITCZ axis continues from 03N97W to 10N125W to 08N135W to 09N140W. Scattered moderate convection is from 06N to 10N between 112W and 118W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on a gale warning in the Gulf of Tehuantepec. A weakening cold front extends from southern Nevada to across Baja California norte and offshore to near 27N120W, with fresh to strong southerly winds in the northern Gulf of California ahead of it. Seas are likely close to 8 ft despite the relatively limited fetch area. Winds will diminish this morning 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, fresh to strong northerly winds will continue to extend southward along the Azuero Peninsula with a locally tight pressure gradient. These winds will persist through early Fri, even approaching 30 kt near the Azuero Peninsula late tonight and again overnight 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 26N129W. 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 17N124W to 11N127W. Associated scattered moderate convection is from 12N to 17N between 117W and 126W. 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. $$ Formosa