000 AXNT20 KNHC 150539 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Dec 14 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning: A large and powerful low pressure system centered north of the area will bring strong to near gale force W winds tonight through Thu night to the waters east of 65W and north of 27N. Very large seas can be expected in this area. By Thu night, the forecast calls for W to NW winds of 30- 35 kt N of 30N between 47W and 54W with seas of 17-24 ft in NW swell. 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 passes through the coast of Sierra Leone near 09N13W to 07N18W. The ITCZ continues from 07N18W to 04N35W to 03N50W. Scattered moderate convection is noted north of the ITCZ from 04N to 07N between 36W and 46W. GULF OF MEXICO... As of 0300 UTC, a cold front enters the Gulf of Mexico near Mobile Bay, AL, and extends SW to 25N92W and to the offshore waters south of Tampico, Mexico. A squall line is about 40 nm ahead of the cold front bringing severe weather to the coastal waters of Alabama and the Florida panhandle tonight. Gusts will likely exceed 35 kts in the strongest thunderstorms. Recent observations indicate strong NW winds behind the front, where seas have built to 10 ft. Ahead of the front, winds have increased to near gale southerly winds, and seas have built to 6 to 9 ft. Elsewhere, gentle to moderate winds are over the far NW and SW, as well as in the FL Straits. For the forecast, the cold front will reach from Apalachicola, FL to the central Bay of Campeche early Thu and from near Sarasota, FL to the central Bay of Campeche Thu night before slowing down and weakening. A line of strong to severe thunderstorms just out ahead of the front will race E across the north-central and NE Gulf tonight through Thu. Fresh to strong NW to N winds west of the front will diminish to moderate to fresh speeds overnight into Thu for the central and eastern Gulf. Fresh to strong southerly winds ahead of the front will diminish Thu as the front approaches Fl. The front should become stationary Fri night from the Straits of Florida to the south-central Gulf of Mexico before weakening further and should remain in about the same position through Sat as a surface trough forms over the SW Gulf. The gradient between this surface trough and high pressure over the southern U.S. is likely to induce a large area of fresh to strong N to NE winds over the central Gulf this weekend. The trough will transition to a warm front on Sun and lift northward to the NW Gulf by late Mon. CARIBBEAN SEA... Satellite derived wind data provided observations of fresh to strong trade winds over the south-central Caribbean, mainly south of 16N between 68W and 78W, where seas are up to 7 ft. Moderate to fresh winds prevail elsewhere with 3 to 5 ft seas except up to 6-7 ft in the NE Caribbean passages due to NE swell from the Atlantic. For the forecast, high pressure over the western Atlantic will maintain fresh to strong trade winds across the central Caribbean Sea through Fri, with moderate to fresh winds elsewhere. Large long-period N to NE swell will continue to propagate through the NE Caribbean passages and affect the Tropical N Atlantic waters through Fri. Another large set of N swell is forecast to propagate 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. A stationary boundary stretches from the central subtropical Atlantic near 31N46W and continues SW to near 25N60W, then dissipates to the southern Bahamas as high pressure is building in. No significant convection is associated with this boundary. Satellite derived wind data provided observations of gentle W flow behind the boundary to 30N. An area of moderate to fresh SW winds is noted from 27N to 31N between 36W and 50W. Seas surrounding the front are still generally 8 to 11 ft. A 1021 mb high pressure center in the W Atlantic is supporting light to gentle anticyclonic flow east of 75W and moderate to fresh SE winds west of 75W. Seas remain up to 6 to 9 ft in NE swell. Elsewhere, a diffluent pattern aloft is helping to induce convection from 20N to 30N between 45W and 50W. High pressure, near 30N28W dominates the eastern Atlantic and is supporting gentle to moderate east winds mainly south of 25N to 20N, and W-SW winds north of 25N. The pressure radiant between this higher pressure and lower pressure near the ITCZ is generating moderate to fresh trades across the Atlantic, mainly south of 20N. A dissipating frontal boundary is producing strong to near gale force SW-W winds and rough or very rough seas near the coast of Morocco. For the forecast west of 55W, large long-period N to NE swell will continue to affect much of the area for the next couple of days. A large and powerful low pressure system north of the area will bring strong to near gale force W winds and very large seas tonight through Thu night to the waters E of 65W and north of 27N. Fresh to strong southerly winds are offshore NE Florida associated with a strong cold front that approaches the SE U.S. coast. The front will move off the coast Thu afternoon, reach from near 31N65W tothe Florida Keys early Sat, and merge with a reinforcing cold front on Sun. The merged front is forecast to reach from near 29N55W to 26N66W and then stall to the central Bahamas by late Mon. Fresh to strong southerly winds will shift eastward across the northern and central waters through Sat and exit the area late Sat. Fresh northwest to north winds will follow behind the merged front. $$ Mora