715 AXNT20 KNHC 151744 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Dec 15 2022 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning: A large and powerful low pressure system north of the area will bring strong to near gale force W to NW winds and very large seas through tonight to the waters east of 60W and north of 27N. Winds are forecast to reach gale force this evening for the area N of 30N between 49W and 54W with building seas to 23 ft. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic tropical waters through the coast of Sierra Leone near 08N13W to 07N15W. The ITCZ continues from 05715W to 02.5N30W to 03N49W. Scattered moderate convection is observed from 08N southward between 21W and 48W. GULF OF MEXICO... A cold front extends southwestward from the Florida Panhandle to near Veracruz, Mexico. A line of strong to severe thunderstorms is observed ahead of the front north of 24N between the frontal boundary and the west coast of Florida. Gusts will likely exceed 35 kts in the strongest thunderstorms. Fresh to strong SW winds are elsewhere in the northeast Gulf ahead of the front north of 25N. An area of fresh NW to N winds are observed across the Veracruz offshore waters. Otherwise, moderate to fresh NE winds are across the remainder basin either side of the frontal boundary. Seas behind the front are generally 5 to 8 ft, with up to 9 ft locally in the northeastern Gulf. Ahead of the front, seas range from 4 to 8 ft north of 23N and 2 to 4 ft south of 23N in the southwestern Gulf. For the forecast, the cold front extending from the Florida panhandle to near Veracruz, Mexico will reach from SW Florida to the central Bay of Campeche while weakening. The line of strong to severe thunderstorms ahead of the front will continue to race eastward across the NE Gulf today. Fresh to strong NW to N winds west of the front and fresh to strong S winds ahead of the front in the NE Gulf will diminish later today. A new cold front will form over the W Gulf on Sat morning. The pressure gradient between the front and high pressure over the S United States is likely to induce a large area of strong to near gale N to NE winds over the N Gulf this weekend. The front should become stationary late Sun, and then transition to a warm front while it lifts northward to the NW Gulf by late Mon. CARIBBEAN SEA... Mainly strong trade winds are over the central Caribbean with seas in the 5 to 8 ft range. Moderate to fresh winds prevail elsewhere with 3 to 5 ft seas, with the exception of 6 to 7 ft in the NE Caribbean passages due to NE swell from the Atlantic. Only notable convection is found within 100 nm from the western Panama coast associated with the Pacific monsoon trough that extends into the basin. For the forecast, surface ridging north of the region will maintain fresh to strong NE to E tradewinds across the central and SW Caribbean Sea through Mon night, with moderate to locally fresh winds elsewhere. Large, long-period N to NE swell will continue to propagate through the Mona and Anegada Passages and affect the Tropical N Atlantic waters through Fri. Another large set of N swell is forecast to begin propagating through the Tropical N Atlantic waters starting late on Fri and continue through Mon night. ATLANTIC OCEAN... See the Special Features section above for details on a Gale Warning in the central Atlantic. Fresh to strong S to SW winds are offshore northeast Florida to roughly 75W this morning ahead of a strong cold front approaching the southeast U.S. coast.Scattered showers and thunderstorms are observed in this region north of 28N between the northeast coast of Florida and 78W. Farther east, a cold front extends from 31N57W to 26.5N64W, with a surface trough ahead of it analyzed from 31N49W to 23N63W. A recent scatterometer pass reveals fresh to strong W to NW winds behind the front affecting the waters N of 29N between 56W and 65W, while fresh to strong SW winds are noted ahead of the front and north of the surface trough, encompassing the area N of 27N between 50W and 60W. Seas are in the 8-11 ft range north of 20N, with seas of 12 to 14 ft near the strongest winds north of 29N between 51W and 63W. The remainder of the Atlantic subtropical waters is dominated by surface ridging, along with moderate to fresh NE winds and seas of 5 to 8 ft in N swell stretching across the basin south of 20N. For the forecast west of 55W, large and powerful low pressure system north of the area will bring strong to near gale force W to NW winds and very large seas through tonight to the waters east of 60W and north of 27N. The aforementioned front will move off the coast this evening, reaching from near 31N62W to the Florida Keys Sat morning, and merge with a reinforcing cold front Sun afternoon. This next cold front will extend from 30N70W to Florida Keys Sun morning and move eastward to 31N60W to the SE Bahamas Mon morning. Fresh to strong SE winds will proceed the front north of 27N. Large to very large, long- period N to NE swell will continue to affect much of the area for the next several days. $$ Nepaul