000 AXPZ20 KNHC 230324 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0300 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 Fri afternoon, and marine conditions will improve significantly on Saturday as the ridge shifts eastward and weakens. Ashfall Advisory: Santa Maria Volcano in Guatemala at 14.75N 91.55W is erupting, and satellite imagery shows its ash cloud drifting SW, becoming diffuse over the Pacific. Hazy conditions and reduced visibilities are expected during eruptions, and conditions could deteriorate rapidly without notice. Mariners operating in the vicinity of Santa Maria are urged to exercise caution. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N79W across Panama to 06N88W. The ITCZ axis continues from 06N88W to 04N92W to 07N128W to 07N140W. Scattered moderate isolated strong convection is from 03N to 06N between 87W and 111W. ...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 weakening cold front approaching the northern Baja peninsula is expected to dissipate before reaching land. High pressure building behind the front this weekend will support moderate to fresh NW winds west of the Baja peninsula. Winds will increase further on Monday as the pressure gradient between the ridge and area of low pressure developing north of Texas 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... Please see the Special Features section above for details on an Ashfall Advisory affecting the coastal waters of Guatemala. 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 Friday evening. Light to gentle flow will prevail elsewhere across the region. REMAINDER OF THE AREA... A dissipating cold front extends from 30N119W to 19N130W. The front will weaken then dissipate by Fri night. High pressure will build eastward behind the front Fri night and Sat, with the ridge axis along 29N. Large 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 will affect the waters W of 135W Sun through Mon night. $$ Mundell