773 AXNT20 KNHC 070442 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Tue Mar 7 2023 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: The next cold front will move south of 31N late Tue, then extend from 31N61W to 28N74W to 29.5N80W late Tue night, and reach from 31N55W to 25N73W by early Wed. Gale force winds are expected on both sides of the front Tue night into Wed north of 27N and east of 68W. The gales will continue eastward late Wed into early Thu between 50W and 35W. This front will send large N swell spreading across Atlantic waters Tue night through Thu night. Seas will reach over 20 ft on Wed north of 30N between 49W and 61W. Atlantic Significant Swell Events: Prior to the event described above, long-period NW swell is currently propagating through the central and eastern waters generating seas in the range of 12 to 16 ft north of 27N between 30W and 62W with a period of 12 to 14 seconds. The swell will be reinforced by a new set of NW to N swell, associated with the cold front described above, which will move into the area late Tue. Swell in excess of 12 ft will propagate as far south as 20N by Thu, impacting waters east of the Bahamas to the central Atlantic. The swell will also impact the NE Caribbean passages and Tropical N Atlantic waters Thu into Fri. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on the gale and swell events. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Sierra Leone near 07N12W to 03N17W. The ITCZ continues from 03N17W to 01S44W. Scattered moderate convection is observed within 240 nm from the ITCZ and from the equator to 10N, east of 30W. GULF OF MEXICO... A surface trough extends across the SW Gulf, supporting gentle to moderate winds west of 90W. A 1018 mb high pressure centered in the NE Gulf dominates the pattern in the eastern Gulf, supporting light to gentle anticyclonic winds. Seas are 1-3 ft across the basin. For the forecast, weak high pressure centered over the NE Gulf will dominate the area through Wed. A cold front will enter the NE Gulf on Wed morning, and extend from the lower Florida Keys to near Mobile, Alabama on Thu morning while dissipating. Another weak cold front will reach the NW Gulf of Fri. CARIBBEAN SEA... The gradient between subtropical high pressure and lower pressure over the SW Caribbean is supporting generally moderate easterly winds across the basin with 4-6 ft seas. Fresh to strong E-NE winds are observed over the Colombian Basin, where seas are 6-8 ft. For the forecast, the pressure gradient between a ridge N of the area and the Colombian low will support fresh to strong trades in the south-central Caribbean through tonight. Winds will gradually diminish to below normal basin-wide Tue through Wed night as an Atlantic cold front sinks southward toward the NE Caribbean islands. The cold front is forecast to reach the Greater Antilles on Thu. The front will bring large N swell through the NE Caribbean passages and Tropical N Atlantic waters beginning Thu and lasting into the weekend. ATLANTIC OCEAN... Please read the Special Features section for details on a gale warning and significant swell events impacting the Atlantic forecast waters this week. A cold front extends from 31N37W to 24N60W to 25N66W. Fresh to strong winds are within 90 nm east of the front N of 28N, and west of the front to 60W and N of 28N. Seas in the 12-16 ft range are over these waters and discussed in the special features section above. Gentle to moderate winds are elsewhere N of 24N as well as S of 10N, with light to gentle winds prevailing elsewhere. Seas are 8 ft or greater elsewhere N of 25N between 27W and 68W as well as from 14N to 25N between 20W and 41W. Seas of 2-4 ft are noted over the waters N of the Greater Antilles to 25N, with seas of 5-7 ft elsewhere over the discussion waters. For the forecast west of 55W, a cold front extends from 24N55W to 25N66W. The front will weaken tonight into early Tue as it moves SE. High pressure is building in east of Florida tonight. Large NW to N swell in the wake of the front will continue to affect the NE waters through Tue. A second cold front will enter the area late Tue, and reach from 30N55W to 26N70W to 28N81W by Wed morning. Gale force winds are expected on both sides of the front Tue night into Wed N of 28N and E of 70W. Behind the front, NW winds will remain fresh to strong through late week. A significant NW to N swell event will follow the front, with seas of 12 to 20 ft covering most of the waters N of 25N and E of 73W by early Wed afternoon. Swell up to 12 ft will reach as far south as 21N by early Thu. Looking ahead, the next cold front is forecast to move off the southeast U.S. coast by Fri night, brining strong winds to waters east of Florida. $$ Flynn