000 AXPZ20 KNHC 111549 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Dec 11 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 1550 UTC. ...SPECIAL FEATURES... Heavy showers and tstms prevail across the mountainous interior of NW Colombia and to the adjacent coastal waters to 79W. Active weather is forecast to continue across NW Colombia and extend across the Colombia and Panama offshore waters through the weekend. An energetic upper level trough has begun to move eastward across the far eastern Tropical Pacific, and will support convection that develops across this area. This may result in areas of deep convection late Sat through early Mon, with rainfall totals of 3 to 10 inches possible across the western slopes of the mountains and adjacent coastal zones. Rough marine conditions are also expected during this period and mariners should exercise caution. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 08N85W to 05N96W to 07N113W. The ITCZ extends from 09N121W to 09N135W to beyond 09N140W. Scattered moderate convection is from 13N to 17N between 119W and 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO The remnants of a cold front are analyzed as a surface trough from Las Tinajas in Baja California Sur to 23N117W. Moderate northerly winds follows the trough with seas in the 6 to 8 ft range. A tightening pressure gradient between a ridge to the northwest of Baja California and a trough along western Mexico is generating moderate to locally fresh winds along the Gulf of California all the way south to the offshore waters of Jalisco, while strong northerly winds surround Cabo Corrientes where seas are 6-7 ft. Light to gentle variable winds are elsewhere across the S and SW Mexico offshore waters with seas to 5 ft in mixed NW and SW swell. The cold front will continue moving southward across Baja California and the adjacent waters and gradually dissipate as it reaches near Cabo San Lucas this afternoon, while a surface trough develops along the Gulf of California. The pressure gradient between the trough and moderate high pressure in the wake of the front will generate moderate to fresh winds along the Baja California offshores, the southern half of the Gulf of California all the way south to Jalisco offshore waters through Sat. Locally strong winds are forecast near Cabo Corrientes through Sat evening, where seas will build to around 8 ft. Otherwise, strong N gap winds will develop Sat night in the Gulf of Tehuantepec, with near gale conditions expected Sun and gale conditions possible Sun night. Strong to near gale force winds will then prevail through the middle of next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh to strong gap winds continue across the Papagayo region with seas to 7 ft. Moderate to locally fresh N winds continue across the Gulf of Panama to 06.5N, where seas are 4-5 ft. Moderate S to SW winds are south of the monsoon trough with seas to 6 ft in SW swell. Light to gentle variable winds are elsewhere. Otherwise, see the Special Features Section for details on significant rainfall expected over the Colombia and Panama offshore waters through the weekend. Fresh NE gap winds will continue to pulse to near strong at night across the Papagayo region through the middle of next week. Gentle to moderate winds will prevail elsewhere the next several days, except for onshore SW to W winds pulsing to fresh winds across the offshore waters of southern Colombia and Ecuador early Sat through Sat evening. REMAINDER OF THE AREA... High pressure ridging dominates the forecast waters N of 16N and W of 105W, centered on a 1028 mb high near 33N131W. The cold front across the Baja California offshore waters extends as a shearline from 24N120W to near 24N130W. Moderate to fresh N to NE winds are north of the front with seas 7 to 10 ft in NW swell. Lower pressure along the ITCZ combined with the ridge to the north is producing moderate to fresh NE to E trade winds north of the ITCZ to around 24N and west of about 118W, where seas are 6 to 8 ft. Diffluent flow aloft to the E of a middle to upper level trough, continues to support an area of showers and isolated tstms over the central tropical waters where a surface trough is analyzed from 17N117W to 08N120W. Gentle to moderate winds are occurring elsewhere N of the ITCZ, with seas of 5 to 7 ft. Moderate to fresh SE winds are S of the ITCZ W of 112W with seas 6 to 7 ft. The fresh trade winds and seas around 8 ft in the west-central waters south of the ridge will gradually diminish and decay through Sat night as the pressure gradient continues to weaken. The shearline will continue to weaken before dissipating Sat. A second cold front is forecast to move across the far NW waters Sun through early next week, accompanied by very large NW swell. This large NW swell will enter the NW waters Sun night and move east of 120W by Mon evening. Seas are expected to peak at 18-19 ft across the far NW waters early Tue. $$ Ramos