000 AXPZ20 KNHC 061555 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1408 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 1200 UTC surface analysis and satellite imagery through 1440 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A cold front is expected to enter the NW Gulf of Mexico this afternoon and allow high pressure to build over eastern Mexico tonight and Sat. This will support gale force gap winds over the Gulf of Tehuantepec from late tonight through Sat night. Seas will peak between 12 and 13 ft downstream of the Gulf on Sat night, then subside during the day Sun as wind speeds over the Gulf diminish to around 25 kt. 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 08N74W to 05N98W to 08N115W. The ITCZ continues from 08N115W to 10N134W to beyond 09N140W. Scattered moderate and isolated strong convection is found from 04N to 08N between 77W and 85W, and from 04N to 07N between 103W and 108W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak high pressure ridging SSE just to the W of Baja California is yielding moderate to fresh NW to N winds across the full length of the Gulf of California. Satellite-derived wind data from early this morning showed the strongest winds occurring across the S central portions where seas are building to near 5 ft. These winds will continue and could become locally strong around sunrise Sat before diminishing to moderate Sun. Mainly gentle N to NE winds were indicated by scatterometer across the Baja offshore waters, with strongest winds along the southern coast. A very minor increase in winds is expected across the offshore waters today and tonight. Large NW swell will enter the Baja California Norte waters 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. Farther SE, gentle N to NW winds over the offshore waters near the mouth of the Gulf of California and Cabo Corrientes become NW from near Manzanillo to Puerto Angel. Winds are expected to veer toward the north E of Cabo Corrientes Fri night through Sat but remain gentle. Across the Gulf of Tehuantepec, moderate to fresh N winds will increase tonight and gale force around midnight. Please see the Special Features section above for more details on the Gulf of Tehuantepec Gale Warning. 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 and 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 30N130W to 26N134W to 23.5N140W. Scatterometer data earlier this morning showed moderate to fresh NW to W winds behind the front, with fresh S to SW flow ahead of the front. This front will cross the northern waters through Fri night, then stall and weaken W of 120W 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 around 21 ft near the far NW portion of the discussion area this afternoon. Elsewhere, NW swell in the southern waters will continue to decay. Seas in this region have subsided to below 8 ft and will continue subsiding to around 6 ft by Sun morning. Looking ahead, another cold front will move into the NW corner of the discussion area on Mon, introducing another set of NW swell into the NW waters through the middle of next week. $$ CAM