000 AXPZ20 KNHC 050946 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from 08.5N72W TO 09N85W TO 04.5N95W TO 06.5N106W. The ITCZ extends from 06.5N106W to low pres near 08N135W TO beyond 06.5N140W. Clusters of scattered strong convection is noted from 01N to 07N east of 81W to coastal Colombia. Widely scattered moderate to strong convection is noted within 60 nm of the trough between 85W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak 1020 mb high pressure persists west of Baja California Norte tonight, centered near 28N121W, and is helping to produce gentle to moderate northerly winds across the Pacific waters off the coast of Baja California tonight. Seas in the 3 of 5 ft range prevail over this area. The pressure gradient will tighten slightly offshore of Baja California Sur through the end of the week, allowing for northwest flow to increase to moderate to fresh, then diminishing this weekend as the gradient relaxes to the west of the peninsula. In the Gulf of California, a locally tight pressure gradient is supporting fresh northwest winds of around 20 kt flow S of 27N late tonight, where seas are 4 to 6 ft. The gradient will begin to relax in the gulf by early morning, then will tighten more significantly this weekend with northwest flow increasing to fresh to strong south of 27N, which will build seas to 5 to 8 FT. In the Gulf of Tehuantepec, fresh to strong northerly winds will continue overnight into the early morning hours before diminishing. Light southerly flow will then prevail later today through Friday evening with seas of 2 to 4 ft. A strong cold front will move through the Gulf of Mexico to the north of the area Friday through Saturday. Winds will become northerly and rapidly increase to 20 to 30 kt in the Gulf of Tehuantepec by Saturday morning, then increasing to gale force by Saturday afternoon. Model guidance continues to indicate winds increasing to storm force by early Sunday morning, continuing into Monday. The potential exists for this weekend event to become the strongest gap wind event thus far this cold season. 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 continue overnight into the early morning hours, then become moderate to fresh thereafter through 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. 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 26.5N140W. An area of 8 to 11 FT seas in mixed southeast and northwest swell is present across this area NW of a line from 30N135W TO 23N140W. The cold front will gradually dissipate with a remnant boundary found from 30N135W to 26N140W by 24 to 36 hours. Deepening low pressure NW of the area and across the NE Pacific will generate additional NW swell that will continue to propagate to the south and southeast, gradually mixing with the fresh trade wind seas to the south through the end of the week. The next frontal system and associated increasing winds and seas may approach the far northwest portion of the discussion area by late Saturday. $$ Stripling