000 AXPZ20 KNHC 230932 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Mar 23 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A ridge across the Gulf of Mexico is supporting minimal gale force winds in Tehuantepec, with seas to 12 ft. Winds will diminish below gale force this afternoon, and marine conditions will improve significantly on Saturday as the ridge shifts eastward and weakens. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N79W across Panama to 07N86W. The ITCZ axis continues from 07N86W to 02N97W to 06N122W to 06N140W. Scattered moderate convection is within 90 nm of the axis between 84W and 103W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on gale force winds expected to affect the Gulf of Tehuantepec. A weak cold front west of northern Baja is expected to dissipate today. High pressure building behind the remnant front through this weekend will support moderate to fresh NW winds west of the Baja peninsula. Winds will increase further Mon as the pressure gradient between the ridge and area of low pressure developing over northern Mexico tightens. Gulf of California: Light to gentle variable winds will dominate the gulf waters through the weekend. Winds will become moderate to fresh on Monday, and fresh to strong in the southern half of the area on Wednesday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Santa Maria Volcano in Guatemala at 14.75N 91.55W erupted on Thursday, and satellite imagery showed its ash cloud drifting SW becoming diffuse over the Pacific. Hazy conditions and reduced visibilities are possible during these eruptions, and conditions could deteriorate rapidly with little warning. Gulf of Papagayo: Fresh to strong northeast winds downstream from the Gulf of Papagayo, mainly during the night, are expected to persist through the middle of next week, with seas building to 10-11 ft each morning. Fresh to strong northerly winds are also expected downstream of the Gulf of Panama through this evening. Light to gentle winds will prevail elsewhere across the region through Sunday. REMAINDER OF THE AREA... A weak cold front extends from 30N121W to 25N131W. The front will dissipate by tonight. High pressure will build eastward behind what is left of the front tonight and Sat, with the ridge axis roughly along 29N. NW swell associated with the frontal system in NW forecast waters will gradually subside through Sat. An intense low pressure system is expected to develop north of the Hawaiian Islands Sat night then drift northward through Tue. Large swell associated with this system may affect the waters W of 135W Sun through Mon night. $$ Mundell