000 AXPZ20 KNHC 040904 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jan 4 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 0820 UTC. ...SPECIAL FEATURES... Large Area of High Seas: NW swell generated by a strong frontal system affecting the Pacific coast of the U.S. and Baja California continues to propagate southeastward into the regional Pacific waters N of 20N and W of 112W tonight. This is ongoing behind a cold front moving into the region that currently extends from the central Gulf of California southwestward across central Baja California to near 23N130W. Seas north of the front are presently 8 to 16 ft in NW swell. This swell will continue to spread southeastward and across the remaining Baja California waters tonight and Thu, behind the cold front, as it reaches Cabo San Lucas and adjacent offshore waters Thu evening before dissipating. NW swell associated with this system will peak at 12 to 17 ft across the Baja Norte offshore waters throughout Thu morning, accompanied by strong N-NW winds behind the front. On Thu and Thu night, seas of 12 ft and greater will eventually cover a large area that will extend from 23N to beyond 30N, between the Baja California coastal waters and 130W. Wind and seas will begin to subside late Thu night through Fri, with seas falling below 12 ft by Fri late afternoon. However, new NW swell will move into the regional waters W of 130W Fri morning and produce another large area of seas 12 ft and greater, covering the area between 119W and 140W late Fri through Sat night. Meanwhile, strong high pressure behind the cold front has settled just N of the area near 32N136W, and is expected to remain nearly stationary through Fri before drifting NW over the weekend. The pressure gradient between this high and the ITCZ will continue to produce a large area of fresh to strong trade winds between the ITCZ and 24N and W of 120W through Sat morning. This will produce large and steep seas in E-NE trade wind swell. This trade wind swell will merge with incoming NW swell to produce a large area of combined seas of 12 ft and greater from 08N to 22N and W of 129W Thu morning through Thu night. Peak seas in the trade wind zone are expected to build to 14 ft Thu. New large NW swell will then enter the regional waters early Fri, and act to expand the area of 12 ft seas to beyond 30N Fri through Sat morning, before seas begin to subside very slowly Sat through late Sun. Seas W of 130W are forecast to finally subside below 12 ft by late Sun afternoon. Please refer to the High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N74W to 07N93W to 08N101W to 07N104W. The ITCZ extends from 06N105W to 04N114W to 07.5N133W to beyond 06N140W. Scattered moderate convection is noted from 02.5N to 06.5N E of 92W. Scattered moderate isolated strong convection is noted from 04.5N to 09.5N between 99W and 110W, and from 04N to 10N between 121W and 136W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front continues to move across NW Mexico and the adjacent waters tonight, and currently extends from the central Gulf of California southwestward across central Baja California to beyond 24N120W. Surface ridging anchored by a 1034 mb high near 32N136W extends southeastward into the area, behind the cold front. The associated pressure gradient is supporting gentle to moderate NW to N winds S of the front to offshore of Cabo Corrientes, where seas are 6 to 7 ft in NW swell. N of the front, strong NW winds prevail across the area E of 120W, as verified by recent satellite scatterometer data. Strong W to NW gap winds are also bleeding into northern and central portions of the Gulf of California. Seas across these Baja offshore waters are 8 to 14 ft, and as high as 5 ft in the northern Gulf of California. Gentle W to NW winds are occurring elsewhere inside the Gulf of California south of the front, with seas of 3 to 4 ft. Elsewhere in the S and SW Mexican offshore waters, winds are light to gentle with seas in the 4 to 6 ft range in W to NW swell. A cold front moving across the Gulf of Mexico has induced a pulse of strong northerly gap winds across the Gulf of Tehuantepec N of 15.5N. For the forecast, the cold front will continue to move southeastward tonight through Thu, and gradually dissipate offshore of Cabo San Lucas and Baja Sur by Thu evening. Fresh to strong NW to N winds will follow in behind the front to the north of Cabo San Lazaro and persist through Thu evening before diminishing Thu night. Fresh to strong W gap winds will briefly occur in the northern and central Gulf of California through Thu morning with and directly behind the front. High seas in mixed NW swell will follow this front, affecting the offshore waters of Baja California through Fri. Seas across Baja Norte will peak at 12 to 17 ft throughout Thu morning, with seas to 12 ft reaching as far S as 23N Thu evening. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to locally fresh E gap winds prevail across the Papagayo region, and extend offshore to near 88W, with seas to 6 ft. Further offshore, seas are to 7 ft in mixed NE and NW swell. Moderate N to NNE winds continue in the Gulf of Panama N of 06N with seas to 5 ft. Light to gentle winds are ongoing across the Costa Rica, El Salvador and Guatemala offshore waters where seas are in the 4-6 ft range in W to NW swell. Between the coast of Ecuador and the Galapagos Islands, winds are gentle to moderate from the south, with seas 6 to 7 ft in W to NW swell. For the forecast, moderate NE to E winds will continue to pulse to fresh at night in the Papagayo region through Sat as a ridge N of the area weakens. Moderate northerly winds will persist across the Gulf of Panama through Sat. Otherwise, a weak pressure gradient will result in light to gentle winds across the rest of the area through the end of this week. ...REMAINDER OF THE AREA... A cold front extends from central Baja California Norte near 27N113W to 24N120W to 23N130W. The front is followed by fresh to strong NW to N winds and seas in the 8 to 16 ft range E of 124W. Seas of 6 to 9 ft prevail ahead of this front extending across the Baja California offshore waters. Across the NW waters W of 124W, moderate to fresh NE to E winds are noted with seas of 9 to 16 ft in NW swell. Fresh to strong NE to E trades are ongoing N of the ITCZ to 24N and west of 120W. Seas are in the 8 to 12 ft seas over this area. For the forecast, the cold front will move SE and reach the central Gulf of California to Cabo San Lazaro to 21N124W by Thu morning. Large NW swell filling in behind this front will build seas to 12 to 16 ft across the waters north of 24N through Thu. Fresh to strong trade winds between the ITCZ and 25N, and west of 120W, will increase to strong and expand in areal coverage through Fri, as strong high pressure persists just NW of the area. This pattern will produce seas of 11 to 15 ft across that area. See the special features section above for more information. $$ Stripling