000 AXPZ20 KNHC 040919 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Mar 4 2019 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 0830 UTC. ...SPECIAL FEATURES... Open East Pacific Waters Gale Warning: A pre-frontal trough has crossed SE of 30N140W with a trailing cold front W of 140W approaching the area. Fresh to strong winds are N of 27N ahead of the front, along with seas to 8 ft. The cold front will cross into the area later today ushering in fresh to near gale force winds N of 27N, with frequent gusts to gale force likely. A set of large NW swell of 16 ft will also accompany the front. Winds will diminish below gale force by Tue afternoon, then to fresh levels Tue night, while the swell train continues off to the SE, gradually subsiding to less than 8 ft through Thu. Gulf of Tehuantepec Gale Warning: A strong cold front moving across the Gulf of Mexico will force the next gap wind event across the Tehuantepec region beginning early Tue. Northerly winds of fresh to strong will arrive Tue morning, increasing to gale force by Tue afternoon, peaking at 40 kt Tue night. Gale force winds will then continue into early Thu, with fresh to near gale thereafter through early Fri before diminishing further. Seas will peak around 16 ft during the strongest winds. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details about these gale warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from near the Colombia/Panama border at 07N78W to 07N88W. The Intertropical Convergence Zone axis continues from 07N88W to 01N110W to 03N125W to 04N140W. Scattered moderate convection is from 07N to 09N between 83W and 86W, from 01N to 05N between 95W and 102W, and also from 03N to 06N between 128W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please read the Special Features section for more details about the Gale Warning. A ridge will dominate the offshore waters W of Baja California through Wed. The pressure gradient has tightened between the ridge W of Baja California and lower pressures over mainland Mexico, resulting in fresh to strong winds offshore of Baja California Sur. These winds will diminish by this evening. On Thu, a weakening cold front will reach Baja California Norte with minimal impacts. No large long-period swell is anticipated to affect the region. Gulf of California: Generally benign marine conditions are expected through early this week with mainly gentle to moderate winds. Wed night through Fri night, a weakening front and pre- frontal trough will reach the Gulf region with fresh to strong SW flow N of 30N pulsing each night Wed night through Fri night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Fonseca: Fairly tranquil marine conditions will persist through early Tue night. Winds will increase to fresh to strong late Tue night through early Fri as the pressure gradient across the region tightens. Gulf of Papagayo: Fresh to strong winds are expected through Tue, but mainly at night with the assistance of the drainage flow. An increase in the Caribbean pressure gradient will significantly boost winds Tue night through Fri night, when strong to near gale force winds are expected. Seas are forecast to peak around 10 to 12 ft during the strongest winds. Gulf of Panama: Moderate to fresh winds will prevail through Tue. A tightening pressure gradient from high pressure building to the north will bring fresh to strong N winds Tue night through at Fri night. Seas will build to around 9 ft Thu morning, then to around 10 ft Fri morning. Elsewhere, benign marine conditions can be expected through at least Fri night. No large long-period swell events are anticipated to impact the waters for the next several days, however, fresh NE swells generated by the Gulf of Panama winds will spread SW towards the Galapagos Islands by the end of the week. REMAINDER OF THE AREA... Marine conditions are beginning to deteriorate N of 25N W of 125W as low pressure and associated boundaries affect this region. Please see the Special Features Section for more details on a developing gale warning. Elsewhere, long-period NW swell mixing with tradewind flow is maintaining an area of 7 to 9 ft seas from 06N to 13N W of 126W. These seas will gradually subside to less than 8 ft by early Tue. Later in the week, another combination of mixed NW swell and wind waves are expected to support seas of 7 to 9 ft roughly across the same area. $$ Lewitsky