000 AXPZ20 KNHC 082130 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Mar 8 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ axis extends from 04N100W to 03N109W to 05N118W to 03N128W to 04N140W. Scattered moderate convection is within 45 nm either side of the ITCZ axis west of 134W. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC... High pressure in the Gulf of Mexico is expected to induce strong north to northeast gap winds funneling through the Chivela Pass into the Gulf of Tehuantepec. Previously, model guidance showed a moderate likelihood of gale force winds late tonight into Thursday morning, but the trend in GFS model winds during the past several model runs has been weaker, and the latest 12Z model only shows peak winds of 33 to 34 kt at 03Z and below gale force at other times tonight. So have pulled the plug on a gale warning, and now expect near-gale 30 kt winds overnight. The high is weaker and further north, which will limit the potential for gap winds to reach gale force. Nocturnal winds will remain fresh to strong through Saturday morning, then the high will shift east into the Atlantic and the pressure gradient relaxes. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure centered north of the area near 33N130W ridges southeastward to near the Revillagigedo Islands. The pressure gradient between the high and a trough over western Mexico supports moderate to fresh N to NW winds, with 4-5 ft seas in the central and southern Gulf of California and 5-6 ft seas off the western coast of Baja. Winds and seas will diminish tonight as the low weakens. The high will remain nearly stationary north of the discussion area through the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong trade winds in the western Caribbean Sea are funneling through gaps in Central America such as the Gulf of Papagayo. Strong winds will continue to pulse primarily during late night and early morning hours in the Gulf of Papagayo through Saturday morning. Seas will peak around 9-10 ft each morning. High pressure in the Caribbean is expected to remain weak during the first half of next week, maintaining a calmer weather pattern. Fresh to locally strong winds will pulse over the Gulf of Panama tonight through Thursday morning. REMAINDER OF THE AREA... Subtropical high pressure centered near 33N130W extends a broad ridge southward west of Baja California to 15N. Model guidance is in good agreement keeping the high nearly stationary through the weekend, with ridging staying well established over forecast waters north of the ITCZ. An area of fresh trade winds and 8-10 ft seas in mixed swell currently from 04N to 21N west of 120W will slowly shrink in size and shift westward through Monday. Reinforcing NW swell will reach the northwest corner of the discussion area on Thursday due to a stationary front, but it will quickly decay as the front weakens and lifts north of the area. Seas to 7-8 ft associated with this swell will be mainly north of 25N and west of 135W. $$ Mundell