000 AXPZ20 KNHC 150321 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0315 UTC Sun Jan 15 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A tight pressure gradient generated by a surface high that extends across the Gulf of Mexico and lower pressures to its south will support gale-force winds across the Gulf of Tehuantepec tonight. These conditions will diminish within the next 24 hours as the surface high weakens and the pressure gradient relaxes. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... Surface trough from 04N78W to 1009 mb surface low near 01N82W to 02N85W. ITCZ extends from 04N93W to 03N104W to 09N121W. Another surface trough extends from 12N123W to 06N123W. ITCZ resumes near 08N124W to beyond 05N140W. Scattered moderate convection is from 06N-12N between 112W-122W and isolated showers from 08N-11N between 124W-131W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on the Gulf of Tehuantepec Gale Warning. A cold front extends from 27N110W to 22N113W to 19N120W. This front will continue to move southeastward through Baja California Sur and the Gulf of California. Seas to 8 ft will prevail behind the front off Baja California Norte. The front will gradually stall and dissipate from Cabo Corrientes to Socorro Island by early Monday. Winds will diminish within the next 24 hours. Meanwhile, 8 to 9 ft northwest swell will continue to propagate through the area about 120 nm off Baja California Norte through Tuesday, then diminish below 8 ft through mid week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo and along the south coast of Nicaragua, fresh to strong northeast flow will continue to pulse through early next week. Seas will build to 9 ft during the strongest winds. In the Gulf of Panama, moderate to fresh northerly winds will pulse to strong tonight before diminishing to fresh again by Sunday afternoon. Seas will be in the range of 5-7 ft, and subside to 4-5 ft on Monday. REMAINDER OF THE AREA... A strong high pressure is building south-southeast in the wake of the cold front described above. The combination of this high pressure and lower pressures to its south will lead to an increase of trade winds in the deep tropics mainly west 115W from tonight through early next week. Seas are currently ranging between 8-10 ft in this area, and will build to 10 to 12 ft by late Sunday through early Monday from 12N-16N between 125W-135W as the trades combine with a northwest swell. Converging trade winds in the lower levels along with jet dynamics aloft at the base of an upper-level trough are enhancing scattered showers and a few thunderstorms along the ITCZ and surface trough between 112W and 131W. Looking ahead, global models suggest that a large and deep low pressure system will move well to the north of the discussion area by the mid-week. A northwest swell generated by this system is expected to arrive in the far northwest portion of the area by early Wednesday, with strong southwest winds prevailing in advance of a cold front that may brush the far northern waters that evening. $$ NATIONAL HURRICANE CENTER