000 AXNT20 KNHC 221757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Sep 22 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Ophelia is centered near 32.7N 76.0W at 22/1800 UTC or 130 nm SE of Cape Fear North Carolina, moving NNW at 10 kt. Estimated minimum central pressure is 992 mb. Max mum sustained wind speed is 50 kt with gusts to 60 kt. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Seas 12 ft or greater are occurring within 240 NM NE quadrant, 120 NM SE quadrant, 160 NM SW quadrant, and 180 NM NW quadrant with peak seas to 20 ft. Scattered moderate and isolated strong convection is noted within 180 NM in the N semicircle. A north to north- northwest motion is expected during the next couple of days. On the forecast track, the center of the low will approach the coast of North Carolina tonight, and then move across eastern North Carolina, southeastern Virginia, and the Delmarva Peninsula Saturday and Sunday. Some strengthening is forecast before landfall, and the low is expected to become a tropical storm before it reaches the coast of North Carolina. Regardless of whether it becomes a tropical storm, the system is expected to bring tropical storm conditions to portions of the southeast and mid-Atlantic coasts. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Sixteen NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Invest 90L in the Central Tropical Atlantic: The axis of a tropical wave is analyzed along 33W with a 1009 mb low centered at 14N33W. Maximum winds are currently 25 kt and peak seas are up to 9 ft. Scattered moderate convection is noted from 14N-20N between 28W-35W. Shower and thunderstorm activity associated with this area of low pressure continues to show signs of organization. Further development is expected, and a tropical depression is likely to form during the next couple of days while the system moves generally westward at 10 to 15 kt. The system is then expected to turn west-northwestward early next week as it moves over the central tropical Atlantic. The formation chance through 48 hours is high. Please see the latest Tropical Weather Outlook at www.hurricanes.gov for more information. ...TROPICAL WAVES... Please see the Special Features Section for details on the tropical wave (Invest 90L) along 33W. A central Atlantic tropical wave has its axis along 57W, south of 22N, moving westward around 10 kt. Scattered moderate convection is noted south of 12N west of 57W. ...MONSOON TROUGH/ITCZ... The monsoon trough reaches the Atlantic through the coast of Senegal near 14N16W and continues westward to the aforementioned low pressure near 14N33W, before terminating near 10N43W. The ITCZ then extends from 10N43W to 10N51W. Scattered moderate convection is noted from 14N-20N between 28W-35W. GULF OF MEXICO... Weak high pressure over the lower Mississippi Valley is supporting only light to gentle NE to E breezes and slight seas across most of the basin this afternoon. Isolated moderate convection is noted in the E Gulf between 24N-27N and east of 87W. For the forecast, the weak high pressure over the lower Mississippi Valley will control the weather pattern across basin through early next week. This will support mostly gentle to moderate east to southeast winds and slight seas, except for moderate to fresh winds pulsing offshore the western Yucatan Peninsula in the evenings. CARIBBEAN SEA... Weak surface ridging north of the Caribbean is forcing only gentle to moderate trades across the Caribbean, except fresh NE winds within 90 NM of the coast of Colombia. Seas are 4-6 ft in the central Caribbean and 2-4 ft in the W and E Caribbean. No deep convection is noted today over the Caribbean. For the forecast, the moderate to fresh trade winds in the central Caribbean will change little through the next few days as high pressure remains centered over the central Atlantic. Fresh to strong trade winds will pulse offshore of northern Colombia and northwest Venezuela during mainly the overnight and early morning hours into early next week. Looking ahead, combined seas will build northeast of the Leeward Islands starting Mon ahead of low pressure moving westward across the tropical Atlantic, possibly as the next tropical cyclone. ATLANTIC OCEAN... Please see the Special Features section section above for information on Tropical Storm Ophelia and Invest 90L. A trough extends from Tropical Storm Ophelia south-southwestward to 24N79W. Scattered moderate convection is noted from 21-25N between 68W-79W. Elsewhere, ridging extends across the Atlantic along roughly 30N. Between the ridge and the monsoon trough/ITCZ, the trades are gentle to moderate with seas 6-8 ft. Winds and seas are higher in the vicinity of Potential Tropical Cyclone Sixteen and Invest 90L. Isolated moderate convection is noted from 21N-26N between 47W-56W in association with an upper- level trough. For the forecast west of 55W, Ophelia will move to 33.2N 76.3W this evening, then continue to move north of the area and inland across coastal North Carolina early Sat. A weak ridge will build in the wake of Ophelia off northeast Florida through early next week, although a trough will persist across the Bahamas. Looking ahead, combined seas will build northeast of the Leeward Islands starting Mon ahead of low pressure moving westward across the tropical Atlantic, possibly as the next tropical cyclone. $$ Landsea