000 AXPZ20 KNHC 110349 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0250 UTC. ...SPECIAL FEATURES... Heavy showers and scattered tstms occurring earlier this afternoon across the mountainous interior of NW Colombia and adjacent coastal waters to 81W have diminished significantly in the past few hours as strong upper level SW winds are producing vertical wind shear across the area. However, active weather is forecast to resume 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 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 10N75W to 09.5N82W to 06N91W to 08.5N113W to 12N116.5W. The ITCZ extends from 13N122W to 07.5N140W. Scattered moderate convection is noted from 03N to 06N E of 79.5W. Scattered moderate isolated strong convection is noted from 14.5N to 17N between 120W and 130W, and from 08N to 10N between 131W and 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO A cold front has become stationary across the area this evening, exiting NW Mexico near Kino Nuevo then SW across the Gulf of California, across central Baja California, exiting into the Pacific waters near Punta Abreojos, then continuing to beyond 25N120W. Moderate to fresh northerly winds follows the front with seas to 4 ft in the northern Gulf and seas in the 6 to 9 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, while fresh northerly winds surround Cabo Corrientes where seas are 6-7 ft. 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 stationary front will gradually dissipate across the area Sat, 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 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. The stationary front the Baja California offshore waters extends as a shearline from 25N120W to near 24N129W. Moderate to fresh N to NE winds are N 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 120W, where seas are 6 to 8 ft. Diffluent flow aloft to the E 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 17N116W to 09N121W. 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 night as the pressure gradient continues to weaken. The shearline e 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 18-20 ft across the far NW waters early Tue. $$ Stripling