000 AXPZ20 KNHC 022130 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2130 UTC Mon Dec 2 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. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Earlier scatterometer data from 1530-1600 UTC confirmed near gale to minimal gale force gap winds over the Gulf of Tehuantepec. A recent altimeter pass sampled seas to 12 ft downstream of the Gulf. High pressure over eastern Mexico will maintain a north-south pressure gradient across the region through tonight. This will support minimal gales through early Tue morning, with seas expected to peak around 15 ft late tonight. High pressure will weaken on Tue, which will allow the gradient to relax and wind speeds to diminish below gale force Tue morning. See latest NWS High Seas Forecast issued by National Hurricane Center under AWIPS/WMO headers HSFEP2/FZPN03 KNHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...TROPICAL WAVES... A tropical wave axis is near 118W south of 16N, moving westward around 10 kt. Scattered moderate isolated strong convection is noted from 10N to 14N between 114W and 122W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N76W to 1011 mb low pressure near 07N103W to 09N110W to 1012 mb low pressure near 10N128W to 09N140W. Scattered moderate convection is noted within 120 nm of the monsoon trough between 102W and 107W, and within 120 nm of the monsoon trough west of 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information about the ongoing gale force gap wind event in the Gulf of Tehuantepec. Looking ahead, another gale force gap wind event is possible Fri night into Sat. Fresh NW to N winds are noted in earlier scatterometer data over the southern Gulf of California southward across the entrance to the Gulf. Elsewhere, gentle to moderate northerly flow prevails over the Baja California Sur offshore waters southward to Cabo Corrientes. Light and variable winds continue off the coast of southern Mexico as well as offshore of Baja California Norte. Large NW swell is currently propagating across the Baja offshore waters, with 8-11 ft seas over the waters north of Punta Eugenia. Large NW swell will continue propagating SE into the Baja California Sur waters through Tue night, then decay on Wed as combined seas subside below 8 ft. A weak high pressure ridge will move eastward across the northern waters Tue and Tue night, briefly tightening the offshore gradient and producing fresh northerly winds near Punta Eugenia. A weakening cold front or trough will pass over the northern waters Wed and Wed night. Fresh northerly flow will resume over the central and southern Gulf of California Thu night through Fri. The next set of large NW swell will move into the waters off Baja California late Fri night through Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds will pulse across and downstream from the Gulf of Papagayo through Sat. Moderate to locally fresh northerly winds will pulse across the Gulf of Panama through mid week, then diminish on Thu. Elsewhere, gentle to moderate S to SW monsoon flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador during the next several days, along with weak S to SW swell. REMAINDER OF THE AREA... Large NW swell dominates the NW portion of the forecast waters. Recent altimeter data showed 8-14 ft seas across the northern waters north of 20N west of 125W. The associated swell will continue moving SE across the high seas while slowly subsiding through Wed night. A surface trough will develop west of Baja California on Tue ahead of an approaching cold front. The enhanced pressure gradient between this trough and a ridge over the offshore waters will support fresh to strong winds roughly north of 22N between 119W and 126W. This trough will drift northward through early Wed before weakening, followed by a cold front crossing the northern waters Wed and Wed night. Another large set of NW swell will move into the NW waters late Thu and propagate SE through Sat. $$ Reinhart