000 AXNT20 KNHC 140915 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Sep 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 0600 UTC surface analysis and satellite imagery through 0800 UTC. Discussion updated at 0700 UTC to account for the increased tropical cyclone development potential described in the special features section. ...SPECIAL FEATURES... Central Tropical Atlantic: A strong tropical wave extends along 48W/49W from 04N to 21N, moving west at 12 kt. A 1010 mb low pressure center is analyzed near 16N48W along this wave. Numerous moderate convection is observed from 13N to 20N between 44W and 50W. Fresh to strong easterly winds and 8-11 ft seas are observed along the northern half of this wave. Although environmental conditions are only marginally conductive, some additional development of this system is possible and a tropical depression could form during the next couple of days. This system is expected to move westward to west- northwestward over the tropical Atlantic and it is expected to be near the Leeward Islands on Friday. The current outlook assigns a medium chance of development through 48 hours and a medium chance through 5 days. Refer to the Tropical Weather Outlook issued by the NHC at: www.nhc.noaa.gov/?atlc for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave extends along 28W, just west of the Cabo Verde Islands, from 04N to 21N, moving west at around 10 kt. Scattered moderate and isolated strong convection is observed from 09N to 16N, between 27W and 31W. Moderate to fresh winds and seas of 6-8 ft are found mainly around the northern half of the tropical wave. A Caribbean tropical wave extends along 75W, from over Colombia near 04N to eastern Cuba at 21N, moving west at around 10 kt. Scattered weak convection is observed through the Windward Passage, southeast of Jamaica, and from 07N to 13N between 71W and 77W including over portions of northern Colombia and NW Venezuela. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Mauritania near 18N16W to 07N39W. In addition to convection associated with tropical waves, scattered moderate and isolated strong convection is observed from 05N to 10N, between 32W and 40W. ...GULF OF MEXICO... A weak cold front extends from just south of Apalachee Bay, Florida to 28N88W, continuing as stationary to just south of Galveston Bay, Texas. Upper-level divergent flow south of the boundary is supporting scattered showers and thunderstorms across the Gulf, south of 28N. Otherwise, a weak pressure gradient is supporting gentle to moderate winds and 1-3 ft seas across the basin. For the forecast, the weak front will completely stall again by late today before dissipating. Later in the week, high pressure will build over the southeast U.S. following the front, maintaining gentle to moderate easterly breezes and slight seas into the weekend. ...CARIBBEAN SEA... An upper-level low near Turks and Caicos is supporting scattered moderate convection in the Caribbean between 77W and 85W. Otherwise, a weak pressure gradient between subtropical high pressure and lower pressure over the SW Caribbean is supporting moderate to fresh easterly trade winds across the central and eastern Caribbean, as well as offshore Honduras. Gentle to moderate trades are elsewhere across the NW Caribbean, with light to gentle winds in the SW Caribbean south of 11N. Seas are 3-5 ft in the central and eastern Caribbean, and 1-3 ft in the NW Caribbean, except 3 to 5 ft offshore Honduras. Slightly higher seas are also noted through Atlantic passages in decaying N-NE swell. For the forecast, gentle to moderate winds, locally fresh, and slight to moderate seas will persist over the Caribbean today as a tropical wave moves from the central to western Caribbean. Winds and seas will increase somewhat from east to west starting tonight over the central Caribbean as high pressure builds north of the area in the wake of the tropical wave. Northerly swell moving through the Atlantic passages will gradually subside through tonight. Another tropical wave will into the eastern Caribbean Fri, and reach the central Caribbean by Sat, and then the western Caribbean late Sun into early next week. ...ATLANTIC OCEAN... A broad upper-level low over the Turks and Caicos is inducing scattered showers and thunderstorms across the Bahamas and surrounding waters in the western Atlantic, along with the northern portion of a tropical wave near eastern Cuba. A surface trough is in the region too, extending from 29N67W to near the central Bahamas at 25N78W. A high pressure centered southeast of Bermuda near 31N61W is supporting gentle to moderate anticyclonic flow with 5-7 ft seas, comprised primarily of northerly swell, across the waters north of 23N. A weak cold front extends across the central Atlantic from north of 31N42W to 27N50W where it stalls. Scattered thunderstorms are observed north of 29N within 75 nm along and east of the front. Gentle to moderate westerlies are observed behind this feature, with moderate SE winds ahead. Seas are generally 6-9 ft in the region, with stronger winds and higher seas near the tropical wave described above. Elsewhere in the tropical Atlantic, gentle to moderate winds and 5-7 ft seas dominate. For the forecast west of 55W, moderate northerly swell east of the Bahamas is expected to subside through today, mainly west of 65W. The northern end of a tropical wave will pass 55W south of 22N by early Fri, bringing at least fresh to strong E winds and locally rough seas to the area northeast of the northern Leeward Islands. The wave may weaken as it continues westward toward the Turks and Caicos Islands and southern Bahamas through Sat. Looking ahead, a cold front may move into the waters off northeast Florida and stall by the end of the week into the weekend. $$ Lewitsky