000 AXPZ20 KNHC 210945 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 0405 UTC Wed Dec 21 2022 Corrected Special Features section 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 0330 UTC. ...SPECIAL FEATURES...Corrected Gulf of Tehuantepec Gale Warning: High pressure ridging is building southward along the eastern slopes of the Sierra Madre Mountains as a central Gulf of Mexico low pressure system shifts eastward. As this happens, the gradient in southeastern Mexico is tightening as cold dense air surges southward toward the Gulf of Tehuantepec gap region. The resultant surge of northerly winds out over Tehuantepec has begun as of this evening, with gale-force winds to 35 kt. These conditions are expected to last through Wed afternoon. Seas are forecast to build to 9-13 ft with these winds. Northerly winds will then gradually diminish Wed night. Seas will subside to below 8 ft by sunrise Thu. Please read the latest High Seas Forecast issued by the the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Gale Warning in NW Part of area: A gale force low pressure center well west of the area contains an associated cold front along 148W. The low and associated front will shift northeastward through Thu, remaining NW of the forecast area. However, southerly winds to the east of the cold front are forecast to reach strong to near gale force, with a small area of gale force winds on Wed north of 27N and west of 137W. Seas of 15-18 ft are expected within the area of gale force winds in W swell. Winds will diminish in the area Wed night, and seas will subside to below 12 ft by Thu afternoon. Please read the latest High Seas Forecast issued by the the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from low pressure in northwest Colombia near 11N74W southwestward to 08N79W and northwestward to 10N85W, then to 07N92W and to 06N101W. The ITCZ extends from 06N101W to 07N110W to 07N124W to 09N133W and to beyond 09N140W. Scattered moderate to isolated strong convection is within 60 nm north of the ITCZ between 138W-140W. Scattered moderate convection within 60 nm north of the ITCZ between 130W-133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about a recently started gale event in the Gulf of Tehuantepec that is expected to last through Wed afternoon. High pressure ridging is present over the western portion of the Baja California offshore waters. Moderate N to NE winds are across the Baja California offshore waters. Fresh to strong NW to NNW winds are occurring in the Gulf of California south of 30N with 4-6 ft seas, while moderate to fresh winds prevail in the northern Gulf with 2-4 ft seas. Gentle or weaker winds and 3-5 ft seas prevail elsewhere. For the forecast, the gale-force northerly winds in the Gulf of Tehuantepec are forecast to last through Wed afternoon before diminishing Wed night into early Thu. Fresh to strong NW winds will continue in the Gulf of California through Wed before diminishing Wed night. Looking ahead, the next Tehuantepec gap wind event is expected Fri through the weekend. Gales could last from Fri afternoon through Sun night, with storm force winds possible on Fri night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast to east winds are in the Gulf of Papagayo region, while moderate to fresh east winds extend offshore of Papagayo southwestward to 90W. Seas are 5-6 ft over these waters. Light to gentle winds prevail elsewhere north of the monsoon trough off of Guatemala and El Salvador, with seas to 4 ft. Gentle S-SW winds and seas of 3-5 ft are present south of the monsoon trough. For the forecast, fresh to strong northeast to east winds will continue to pulse in the Papagayo region through the rest of the forecast period. The strongest winds are mainly expected at night and into the mornings, when seas are expected to build to 6 to 7 ft. Gentle to occasionally moderate winds will continue elsewhere through the remainder of the week and the upcoming weekend. Seas will build to 6 to 8 ft on Wed well offshore western Guatemala due to swell from a Gulf of Tehuantepec gap wind event. A larger swell can be expected there Fri night through the weekend due to a stronger Gulf of Tehuantepec gap wind event. REMAINDER OF THE AREA... Please read the special features section above for details on a gale warning in the NW corner of the forecast area, from 27N to 30N between 137W and 140W. A cold front is well west of the area along 146W. Latest ASCAT data from Tuesday afternoon depicts strong SSE winds north of about 26N and west of 138W, although strong winds likely extend as far south as 22N there. Seas of 7-10 ft are likely occurring with these strong winds. A ship observation from several hours ago reported combined seas of 9 ft near 26N138W. Scattered showers and isolated thunderstorms are noted along and near 140W N of 19N. Elsewhere, high pressure ridging prevails over the area between 115W and 135W from 20N to 30N. Light to moderate anticyclonic winds and 3-6 ft seas continue over this area. Fresh trade winds are present from the ITCZ from 20N and west of 118W with 5-8 ft seas. For the forecast, moderate to fresh trade winds S of 20N and W of 120W are expected to change little through Thu. The low pressure and cold front described above in the special features section will shift northeastward through Wed night, at which time fresh to strong S-SW winds are expected to be confined to N of 27N and between 135W-140W along with seas of 8-12 ft between 135W-137W, and higher seas of 12-16 ft between 137W-140W. NW swell generated from the low pressure system W of the area will propagate southeastward merging with an existing area of swell that is between 122W-135W from 07N to 13N by early on Thu. The leading edge of the entire swell area is expected to reach near 130W and S to near 06N at that time, with resultant seas in the range of 8-11 ft. The swell area is forecast to gradually expand eastward to near 121W by Fri. $$ Aguirre