000 AXPZ20 KNHC 161604 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Dec 16 2020 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... Gulf of Tehunatepec Gale Warning: A gap wind event is expected to begin in the Tehuantepec area late this afternoon, continuing through Friday. Strong northerly winds will increase to gale force this evening as a cold front moves across the western Gulf of Mexico. Gale conditions and building seas to 12-14 ft will diminish by Fri morning. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 06N95W to 07N110W. The ITCZ continues from 07N110W to 09N121W to beyond 07N140W. Scattered moderate convection is noted off the coasts of Panama and Colombia near the monsoon trough from 05N to 08N between 77W to 83W. Scattered moderate convection is along and north of the ITCZ from 07N to 13N between 118W to 136W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore forecast waters of Baja California. The pressure gradient between the ridge and lower pressures over mainland Mexico is resulting in moderate to fresh northerly winds west of the Baja California peninsula. Large long period NW swell propagating across this region is supporting seas to 08-10 ft. The swell west of Baja California will slowly subside through Fri. A cold front will push south of southern California into Baja California Thurs evening. The front is expected to weaken as it pushes farther south. Gulf of California: Fresh to strong NW-N winds will prevail in the Gulf of California through Thurs. Winds will return to gentle by Thurs evening and will continue through Fri.As a cold front enters the region on Fri, winds will increase to fresh NW-N winds which will prevail through the weekend. Light winds are expected in the Gulf of Tehunatepec today then rapidly increase to gale-force this evening. Please see the Special Features section for more details. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to strong NE-E winds are expected across the Papagayo region Thu through Sun as high pressure builds in the western Caribbean. Northerly fresh winds will pulse across Gulf of Panama Thu night and Fri night. Elsewhere, gentle to moderate S-SW winds will prevail south of the monsoon trough with mainly gentle to moderate N-NE winds north of the trough axis. REMAINDER OF THE AREA... A 1027 mb high pressure located near 32N130W extends a ridge southeastward across the northern forecast waters to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ will continue to support a large area of fresh trade winds, with the strongest trades expected south of the high, between 120W and 140W. Seas are currently 9 to 11 ft in long- period NW swell. Winds and seas will gradually diminish across the entire area through early Thu as the high pressure weakens ahead of an approaching cold front. The front will weaken along 30N on Thu, and high pressure will re- intensify north of the area on Fri. $$ Reinhart