000 AXPZ20 KNHC 010311 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Apr 1 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: The pressure gradient between high pressure ridging along the Sierra Madre Oriental and lower pressure associated with the equatorial trough is supporting minimal gale force winds over the Gulf of Tehuantepec, where seas are reaching near 12 ft. The minimal gale conditions are expected to continue through late tonight. The high pressure located north of the area will shift eastward over the next 24 hours. This will loosen the pressure gradient and help diminish winds below gale force by this morning. In response to the shifting of high pressure, winds over the SW Gulf will veer. This will further diminish winds funneling through the Chivela pass into the Gulf of Tehuantepec and bring an end to this latest gap wind event, with winds diminishing below 20 kt by Sun evening. Please refer to the High Seas Forecast issued by the National Weather Service under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. This information also is found at the following website: www.hurricanes.gov/marine. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... During March and April of each year, a doble ITCZ is usually present in the Southern Hemisphere on the eastern Pacific basin. Based on this pattern no monsoon trough is currently present E of 140W. Only a surface trough is analyzed from 08N79W to 04N90W to 08N105W. The ITCZ axis continues from 08N105W to 09N115W to 07N130W to 08N140W. Scattered moderate convection is noted from 02N to 05N between 81W and 88W, and from 09N to 13N between 108W and 115W. A second ITCZ axis is seen S of the Equator and extends from 02S01W to 04S100W to the Equator at 111W. Scattered moderate convection is from 04S to 07S between 98W and 103W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for more information on the latest Gulf of Tehuantepec gale force gap wind event. Elsewhere, a weak pressure pattern will prevail over the forecast area this Sunday. This will maintain mainly light and gentle winds over the open waters off the SW coast of Mexico as well as W of the Baja California Peninsula. Seas of 3 to 6 ft will prevail over these waters. High pressure will start to build closer to the forecast area early next week. This will bring a slight increase to winds, with gentle to moderate NW to N winds developing across the offshore waters W of Baja California. In response to the increase in winds, seas will build to 4 to 7 ft over this area through the middle of the next week. Gulf of California: Mainly light to gentle winds will prevail over much of the gulf the next several days. Winds will increase to gentle to moderate over the northern gulf tonight through Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Winds will pulse to fresh to locally strong through Sun morning, with seas building to near 8 ft downstream of the gulf. Gulf of Panama: Winds will pulse to fresh to locally strong across the western part of the gulf, and near the Azuero peninsula through Sun morning. Elsewhere, gentle to moderate offshore flow is generally expected N of 09N through Tue, while light and variable winds are forecast S of 09N. REMAINDER OF THE AREA... A 1026 mb high pressure located near 40N134W extends a ridge SE across the forecast waters to near the Revillagigedo Islands while a 1018 mb low pressure is over the far NW corner of the forecast area. Under this weather pattern, mainly gentle to moderate winds prevail, reaching near 20 kt just N of the ITCZ and west of 130W, with seas to 7 ft based on altimeter data. The weak pressure pattern will prevail through the middle of next week, resulting in winds of 20 kt or less, and seas less than 8 ft. $$ GR