000 AXPZ20 KNHC 111005 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Dec 11 2024 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 0900 UTC. ...SPECIAL FEATURES... Tehuantepec Storm Warning: The most significant gap wind event thus far of the season will occur across the Gulf of Tehuantepec from early this morning through Fri morning as a strong cold front sweeps southeastward across the Gulf of Mexico and southeastern Mexico, followed by building high pressure. Winds will quickly reach gale-force around sunrise, then rapidly increase to strong gale-force by this afternoon, and briefly increase further to storm-force late this afternoon through evening. Seas will quickly build to 18 to 22 ft this evening and tonight. Gale-force winds and high seas are expected to extend to near 300 NM from the Tehuantepec coast by Wed evening. Gales are then forecast to persist through early Thu evening. Winds will gradually diminish to strong to near-gale force strength Thu night and continue to pulse at night through early next week. Gulf of California Gale Warning: A strong pressure gradient continues early this morning between a 1036 mb high over the Great Basin of the western U.S. and troughing along the Sierra Madre Occidentales of northwest Mexico. This pattern is supporting strong to gale force N to NW winds through the entire length of the Gulf of California. Recent satellite derived scatterometer winds showed winds to minimal gale-force across central portions of the Gulf, where peak seas are 10 to 12 ft. Fresh to strong N winds also surround Cabo San Lucas, and are offshore of Cabo Corrientes. This blast of strong northerly winds is also forcing strong NE gap winds across most of the Baja Peninsula, spilling into the Pacific waters of Sebastian Vizcaino Bay and southwest of Punta Eugenia, as well as offshore of Punta Abreojos. Seas of 8 to 12 ft prevail from the northern Gulf along 30N into the southern Gulf waters. The strong high pressure north of the Gulf will weaken this afternoon through tonight, leading to quickly diminishing winds and seas across the basin. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N75W to 10N87W to 06.5N99W. The ITCZ extends from 06.5N99W to 08N111W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 06.5N to 08.5N between 108W and 113W. Widely scattered moderate convection is noted from 13N to 17N between 126W and 136W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for information on the Gulf of Tehuantepec Storm Warning and the Gulf of California Gale Warning. Elsewhere, a weak ridge extends southeastward across the waters off of Baja California and southwestern Mexico. Moderate NE winds generally prevail across the Baja offshore waters, outside of the finger-like jets of NE gap winds spilling out of the Gulf. Seas are 5 to 7 ft in NW swell across the Baja offshore waters except 8 to 9 ft within the strong gap wind areas. East of Cabo Corrientes light to gentle winds currently prevail to Salina Cruz, where seas are 4 to 6 ft in prevailing SW swell. For the forecast, aside from the storm-force winds developing across and offshore of the Gulf of Tehuantepec, winds and seas will gradually diminish across the Gulf of California, the Baja California offshore waters, as well as the waters offshore of southwestern Mexico this evening through Thu. Gale conditions are expected to end across Tehuantepec Thu evening, with strong winds continuing there through the weekend. A new cold front moving through the eastern Pacific off the coast of California will lead to moderate to locally fresh N to NW winds north of Punta Eugenia Thu night into Fri. Looking ahead, high pressure building into the region from the NW this weekend will support moderate to locally fresh N to NW winds north of Cabo Corrientes. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE to E winds are across the Gulf of Papagayo region, where seas are 5 to 6 ft. Otherwise, moderate S to SW winds and seas of 4 to 6 ft are noted south of the monsoon trough, along about 09N, with gentle to locally moderate winds occurring to the north. For the forecast, fresh NE gap winds across the Gulf of Papagayo will increase to strong this evening through Thu, then pulse to strong at night through Fri night, as a strong pressure gradient between the Colombian low and an approaching Caribbean cold front develops across the region. Strong winds and very rough seas along the eastern edge of a Tehuantepec storm-force wind event will impact the offshore waters of southwestern Guatemala Wed night through early Fri, with associated NW swell spreading to offshore of Papagayo by Thu afternoon. Winds offshore of Guatemala will diminish Thu through Thu night with seas slowly subsiding Thu night through Fri. Moderate to locally fresh N winds will also pulse in the Gulf of Panama through this weekend. Otherwise, gentle to moderate S to SW winds and moderate seas will prevail south of the monsoon trough, with gentle winds and slight seas occurring north of the trough, away from the gap winds. ...REMAINDER OF THE AREA... High pressure centers of 1024 to 1025 mb are located on either side of a weak cold front drifting eastward along 30N and 137W. The pattern to the south is producing a broad ridge extending across much of the waters north of the ITCZ and W of 108W. Moderate to fresh trades are occurring south of 22N and west of 115W, with locally strong NE to E winds occurring between 13N and 21W west of 131W. NW swell moving through the regional waters is combining with seas developed in the area of fresh to strong winds to produce seas of 10 to 12 ft there. North of 21N, gentle to locally moderate winds are noted. NW swell is supporting seas of 8 to 10 ft elsewhere north of 20N and west of 120W, except for the peak of new swell arriving into the far NW waters, where recent satellite altimeter data showed seas 10-14 ft. South of the ITCZ, moderate to locally fresh SE winds and seas of 4 to 7 ft prevail. For the forecast, the NW swell will propagate southeastward over the next several days, with this swell combining with trade wind swell along and north of the ITCZ. Rough seas are anticipated north of 09N and west of 110W this morning, and north of 07N and west of 118W by Thu morning. Peak seas around 12 ft are expected in the far western waters between 10N and 20N west of 135W. Fresh to strong trades winds will continue from north of the ITCZ to 20N, west of 120W. New NW swell across the far NW waters this evening is expected to peak at 10-13 ft this morning before slowly subsiding. Farther east, strong NE to E winds and rough to very rough seas will develop downwind of the Gulf of Tehuantepec and Gulf of Papagayo Wed night through Thu night, with the strongest winds from Tehuantepec extending SW into the waters north of 08N and east of 107W. Rough seas of 8 to 12 will extend well SW of Tehuantepec and reach from 04N to 14N and E of 110W by early Fri. $$ Stripling