000 AXPZ20 KNHC 060937 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A cold front is expected to move across the Gulf of Mexico Fri through Sat, with high pressure building 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 during the day Sun as wind speeds 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 09N74.5W to 07.5N79W to 09N86W to 05.5N91W to 08.5N116W. The ITCZ extends from 08.5N116W to 11N132W to beyond 08N140W. Scattered moderate isolated strong convection is noted from 02.5N to 08N between 77W and 114W, and from 10N to 15N between 118W and 135W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Weak high pressure prevails across the offshore waters of Baja California tonight, yielding moderate to fresh NW to N winds across the full length of the Gulf of California. Recent scatterometer winds sampled the Gulf and showed the strongest winds occurring across the southern portions where seas are building to near 5 ft. These winds will strengthen very slightly overnight and continue through Sat afternoon before diminishing slightly. Mainly gentle N to NE winds were depicted by scatterometer across the offshore waters, with strongest winds along the coast. A very minor increase in winds is also expected across the offshore waters Fri through Fri 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. Farther southeast, gentle N to NW winds prevail across the offshore waters from the mouth of the Gulf of California beyond Cabo Corrientes then become more westerly from near Manzanillo to Puerto Angel. Winds are expected to become more northerly E of Cabo Corrientes Fri night through Sat but remain gentle. Across the Gulf of Tehuantepec, fresh northerly winds continue tonight before diminishing modestly during the day Fri. Winds will then begin to increase Fri night, reaching 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 8-9 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 30N131W to 25N140W. Scatterometer data overnight showed fresh to strong 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 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. $$ Stripling