000 AXPZ20 KNHC 051524 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1524 UTC Thu Jan 5 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 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from low pressure near 09N74W to 05N96W to 07N105W. The intertropical convergence zone axis extends from 07N105W to 08N120W to 09N134W. Scattered moderate convection is within 210 nm west of the coast of Colombia south of 07N, from 04N to 05.5N between 88W and 93W, and also from 08N to 09.5N between 113W and 116W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak 1019 mb high pressure persists west of the Baja California peninsula near 26N122W, and is helping to produce gentle to moderate northwest winds across the Pacific waters off the coast of Baja California, with seas in the 3 to 5 ft range. The pressure gradient will tighten slightly offshore of Baja California Sur tonight into early Friday, allowing for northwest flow to increase to moderate to fresh, then will diminish this weekend as the gradient relaxes to the west of the peninsula. In the Gulf of California, moderate northwest flow across the southern half will diminish to gentle through the day, then will increase to fresh to strong early this weekend as the pressure gradient tightens. The stronger winds will persist through the end of the weekend, but will diminish early next week as the gradient slackens. Seas will build to 5 to 8 ft this weekend. In the Gulf of Tehuantepec, winds have diminished this morning and will back to the southwest to south through the day. Seas of 4 to 6 ft will also subside to 2 to 4 ft by late in the afternoon. A strong cold front will move through the Gulf of Mexico to the north of the area Friday through Saturday. Winds will rapidly become northerly while increasing to 20 to 30 kt in the Gulf of Tehuantepec by early Saturday morning, then increasing to gale force by Saturday afternoon. Model guidance continues to indicate winds increasing to storm force by late Saturday night, continuing into early Monday. Wave model guidance indicates a very large area of high seas well away from the source region, with significant wave heights in the Tehuantepec area building to 23 to 25 ft by Sunday night. Elsewhere between Cabo Corrientes and the Tehuantepec region, light to gentle breezes and seas in the 3 to 5 ft range, primarily in northwest swell, will prevail over the next several days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, fresh to locally strong winds will diminish by the afternoon, then will pulse to moderate to fresh at night into early Saturday. Offshore flow will then increase back to fresh to strong Saturday night, with winds approaching near gale force by late Sunday into Monday as strong high pressure ridges southward across interior Central America in the wake of the Gulf of Mexico/Caribbean cold front. In the Gulf of Panama, nocturnal northerly flow will continue to pulse to fresh during the next few nights, increasing to fresh to strong early next week due to the strong high pressure ridging. These gap winds, along with a possible storm force event in the Gulf of Tehuantepec, will generate a very large area of high seas that will eventually extend from Tehuantepec to Papagayo to just northwest of the Galapagos Islands, spreading westward to 110W by early Tuesday. Elsewhere, light to moderate south to southwest winds will prevail south of the monsoon trough region, with seas 5 ft or less through the end of the week and the upcoming weekend. REMAINDER OF THE AREA... A weak to modest pressure gradient prevails elsewhere over the forecast waters. Moderate to locally fresh trade winds prevail south of the high between 115W and 140W, between the ITCZ and about 17N. Combined seas are generally running between 6 to 9 FT across this zone. Across the far northwest waters, a weak cold front extends from 30N136W to 27N140W. An associated area of 8 to 11 FT seas in mixed northerly swell is present across the northwest waters. The cold front will stall by late tonight, then will get reinvigorated and shift slightly east during the day Friday, before stalling again by early Saturday. Southwest winds just ahead of the boundary will increase to at least fresh to strong during the day Friday, helping to support combined seas of 7 to 9 ft. The boundary will shift eastward through the weekend, gradually weakening through early next week with tranquil conditions expected by then. $$ LEWITSKY