018 AXNT20 KNHC 212231 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Hurricane Nigel is centered near 43.7N 40.8W at 21/2100 UTC or 550 nm ESE of Cape Race Newfoundland, moving ENE at 32 kt. Estimated minimum central pressure is 977 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Peak seas are currently 43 ft. Numerous moderate convection is noted from 43N to 49N between 35W and 43W. This general motion to the ENE is expected to continue for the next 24 hours. Weakening is forecast during the next couple of days, and Nigel is forecast to become a post- tropical cyclone tonight or early Friday. Hazards associated with Nigel will remain well north of the TAFB forecast waters. Please read the latest HIGH SEAS FORECAST issued by the Ocean Prediction Center at website under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php. Please see the latest Nigel NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Potential Tropical Cyclone Sixteen is centered near 29.2N 75.9W at 21/2100 UTC or 300 nm SE of Charleston South Carolina, moving N at 7 kt. Estimated minimum central pressure is 1012 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous moderate isolated strong convection is from 25N to 31N between 72W and 75W. A general NNW to N motion is expected into the weekend. On the forecast track, the center of the cyclone is expected to approach the coast of North Carolina within the warning area late Fri into early Sat. Strengthening is expected before landfall, and the system is forecast to become a tropical storm offshore North Carolina late Fri. Regardless of whether the system become a tropical storm, the system is expected to bring tropical-storm conditions to portions of the southeast and mid-Atlantic coast. 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. Eastern Tropical Atlantic: Broad low pressure is developing in association with a eastern Atlantic tropical wave, centered near 13N30W. The wave and low are moving W at around 10 kt. Shower and thunderstorm activity in the vicinity of the low, a couple hundred miles SW of the Cabo Verde Islands, has shown some signs of organization this evening, with scattered moderate to isolated strong convection extending from 12N to 17N between 26W and 31W. Fresh to locally strong E winds and seas of 8 to 10 ft are present within about 100 nm N of the low's center. Environmental conditions are forecast to be conducive for gradual development of this system, and a tropical depression is likely to form this weekend or early next week while the system moves generally westward at 10 to 15 kt across the eastern and central tropical Atlantic. There is a MEDIUM chance of development through 48 hours. Please see the latest Tropical Weather Outlook at www.hurricanes.gov for more information. ...TROPICAL WAVES... A weak central Atlantic tropical wave previously along 38W has dissipated late today. A western Atlantic tropical wave has its axis along 56W, from 04N to 23N, moving westward at around 10 kt. Scattered moderate convection has developed where this wave is interacting with an upper level trough to the north, with some showers and thunderstorms noted from 16N to 21N between 51W and 56W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near 18N16W and continues to the aforementioned low pressure centered near 13N30W to 10N49W. Scattered moderate convection has developed from 04N to 07N between 21W and 26W and from 04N to 14N between 38W and 43W. GULF OF MEXICO... Weak high pressure centered to the NE is dominating the basin. There is a weak surface trough extending from near 29N86W to 25N84W that is inducing scattered moderate convection along and to the SE of it, continuing E to the Florida coast. Mainly gentle NE winds prevail across the Gulf, with seas of 1 to 3 ft. Some moderate winds are ongoing in the eastern Bay of Campeche, behind a surface trough that moved W off the coast of the Yucatan Peninsula this afternoon. For the forecast, high pressure will be in control of the weather pattern across the Gulf waters through most of the forecast period allowing for generally gentle to moderate east to southeast winds and slight seas, except pulsing to moderate to fresh offshore the western Yucatan Peninsula in the evenings due to local effects. CARIBBEAN SEA... Scattered moderate convection is located in the NE Caribbean just W of the Leeward Islands, otherwise relatively dry air is precluding showers and thunderstorms aside from diurnal activity over land areas. Fresh to locally strong winds are occurring offshore near the border of Colombia and Venezuela, otherwise mainly moderate trades prevail, except for light winds in the Lee of Cuba. Seas are 4 to 6 ft in the SW Caribbean, 1 to 3 ft in the NW Caribbean, and 2 to 4 ft elsewhere. For the forecast, moderate to fresh trade winds in the central Caribbean will change little through the next few days. Trade winds will pulse to fresh to strong speeds offshore northern Colombia and northwest Venezuela during the overnight and early morning hours into early next week. Elsewhere moderate or weaker winds will prevail with slight to moderate seas. ATLANTIC OCEAN... Please see the SPECIAL FEATURES section section above for information on Potential Tropical Cyclone Sixteen located N of the Bahamas and low pressure forming just E of the Cabo Verde Islands that has the potential for tropical development into the weekend. The stationary front extending NE from Potential Tropical Cyclone Sixteen is beginning to lift N as a warm front. This front extends from the system near 29N76W to 31N74W. The front that stretched SW from Sixteen has devolved into a surface trough, and this evening is located from around 29N74 into the northern Bahamas. Convection associated with all these features is described in the Special Features section above. Elsewhere across the tropical Atlantic, a weak surface trough from 30N55W to 26N59W is producing little in the way of sensible weather, otherwise high pressure, centered near 29N35W at 1020 mb, is dominating. Aside from areas influenced by the previously depicted special features, a band of moderate to locally fresh trades from 15N to 26N extends across the basin. To the north and south of these trades, winds are light to gentle. Seas basin-wide range from 4 to 7 ft. For the forecast W of 55W, Potential Tropical Cyclone Sixteen will move to 30.8N 75.8W Fri morning, and will be N of the forecast region near 32.6N 76.0W by Fri afternoon. In its wake, a ridge will build from E to W across the area through the upcoming weekend. $$ KONARIK