000 AXPZ20 KNHC 110242 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 242 UTC Sun Mar 11 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 0215 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Light to moderate onshore winds will prevail through early Mon morning. Strong high pressure ridging will build southward along eastern Mexico and the western Gulf of Mexico behind a strong cold front through the early part of the week. Winds will become northerly and rapidly increase to fresh to strong in the Gulf of Tehuantepec by late Mon morning, continuing to increase to gale force around sunset Mon evening, and peaking around 40 kt Mon night into early Tue. Gale force winds will likely diminish by midday Thu, with brief lulls below gale force also possible during the afternoon hours Tue and Wed. Seas will peak around 16 ft Mon night into Tue morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 06N83W to 04N95W. The ITCZ axis continues from 04N95W to 02N116W to 05N130W to 07N140W. Scattered moderate and isolated strong convection is noted from 08N135W to 06N136W to 06N137W to 06N140W to 10N140W to 08N135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information on the Gulf of Tehuantepec developing gale warning. Weakening 1020 mb high pressure centered near 30N118W ridges SE across the open waters W of the Baja California peninsula. Mainly light to moderate NW to N winds prevail beneath this ridge. Winds will increase to between 15 and 20 kt Sun through Tue as the high gradually builds. The high will then dissipate by mid-week as a decaying cold front approaches. Winds near Cabo Corrientes could become locally strong tonight through Sun. Long period NW swell will cause seas to build to between 6 and 8 ft W of 110W Wed through Thu. Gulf of California: Light to gentle winds are expected across the basin tonight. Winds will increase to between 10 and 15 kt across the Gulf S of 28N Sun through Tue in response to building high pres just NW of the offshore zones. Winds will become fresh to locally strong over the waters S of 26N Sun night. The pressure gradient across the region will weaken Tue night through Thu, which will allow winds to diminish to between gentle and moderate across the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The Fuego Volcano located in Guatemala near 14.5N90.9W is not currently emitting volcanic ash, with none forecast for the next 24 hours. High pressure ridging over the Caribbean from the SW Atlc will be just strong enough to support one more round of fresh to strong winds over the Gulf of Papagayo, tonight through Sun morning. The fetch length of the winds will not be long enough to generate 8 ft seas. The ridging will continue to weaken but still produce pulsing moderate to fresh winds Sun night through Wed, then increasing back to fresh to strong Wed night and again Thu night as the gradient restrengthens. Over the Gulf of Panama, gentle to moderate winds will prevail through Wed, increasing to moderate to fresh thereafter. Seas are expected to be 4 to 6 ft as moderate cross-equatorial SW swell continue to arrive. Elsewhere, expect gentle to moderate winds and 4 to 7 ft seas to prevail. REMAINDER OF THE AREA... A complex pattern remains across the NW portion and N central waters with one cold front extending from 1011 mb low pressure N of the area near 33.5N122W through 30N125W to 28N130W, with a second cold front extending from 1011 mb low pressure near 31N133W to 23N135W to 18N140W. A plume of deep tropical moisture extends from SE of the Hawaiian Islands northeastward over the discussion waters. Scattered moderate convection is present within an area bounded by 29N115W to 19N140W to 22N139W to 27N133W to 30N122W to 29N115W, including across the Sebastian Vizcaino Bay and the northern Gulf of California. Associated winds with these features are mainly light to locally moderate, with seas in the 4 to 6 ft range. A stronger cold front will approach 30N140W from the NW by early Sun morning. An area of fresh to strong winds will precede the front, as well as follow it, finally diminishing by Mon night. Large NW swell will also accompany the boundary, reaching as high as 14 to 16 ft by Mon evening. The front will weaken as it moves across the waters N of 24N and W of 125W. A weaker cold front will introduce a round of reinforcing NW swell Wed night and Thu. Moderate to locally fresh trades combined with decaying NW swell are supporting combined seas of 7 to 9 ft across the waters from 06N to 11N between 129W and 136W. The pressure gradient will weaken on Sun and allow seas to subside to less than 8 ft in this area by Sun afternoon. $$ Lewitsky