000 AXPZ20 KNHC 060311 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0310 UTC Fri Dec 6 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: A cold front is expected to move across the Gulf of Mexico Fri through Sat, and high pressure will build over eastern Mexico behind the front. This will support gale force gap winds over the Gulf of Tehuantepec beginning late Fri night and continuing through Sat night. Seas will build to 12-13 ft downstream of the Gulf on Sat night, then subside on Sun as wind speeds diminish to fresh to strong speeds. Looking ahead, another gale force gap wind event could affect the Gulf of Tehuantepec during the middle of next week, although the timing remains uncertain given the lack of model agreement. 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 more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 05N95W to 1011 mb low pressure near 07N104W to 09N120W, then resumes from 11N129W to 10N136W. The ITCZ extends from 10N136W to beyond 08N140W. Scattered moderate convection is noted within 60 nm of the monsoon trough between 81W and 83W, within 120 nm of the monsoon trough between 102W and 106W, and within 90 nm north of the monsoon trough between 131W and 136W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on the Gulf of Tehuantepec Gale Warning. Fresh northerly winds likely continue over the Gulf of Tehuantepec this evening. Moderate NW winds prevail over the central and southern Gulf of California. Elsewhere, light to gentle breezes persist across much of the offshore waters under a weak pressure pattern. Fresh NW to N winds will develop over the central and southern Gulf of California later tonight and persist through Sat night. Large NW swell will enter the Baja California Norte waters on Sat, with offshore seas building to 8-12 ft by Sat night. This swell will continue spreading SE across the region Sat night through Sun night, then decay Mon into Mon night. The pressure gradient over Baja California will strengthen early next week, resulting in fresh northerly winds offshore and over the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong NE to E winds will pulse across and downstream of the Gulf of Papagayo through Tue, with seas peaking between 8-9 ft downstream of the Gulf each morning. SW winds will freshen off the coast of Colombia late tonight through Sat. Otherwise, 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. REMAINDER OF THE AREA... A cold front extends across the NW waters from 30N133W to 25N140W. Scatterometer data from earlier today showed fresh to strong NW winds behind the front, with fresh SW flow ahead of the front. This front will cross the northern waters through Fri night, then stall and weaken on Sat. Very large NW swell associated with this system will propagate SE through the weekend. Seas will build to greater than 12 ft over the northern waters Fri through Sat, peaking in excess of 20 ft over the far NW portion on Fri. Elsewhere, decaying NW swell lingering over the southern waters will continue subsiding overnight, with seas becoming less than 8 ft by Fri morning. Looking ahead, another cold front will move into the NW portion on Mon, bringing another set of NW swell into the northern waters through early next week. $$ Reinhart