000 AXPZ20 KNHC 231627 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Dec 23 2022 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 1600 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: A strong Arctic cold front will cross the entire Gulf of Mexico through this evening. Very strong high pressure is building behind the front across eastern Mexico and through the Chivela Pass, resulting in fresh to strong winds returning in the Gulf of Tehuantepec at sunrise this morning. Winds across Tehuantepec will rapidly increase during the next several hours, reaching gale force by early afternoon, then to storm force this evening into early Sat. Gales could then last through at least Tue night. This event will produce a very large plume of winds by tonight, expanding across the Tehuantepec region between 93.5W and 95.5W and extending offshore to near 11N. Very large and steep seas will quickly develop with this gap wind event, peaking at around 20-21 ft tonight through Sat morning. 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 09N74W to 06N82W to 06.5N94W. The ITCZ axis extends from 06.5N94W to 08N104W to 07N122W, then resumes near 06N127W to beyond 05.5N140W. Scattered moderate isolated strong convection is noted from 04N to 07.5N E of 87W, from 07N to 13.5N between 100W and 114W, and from 04N to 09N between 119W and 139W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information about an upcoming storm force gap wind event in the Gulf of Tehuantepec. Northerly wind to around 25 kt have already begun across the immediate waters N of 15N across Tehuantepec and will increase and expand throughout the day. A ridge extends from 1024 mb high pressure centered west of Baja California near 31N125W to Baja California Sur. This pattern is supporting moderate to locally fresh northerly winds across the southern Gulf of California, with gentle breezes elsewhere over Mexican offshore waters north of 20N. Light to gentle breezes persist farther south off southern Mexico as well. Moderate seas are in place across the open offshore waters, except for 1 to 2 ft over the northern Gulf of California. For the forecast, high pressure will remain generally stationary west of the offshore waters through today before weakening and shifting northward over the weekend. The associated ridge will change orientation and build southeastward through Sat, and act to strengthen local winds to moderate to locally fresh across the Baja offshore waters, and fresh to locally strong inside the Gulf of California. High pressure will weaken Sun night through Mon to produce a weakening trend in winds across the waters north of Cabo Corrientes. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E gap winds are occurring over the Gulf of Papagayo region, and extend offshore to 89W, with 5-7 ft seas. Light winds prevail elsewhere north of 10N, where seas are 4-6 ft in mixed swell including E swell from the Gulf of Papagayo. Elsewhere winds are moderate or weaker with seas 3-5 ft. For the forecast, fresh to strong NE to E gap winds will continue to pulse in the Papagayo region through the rest of the forecast period. Gentle to occasionally moderate winds will continue elsewhere for the next several days. Large NW swell is expected in the Guatemala offshore zone early Sat through at least Mon night due to the large area of gale to storm force winds that will develop across the Gulf of Tehuantepec region over the next several days. REMAINDER OF THE AREA... High pressure dominates the waters north of 20N. Farther south, a trough is analyzed near 123W in the deep tropics from 02N to 10N, supporting scattered showers and isolated thunderstorms within 90 nm of the trough axis where it intersects the ITCZ. Overnight scatterometer satellite data and local buoy data indicated fresh to strong winds near the trough axis as well. Elsewhere, a broad area of fresh trade winds persist north of the ITCZ to 15N west of 118W. Overnight altimeter satellite passes indicated large area of 7 to 10 ft wave heights mainly west of 125W. These large seas are mostly due to W-NW swell over the region, but include short period waves in the trade wind belt deeper into the tropics. Farther east, overnight scatterometer satellite data indicated fresh E winds near a wave along the ITCZ near 105W. A concurrent Jason-3 altimeter pass indicated seas of 8 to 9 ft in this area as well. This feature is associated with a mid to upper trough northeast of the region. For the forecast, the feature near 105W will move westward along 10N over the next several days, with fresh to strong winds and rough seas persisting within 90 nm to its north. Little change is expected elsewhere, with trade winds and 7 to 10 ft seas persisting. Seas will build north of 25N and west of 130W by late Sat/early Sun as a new round of NW swell moves into the area. Southerly winds will increase Sun as well in this area, ahead of a cold front approaching from the northwest. The front will likely stall before reaching the discussion area but swell will continue to build through early next week along with shorter period waves from the increased southerly flow, reaching as high as 15 ft Sun night. Meanwhile farther east, northeast swell will emerge from storm force gap winds in the Gulf of Tehuantepec, mixing with easterly swell from Papagayo, with combined wave heights of 8 to 11 ft reaching as far west as 105W from 05N to 12N. $$ Stripling