000 AXPZ20 KNHC 102118 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1901 UTC Sat Mar 10 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 1800 UTC surface analysis and satellite imagery through 2015 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ axis extends from 04N94W to 04N106W to 02N119W to 07N136W to beyond 07N140W. Scattered moderate and isolated strong convection is noted from 06N to 08N W of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weakening 1020 mb high pressure centered near 29N119W ridges SE across the open waters W of the Baja California peninsula. Mainly light to moderate NW to N winds prevail beneath this ridge. These conditions will continue tonight. 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 Wed night and 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. Gulf of Tehuantepec: Light to moderate onshore winds will prevail through Sun night. Model guidance suggests another northerly gap wind event commencing Mon as expansive high pressure builds southward over the western Gulf of Mexico behind the next cold front. Winds will rapidly increase to gale force Mon afternoon, peaking around 40 kt overnight into early Tue. Gale force winds may 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 Tue morning. 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 continues to intermittently vent light amounts of smoke and ash. Any significant ash emissions that do occur will likely remain over land to the SW of the summit during the next 12 to 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 mid week. Over the Gulf of Panama, gentle to moderate winds will prevail through Wed. 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 4-7 ft seas to prevail during the next couple of days. REMAINDER OF THE AREA... Surface troughing extending SW from 29N132W to 24N135W to beyond 19N140W and a cold front curving W from 30N126W to 29N128W to 30N131W are associated with broad deep layer low pressure situated over the NW and N central waters. A plume of deep tropical moisture extends from SE of the Hawaiian Islands northeastward over the discussion waters. Scattered moderate convection is present within 60 nm of the front as well as within 90 nm of a line from 26N131W to 20N140W. Conditions in the vicinity of the cold front will lift N of the area this evening. The next cold front will breach 30N140W from the NW by Sun afternoon. 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 N of the intertropical convergence zone to 15N. The pressure gradient will weaken on Sun and allow seas to subside to less than 8 ft in this area by Mon. $$ CAM