000 AXNT20 KNHC 080409 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Mar 8 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 0400 UTC. ...SPECIAL FEATURES... Atlantic Ocean Gale-Force Wind Warning: A cold front is currently crossing into the discussion area south of 31N in the western Atlantic. As of 0200 UTC scatterometer data confirmed pre-frontal SW winds have increased to gale force north of 29N, between 57W and 66W. The front extends from a storm force 985 mb low pressure center near 37N58W to 31N70W to a much weaker 1011 mb low near 33N78W. The front is progressing quickly southeastward and will extend from 31N53W to 26N70W by Wed morning. As the front progresses, post-frontal NW winds will also reach gale force. Winds are expected to remain above gale force through Thu, especially ahead of the front. This prolonged event will build seas in the basin already impacted by elevated swell from previous storms, creating some of the highest sea states in the subtropical Atlantic this year. Seas are currently in the 12-16 ft range north of 28N, between 40W and 68W. Seas will quickly build to 20 ft by Wed morning while propagating south and east. Seas in excess of 12ft will reach as far south as 21N by Thu morning. By late Thursday, the vast majority of west and central Atlantic east of the Bahamas and north of 17N will be impacted by rough seas in excess of 8 ft while very rough to high seas persist in the subtropical central Atlantic. The swell from this event will slowly subside from Fri-Sun, although the next significant low-pressure system will partially rebuild swell in the western Atlantic over the weekend. 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 coastal border of Liberia and Sierra Leone near 07N11W to 04N17W. The ITCZ continues from 04N17W to 01S44W. Scattered moderate convection is observed east of 40W from the equator to 04N. GULF OF MEXICO... High pressure prevails across the Gulf of Mexico. Gentle to moderate winds are noted over the western and southern Gulf with light to gentle winds elsewhere. Seas are in the 2-4 ft range over the western and southern Gulf and 1-2 ft over the NE Gulf. 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 Havana, Cuba to near Mobile, Alabama on Thu morning, before dissipating by Thu night. Moderate to fresh SE winds are forecast in the far E Gulf, east of the front. Another cold front is likely to reach the northern Gulf Coast Fri and move over the northern Gulf waters by Fri night before dissipating Sat. CARIBBEAN SEA... Fresh to strong winds prevail over the south central Caribbean. Gentle to moderate winds are noted elsewhere. Seas are in the 4- 7 ft range over the south central Caribbean, including offshore Colon, Panama. Seas are generally 2-4 ft across the remainder of the basin. For the forecast, gentle to locally moderate winds will prevail across most of the basin tonight and Wed due to a weak pressure gradient as an Atlantic cold front sinks southward toward the Caribbean islands. The cold front is forecast to reach the Greater Antilles on Thu, then reach from the Leeward Islands to Jamaica to the western tip of Cuba early Fri before dissipating Fri night. The front will bring large N swell through the NE Caribbean passages and Tropical N Atlantic waters beginning Thu and lasting into the weekend. Also, fresh N to NE winds are expected behind the front over the far N Caribbean. ATLANTIC OCEAN... Please read the Special Features section for details on a gale warning and associated high seas across the Atlantic forecast waters this week. In the eastern Atlantic, a weak cold front extends from 31N29W to 22N53W, with the tail end gradually dissipating. Scattered moderate convection is within 60 nm of the front N of 27N. Fresh winds and rough seas noted are on both sides of the front and a recent altimeter pass found 12-15 ft swell in the central Atlantic north of 27N. Otherwise a high-pressure ridge extends from the Canary Islands to the Caribbean. Winds are light to gentle near the ridge axis. Swell in excess of 6 ft prevails across the basin. For the forecast W of 55W, westerly winds are increasing across the waters N of 28N as a cold front enters the area this evening. The front will reach from 30N55W to the NW Bahamas to central Florida by Wed morning, and from 23N55W to the N coast of Hispaniola to central Cuba by Thu morning. Gale force are expected on either side of the front tonight, mainly N of 28N between 55W and 70W. Winds are forecast to diminish below gale force over the NE waters by late Wed afternoon, but strong NW winds will persist N of 27N and E of 65W through Fri. A significant NW to N swell event will follow the front, with seas of 12 to 21 ft covering most of the waters N of 25N and E of 74W by early Wed afternoon. Seas of 12 ft will reach as far south as 21N Thu morning. Looking ahead, the next cold front is forecast to move off the southeast U.S. by Fri afternoon, brining strong to near gale force winds to waters east of Florida. This system will move eastward across the area during the weekend. $$ Flynn