000 AXPZ20 KNHC 182122 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2036 UTC Mon Nov 18 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N83W to the remnants of T.D. Twenty-one E near 12N106W to a second low near 14N111W to 12N115W. The intertropical convergence zone reaches from 12N115W to 09N140W. Scattered moderate convection is active within from 07N to 09N between 85W and 95W and from 07N to 09N between 95W and 100W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: The pressure gradient between high pressure over the western Gulf of Mexico and the monsoon trough in the eastern north Pacific is supporting strong to near gale force gap winds in the Gulf of Tehuantepec, with resulting seas near 11 ft. Fresh to strong northerly winds will continue to blow across the Tehuantepec region through Tue night. Winds and seas will diminish on Wed as the area of high pressure shifts eastward and the pressure gradient loosens. Fresh to strong winds, and seas in the 8-11 ft range are in portions of the Sinaloa and Baja California Sur offshore waters, associated with the remnant surface low pressure of Raymond. Winds and seas will diminish over this region by late tonight. An upper- level low spinning near 26N120W supports scattered showers and isolated thunderstorms over parts of the offshore waters of Baja California, including also parts of Baja California and the Gulf of California. Moisture and the likelihood of showers will persist across this area through at least Tue. Winds and seas will increase off Baja California Norte and over the northern Gulf of California late Tue night as a cold front moves across the region. Seas will build to 8-11 ft by Thu over the waters north of Punta Eugenia. Fresh to strong SW winds will persist in the northern Gulf of California through Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong winds will pulse across the Gulf of Papagayo each night through Wed night, with seas briefly building to 8 ft. Elsewhere, gentle to moderate southwest monsoonal flow will continue across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador for the next several days. Wave heights will generally remain in the 4-7 ft range. REMAINDER OF THE AREA... The remnants of the recently downgraded Tropical Depression Twenty- One is centered near 12.4N 106.1W at 18/2100 UTC drifting west at 5 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 20 kt with gusts to 30 kt. Very little convection is observed with this low pressure area, and an earlier scatterometer satellite image indicated modest wind flow barely reaching 20 kt. The low pressure is expected to become elongated along the monsoon trough tonight and dissipate as a coherent low pressure system Tue. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Elsewhere a weak surface ridge extends from high pressure centered near 32N140W to near 18N120W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh winds N of the ITCZ and W of 130W. Additional pulses of long period NW swell will continue to impact the waters today and Tue with seas of 8 to 9 ft north of 15N and west of 135W. Another set of large, long period NW swell is forecast to reach the forecast waters north of 20N west of 130W Thu night, with seas peaking near 13-14 ft Fri. $$ Christensen