000 AXNT20 KNHC 091705 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Dec 9 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 1700 UTC. ...SPECIAL FEATURES... Central Atlantic Gale Warning: A deepening 968 mb non-tropical low pressure system is located near 34.5N40.5W. An area of scattered moderate convection is observed north of 18N, between 20W and 46W. A very large area of gale force winds are observed in this mornings scatterometer pass north of 22N between 33W and 43W. Very rough to high seas cover an extensive area north of 15N, between 27W and 70W. Conditions will gradually improve today in the subtropical Atlantic as the low moves quickly NE. However, seas will remain very rough north of 25N through the weekend. Large, long-period N to NE swell will impact the Atlantic waters and Caribbean Passages between the southeastern Bahamas and the E Caribbean producing high seas into the start of next week, with large E swell reaching the Florida offshore waters N of 26N early Fri through Sat. Central Atlantic Gale Warning: A new low will develop along 65W and N of 31N by late Sat and move SSE entering the central Atlantic this weekend. Gale-force winds will develop near the low along 28N. These conditions will dissipate by early next week as the low moves quickly E while weakening. More information about these systems, including the associated Storm and Gale Warnings, can be found in the High Seas Forecasts issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic waters from the coast of Guinea near 11N15W and extends to 08N17W. The ITCZ continues from 08N17W to 03N46W. Scattered showers are noted along the ITCZ from 01N to 08N between 34W and 43W. ...GULF OF MEXICO... A surface trough is analyzed in the southwest Gulf from 23N91W to 19N94W. Weak convection is observed on satellite west of the trough, south of 20N to near Veracruz, Mexico. Across the remainder of the basin, a 1021 mb surface high centered near 28N91W is supporting generally fair weather conditions and mainly gentle to moderate easterly winds. Seas remain 1 to 4 ft over the majority of the basin, with 3 to 5 ft seas S of 25N including the Yucatan Channel. For the forecast, the 1021 mb high will meander through the weekend, then shift eastward early next week as a cold front approaches the NW Gulf. Gentle to moderate winds will prevail through the weekend, increasing to moderate to fresh early next week. Winds may increase to strong speeds and seas build up to 8 ft late Tue in the NW Gulf as the aforementioned front approaches from the NW. ...CARIBBEAN SEA... The pressure gradient between subtropical high pressure in the western Atlantic and lower pressure over Colombia is generating moderate to fresh NE winds west of 70W in Caribbean, including the Windward Passage, where seas are in the 6 to 8 ft range. A recent scatterometer pass reveals locally strong NE winds off NW Colombia. In the E Caribbean, gentle to moderate N winds prevail with mainly 4 to 6 ft seas. Seas are 8 to 12 ft near and SW of Atlantic passages due to long period NE swell originating from the gale force low in the central Atlantic. For the forecast, the strengthening non-tropical low pressure system in the central Atlantic is accelerating northward and gradually moving away from the forecast area. Large NE swell across the central Atlantic will move through the Caribbean Passages and Tropical Atlantic waters through late Sat, decreasing on Sun and increasing again early next week as another swell event reaches the region. High pressure over the Gulf of Mexico extends southeastward, sustaining NE-E winds across much of the forecast waters. Fresh to strong pulsing NE-E winds will occur in offshore Colombia into early next week. Moderate to fresh NE winds, occasionally pulsing to strong speeds, will affect the Caribbean Passages and the lees of the Greater Antilles through tonight. ...ATLANTIC OCEAN... Please read the Special Features section above for details on the Gale Warnings active in the basin. Elsewhere, a weak cold front extends across the western Atlantic from 31N64W to 29N70W to 31N75W. No notable convection is associated with this front. South of the front, a weak high pressure ridge off NE Florida is supporting gentle winds and 4-6 ft seas in the far western Atlantic. In the far eastern Atlantic, gentle to moderate anticyclonic flow with seas of 5 to 7 feet prevail. Otherwise, the remainder of the basin moderate or weaker winds and moderate seas prevail. For the forecast W of 55W, the deepening low pressure system over the central Atlantic is accelerating northward into the north Atlantic and forecast to strengthen into a powerful non-tropical cyclone. Large long-period north to northeast swell will impact the Atlantic waters and Caribbean Passages between the southeastern Bahamas and the E Caribbean, producing high seas into the start of next week, with large E swell reaching the Florida offshore waters N of 26N through Sat. A new low will develop along 65W and N of 31N by late Sat and move SE entering the central Atlantic this weekend. Gale-force winds will develop along 28N. These conditions will dissipate by early next week as the low moves quickly E while weakening. $$ Nepaul