000 AXPZ20 KNHC 120924 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Dec 12 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong surface high pressure building in the wake of a cold front moving across the western Gulf of Mexico tonight will support the next gale force gap wind event in the region of Tehuantepec. Strong N winds will begin to spill across Tehuantepec during the next several hours, and rapidly increasing to near gale force by Sun morning. Gale force winds are expected across Tehuantepec N of 15N during the afternoon hours and will continue through near midnight Sun, and then diminish to around 30 kt through Mon morning. Peak seas during the highest winds are expected to build up to 11 ft. Please refer to the latest High Seas Forecast product issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Heavy showers and tstorms have intensified tonight across the western slopes of the mountainous of extreme NW Colombia and across the adjacent nearshore coastal waters within 60 nm of the coast. 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 moved over the far eastern Tropical Pacific, and will support convection that develops across this area. This may result in areas of deep convection tonight 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 10N74.5W to 08.5N79W to 10.5N85W to 06.5N97W to 06N107W. The ITCZ extends from 06N107W to 08N118W to beyond 08.5N140W. Scattered strong convection is along the coast of Colombia from 05N to 07N. Scattered moderate isolated strong convection is from 06N to 08.5N between 79W and 91W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO See the Special Features section above for details on an upcoming gale force gap wind event in the region of Tehuantepec. Gentle to moderate northerly winds are across the Baja California offshore waters tonight with 5-8 ft seas in NW swell. A tight pressure gradient between a ridge to the northwest of Baja California and a trough along western Mexico is generating fresh NW winds across the Gulf of California, and strong winds across central portions. Seas in the Gulf range 4-7 ft. Strong winds surrounding the Cabo Corrientes offshore waters earlier have diminished to fresh, while seas are 6-7 ft. Light to gentle variable winds prevail elsewhere across the S and SW Mexico offshore waters with seas to 5 ft in mixed NW and SW swell. Winds will weaken Sun offshore of Cabo Corrientes as a trough shifts westward away from the coast. Moderate to fresh winds will then return to Cabo Corrientes and adjacent waters Mon night through Wed. The next strong gap wind event in the Tehuantepec region is forecast to begin early Sun with strong winds rapidly increasing to gale force by Sun afternoon. Gale conditions are forecast through Sun night, however strong to near gale force winds are forecast to continue through the Wed night. Looking ahead, a strong cold front will move into the northern waters Tue. Fresh to strong SW winds are expected ahead of the front across the offshore waters N of 27N Tue afternoon before the front arrives Tue night. NW swell will move into the northern offshore waters early Tue and raise seas 8 to 12 ft by Tue afternoon, and peak at 14-15 ft across the waters of Baja Norte Wed morning. Meanwhile, similar strong SW to W gap winds will develop inside the N Gulf of California Tue and reach around 30 kt Tue evening, when seas will build to 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR Fresh gap winds continue across the Papagayo region with seas to 6 ft. Moderate N winds continue across the Gulf of Panama where seas are 3-5 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 heavy rainfall over the Colombia and Panama offshore waters through the weekend. Fresh NE gap winds will continue to pulse to strong at night across the Papagayo region through Wed. Gentle to moderate winds will prevail elsewhere the next several days. REMAINDER OF THE AREA... High pressure ridging dominates the forecast waters N of 14N and W of 110W, centered on a 1023 mb high near 30N128W. The remnants of a cold front in the form of a shear line has become ill defined W of 120W along 21N to 22N. However fresh E winds 15 to 20 kt from 21N to 25N are mixing with N swell to produce seas of 7-8 ft across this area. A low level trough has developed from 14N120W to 17.5N138W. The pressure gradient between it and high pressure to the north is also producing a zone of 15-20 kt winds within 120 nm N of this trough, and scattered moderate isolated strong convection. Elsewhere mainly gentle to moderate NE to E winds are N of 25N with seas to 7 ft in NW swell. Moderate to fresh SE winds are S of the ITCZ W of 118W with seas 6 to 7 ft. A strong 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 Tue afternoon. Seas are expected to peak at 18-19 ft across the far NW waters early Tue. $$ Stripling