000 AXPZ20 KNHC 070315 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 042 UTC Fri Dec 7 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. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pres 1009 mb near 06N75W to 09N86W to 07N90W to 06N95W. The ITCZ continues from 06N95W to 10N119W. The ITCZ resumes from 10N123W to 10N127W to 08N132W to beyond 08N140W. Scattered moderate and isolated strong convection is observed from 05N to 07N between 89W and 92W and within 90 nm of the ITCZ axis between 126W and 135W. An area of convergent trade winds is generating scattered moderate and isolated strong convection within 90 nm of a line from 25.5N109W to 22.5N111W. A cold front stretching from 29N114.5W to 27N116W to 21N122W. Scattered moderate and isolated strong convection is found within 60 nm of a line from 25.5N109W to 22.5N111W. ..DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: High pressure ridging SW across the Gulf of Mexico from the SE United States will maintain strong N winds over the Gulf of Tehuantepec through Fri night, then the high will have moved over the NE United States. This will allow the ridge over the western Gulf to break down and winds to subside. The next gap event will quickly ramp up Sun afternoon as strong high pres builds S along the eastern slopes of the Sierra Madre Oriental behind s cold front. Strong gale conditions are expected to develop Sun evening, then persist through Wed afternoon. The area of 8 ft seas generated by this event will spread SW then W to as far S as 03N and as far W as 110W by Tue evening. Gulf of California: A cold front is entering the far NW gulf. The front will quickly sweep SE through the northern gulf waters tonight, then over the southern gulf waters by Fri afternoon. Fresh N flow that will spread SE across the north and central Gulf waters Fri evening through Sun evening. Winds are then expected to diminish Mon. Elsewhere: A cold front is pushing SE across the Baja Peninsula from 32N115W to 29N115W to 27N116W to 21N122W. A surface trough following the front by about 150 nm will dissipate by Fri afternoon. The front will quickly move SE across the region, and reach from Baja California Sur over the southern Gulf and through Cabo San Lucas by Fri evening, and then dissipate near Las Tres Marias by Sat morning. Long-period NW swell following in the wake of the front will cause seas to build to between 6 and 9 ft overnight, and between 7 and 10 ft across the northern and central waters on Fri as the swell reaches Baja California Sur. High pres will then build across the Baja offshore waters Fri night and Sat behind the front to produce moderate N wind flow as seas peak between 8 and 10 ft for all of the Baja waters. Seas will then begin to subside from the N, subsiding between 5 and 7 ft by Sun evening. The next round of long-period NW swell, in the form of 7 to 9 ft seas, will reach 32N120W on Mon, then propagate S across the waters W of the entire Baja Peninsula on Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The intermittent volcanic ash plume trailing WSW from the Fuego Volcano over interior Guatemala has tapered off significantly during the past 6 hours. Little, if any ash is reaching the coast of Guatemala at present. Gulf of Papagayo...Nocturnal pulses of fresh to locally strong NE winds, and 6 to 8 ft seas, will linger through Fri evening, then winds and seas will subside. Strong winds will begin pulsing over the Gulf of Papagayo again Sun night. Elsewhere: The monsoon trough will meander between 08N and 10N with light to gentle variable flow, and 3 to 6 ft seas, forecast N of the monsoon trough, and moderate SW monsoonal flow, and 3 to 6 ft seas, forecast S of the monsoon trough. REMAINDER OF THE AREA... Long period NW swell, manifesting in the form of a large area of 8 to 13 ft seas, is forecast to continue propagating SE to encompass almost all of the forecast waters W of 110W by Sat afternoon. This area of swell will decay by Mon. Trade-wind waves and swell will support a large area of 8 to 10 ft seas S of 17N and W of 105W by Sun night. Another cold front will reach 32N137W on Fri, accompanied by a moderate wind shift. A stronger cold front will reach 32N140W on Sat evening accompanied by a fresh wind shift and large post- frontal NW swell. Robust high pres building to the N of the ITCZ will support strong winds and 10 to 12 ft seas from 11N to 20N and W of 135W by Tue afternoon. $$ CAM