310 AXPZ20 KNHC 102151 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Fri Dec 10 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 1800 UTC surface analysis and satellite imagery through 2150 UTC. ...SPECIAL FEATURES... Heavy showers and scattered tstms are ongoing across the mountainous interior of NW Colombia, and extend westward across the regional waters to 82W. 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 is expected to move eastward across the far eastern Tropical Pacific this weekend, and will enhance any convection that develops. This may result in areas of strong convection late Sat through 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 09N85W to 10N115W. The ITCZ extends from 10N123W to 07N40W. Aside from the convection mentioned in the Special Features off the coast of Colombia, scattered moderate convection is from 10N to 17N between 107W and 115W, and from 07N to 11N between 126W and 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A cold front continues to move across the northern Gulf of California to Punta Prieta in Baja California Sur to 26N118W where it starts to dissipate. Moderate to fresh northly winds follows the front with seas to 5 ft in the northern Gulf and seas in the 5 to 8 ft range across the Baja California Norte offshores. A tight pressure gradient between high pressure over SW Mexico, a ridge extending across the Baja offshores, and a pre-frontal trough is generating moderate to fresh winds at the entrance of the Gulf of California and south of Cabo San Lucas to the offshore waters of Jalisco. Seas are in the 4 to 6 ft in this region being supported by mixed SW and NW swell. 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 move S-SE and dissipate across Baja California Sur late today, 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 tonight through Sun, 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 possible Sun and gale conditions Sun night. Strong to near gale force winds will then prevail through the middle of nect week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh to strong winds gap winds continue across the Papagayo region with seas to 7 ft. Moderate to locally fresh N winds are occurring in the Gulf of Panama with seas to 6 ft. Gentle to moderate S to SW winds are south of the monsoon trough with seas to 5 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 17N and W of 111W. A cold front is moving across the Baja California Norte offshore waters and extends from 27N120W to 27N127W. Moderate to fresh N to NE winds are N of the front with seas to 8 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 130W, where seas are 7 to 8 ft. Diffluent flow aloft to the E of of a middle to upper level trough, continues to support a broad area of showers and isolated tstms over the central tropical waters where a surface trough is analyzed from 14N113W to 11N117W. 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 117W with seas 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 as the pressure gradient continues to weaken. The cold front will continue to move S-SE today while weakening before dissipating tonight. 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 18-20 ft across the far NW waters early Tue. $$ Ramos