911 AXNT20 KNHC 071048 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Dec 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURE... Atlantic Ocean Gale Warning... A primary cold front curves southwestward from 31N61W to beyond the eastern tip of Cuba. Scattered moderate convection is seen within 120 nm east of this front, mainly north of 28N and east of 59W. A secondary cold front extends southwestward from near 31N64W to Andros Island, Bahamas. Near-gale to gale-force winds are occurring north of 28N between 52W and 67W. Fresh to strong winds are elsewhere north of 24N between 41W and 77W. An 07/0300 UTC satellite altimeter pass measured seas up to 18 ft near 30N63W. Currently, seas of 12 to 19 ft are likely occurring north of 26.5N between 52W and 75.5W, highest north of 28N between 58W and 71W. The fronts are expected to merge this afternoon while moving southeastward toward the central Atlantic. As a result, these winds and seas will shift eastward into the central Atlantic through this afternoon. As the combined front pulls farther eastward and weakens, conditions should begin to improve tonight. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more details. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near the Guinea-Bissau/Guinea border near 11N15W then extends southwestward to 06N18W. An ITCZ continues westward from 06N18W across 03N33W to 07N50W. Scattered moderate isolated strong convection is noted along and within 180 nm N of the ITCZ between 33W and 49W. ...GULF OF MEXICO... A 1028 mb high pressure centered over Alabama spreads ridging across the Gulf of Mexico. Some isolated showers are noted in the south-central portion of the basin. In the SE and south-central Gulf, winds are NE moderate to locally fresh, with 5 to 7 ft seas. Elsewhere, winds are gentle to moderate with 3 to 5 ft seas. For the forecast, moderate or weaker winds will prevail today. The high pressure over Alabama will shift eastward into the Atlantic tonight, inducing moderate to locally fresh return flow across most of the basin Fri through Sat. A strong cold front is forecast to enter the NW Gulf Sat evening. The front will reach from Cedar Key, Florida to Cancun, Mexico Sun evening, and exit the basin by Mon morning. Strong to near-gale force winds are expected behind the front, with gale force winds possible across the western Gulf, from offshore southern Texas southward to the Bay of Campeche Sat night through Sun evening. Strong NW gales near 45 kt are possible offshore Veracruz Sun afternoon. ...CARIBBEAN SEA... A cold front stretches west-southwestward from the eastern tip of Cuba across the Gulf of Honduras to southern Belize. Isolated showers are evident over the northwest Caribbean. Fresh to locally strong NE winds are north of the front, over the NW Caribbean, along with 5 to 7 ft seas. A trade-wind regime continues for the remainder of the basin with isolated showers noted in the SE Caribbean. Fresh to strong NE to ENE winds and 6 to 9 ft seas dominate the south-central basin, including the Gulf of Venezuela. Gentle to moderate NE to ESE winds and seas at 4 to 6 ft prevail in the eastern Caribbean. For the forecast, the cold front will reach from the N coast of Hispaniola to the Gulf of Honduras tonight, where it will remain nearly stationary through Fri night before dissipating Sat. Fresh to strong NE winds N of the front across the northwest Caribbean will diminish slightly late today. However, strong winds will develop in the Windward Passage this afternoon with the front and expand across most of the east and central Caribbean, lasting from tonight through Sun. By late Sun, the majority of these winds are expected to be over the central Caribbean. Looking ahead, the next cold front could enter the northwest Caribbean by early next week. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section at the beginning about an ongoing Gale Warning, which covers the weather from 24N to 31N between 40W and 81W. Fresh N winds extend across the Bahamas to Cuba. Seas of 8 to 10 ft are reaching the northern Bahamas on the Atlantic side. A narrow surface ridge, with comparatively lighter winds and lower seas, extends from 1021 mb high pressure near 31N24W to 1021 mb high pressure near 27N39W to 21N55W to the Dominican Republic. To the south, fresh trade winds and 6 to 9 ft seas prevail from 04N to 18N between 30W and 60W. For the forecast W of 55W, a cold front extends from near 31N61W to the eastern tip of Cuba. A secondary cold front trails it, extending from 31N64W to Andros Island, Bahamas. The secondary front will speed up and merge with the first front by late today. The main front will reach from near 25N55W to the N coast of Hispaniola this evening. Gale force winds and high seas are expected both ahead of and behind this front, to the north of 28N through late this afternoon. The gale winds will shift east of 60W by this afternoon. The front will stall and weaken along 20N Fri through Sat as strong high pressure builds across the western Atlantic. The gradient between the strong high pressure along 31N and lower pressure associated with the stalled front will induce fresh to strong ENE trade winds south of 23N Fri through Sun. On Sun, the front will dissipate as fresh to strong southerly flow sets up over the waters east of northeast Florida to 69W in advance of the next cold front. This cold front is expected to move into the NW forecast waters late Sun, followed by fresh to strong northwest winds. Seas will build both east and west of this cold front. $$ Hagen