000 AXPZ20 KNHC 012112 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2110 UTC Sun Dec 1 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: Surface high pressure will build over the western Gulf of Mexico tonight in the wake of a cold front. The pressure gradient between this high pressure ridge and the monsoon trough over the eastern North Pacific will support minimal gale force gap winds across the Gulf of Tehuantepec late tonight through early Tue. Seas will build to 13 ft near and downstream of the Gulf Mon morning, and peak around 14 ft late Mon night. High pressure will weaken over the central Gulf of Mexico Tue into Tue night, allowing the gradient to relax and wind speeds to diminish. 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 117W south of 15N, moving westward around 15 kt. Scattered moderate isolated strong convection is noted from 09N to 15N between 110W and 118W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 07N100W to 10N110W to 1010 mb low pressure near 08N117W to 10N123W to 09N127W. The ITCZ continues from 09N127W to 07N131W to 07N140W. Scattered moderate convection is occurring within 90 nm of the ITCZ west of 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information about the upcoming gale force gap wind event in the Gulf of Tehuantepec. Scatterometer data between 1600-1800 UTC shows moderate to fresh NW to N winds over the central and southern Gulf of California southward to near Las Tres Marias. A weak high pressure ridge off the Baja California offshore waters is supporting gentle to moderate northerly winds offshore of Baja California Sur. Light and variable winds prevail off the coast of southern Mexico. A set of large NW swell will move into the Baja California Norte waters Mon morning with 8-11 ft seas expected through Mon night. This swell will continue to propagate SE into the Baja California Sur waters through Tue night before subsiding early on Wed. A weak high pressure ridge will cross 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 winds will resume off the coast of Sinaloa and near the entrance to the Gulf of California by late week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to occasionally strong NE to E winds will pulse across and downstream from the Gulf of Papagayo through Fri. Moderate to locally fresh northerly winds will pulse across the Gulf of Panama through mid week, then diminish by 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... A cold front extends across the NW waters from 30N126W to 24N133W to 21N140W. Partial scatterometer data on either side of the front highlights fresh S to SW winds ahead of the front north of 28N, while fresh W to NW winds prevail behind the front. The front is accompanied by very large NW swell, with earlier altimeter data showing seas greater than 20 ft over the far NW waters. The front will continue to move east across the northern waters and weaken into a surface trough over Baja California offshores Wed into Wed night. The swell associated with the front will spread SE while slowly decaying through late Wed over most of the northern waters. Looking ahead, another set of large NW swell will move into the NW waters Thu and propagate SE through Fri. $$ Reinhart