000 AXPZ20 KNHC 020311 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0310 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Surface high pressure is building over eastern Mexico tonight in the wake of a cold front crossing the western Gulf of Mexico. 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 by 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 118W south of 16N, moving westward around 10-15 kt. Scattered moderate isolated strong convection is noted from 10N to 15N between 112W and 118W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 08N102W to 10N110W to 1007 mb low pressure near 09N117W to 11N123W to 08N129W. The ITCZ continues from 08N129W to 08N140W. Scattered moderate convection is occurring within 90 nm of the monsoon trough between 109W and 114W, and within 90 nm north of the ITCZ between 124W and 128W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information about the gale force gap wind event commencing tonight in the Gulf of Tehuantepec. Moderate to fresh NW to N winds prevail over the central and southern Gulf of California southward to near Las Tres Marias. Earlier altimeter data showed 8 ft seas west of Cabo Corrientes downstream of these winds. Weak high pressure centered near Guadalupe Island is supporting gentle to moderate northerly winds over the Baja California Sur offshore waters. Elsewhere, 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 and south of 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 slow-moving, weakening cold front extends across the NW waters from 30N126W to 24N132W to 21N140W. Wind speeds are diminishing over the northern waters on either side of the front, but large NW swell continues spreading SE across the NW portion. Altimeter data from 20 UTC revealed 12-18 ft seas north of 25N along 131W. The front will stall and weaken overnight, while the associated swell will continue propagating SE and cover most of the waters west of 115W by Wed while slowly decaying. A secondary cold front or trough developing over the far NW portion will move eastward across the northern waters, then weaken as it crosses the Baja California offshore zones Wed into Wed night. A surface trough or weak low will develop west of the Baja offshore waters Mon night into Tue, briefly produce fresh winds between 120W and 125W into Tue night, then weaken on Wed. Looking ahead, another set of large NW swell will move into the NW waters Thu and propagate SE through Fri. $$ Reinhart