000 AXPZ20 KNHC 080330 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Mar 8 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Building high pressure behind a cold front moving across the SW Gulf of Mexico will induce a brief gap wind event across the Gulf of Tehuantepec. Winds are forecast to increase to minimal gale force this evening, with seas building to 9-11 ft. Winds will further increase to 30-40 kt by early Thu morning, with seas in the 11-13 ft range. Winds will diminish below gale force Thu afternoon. Marine guidance suggests another gap wind event across the Tehuantepec region late Sun night through Mon night. Please, refer to the latest High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 06N85W to 05N93W. The ITCZ axis extends from 05N93W to 03N102W to 03N126W to 07N140W. Scattered moderate convection is from 08N to 12N between 129W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Long period NW swell continues to propagate southward west of the Baja California peninsula. Seas are subsiding to 4-5 ft in offshore waters. Weak high pressure of 1018 mb located near 30N122W will produce gentle to moderate moderate NW-N winds across the offshore waters of Baja California through at least Fri. Winds are forecast to increase to 15-20 kt Sun through Mon as the high pressure located just west of offshore waters strengthens some. Gulf of California: Light to gentle winds are expected across the northern Gulf through Sat, with mainly gentle to moderate winds across the central and south waters. Winds are expected to increase to 10-15 kt across the northern Gulf on Sun through Mon, becoming 15-20 kt across the central and south waters. Gulf of Tehuantepec: Please, see SPECIAL FEATURES section for details. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fuego Volcano located near 14.5N 90.9W in Guatemala continues to vent intermittent volcanic ash and smoke based on reports from the Weather Service in Guatemala (INSIVUMEH). Computer model guidance suggests that the volcanic ash will drift NW over land. Moderate NE winds in the SW Caribbean passing through Central America are producing fresh to strong offshore gap winds in the Gulf of Papagayo and Gulf of Panama. Across the Papagayo region, fresh to strong winds will continue through Fri and are expected to pulse to 30 kt tonight through early Sat morning, with seas building to 10 ft. 25 kt winds are likely during late night and early morning hours through the weekend, with max seas around 8 ft. In the Gulf of Panama, fresh northerly winds will pulse to strong during the overnight and early morning hours through Thu night. Seas are expected to be 6 to 8 ft as northerly wind waves mix with moderate cross-equatorial SW swell. Elsewhere, expect gentle to moderate winds and 4-7 ft seas through the next couple of days. REMAINDER OF THE AREA... A weakening cold front extends from 30N128W to 21N137W. Long period NW swell follows the front, with 8-11 ft seas in NW waters. The front will move E and dissipate to a frontal trough. The swell is mixing with easterly wind waves to produce an area of 8-11 ft seas N of 10N W of 128W. This swell will gradually fade over the next 24 to 48 hours, and significantly reduce the area of 8 ft or higher seas. By Fri, seas of 8-9 ft will roughly cover the waters from 05N to 18N W of 118W. $$ Mundell