715 AXNT20 KNHC 220601 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0555 UTC. ...SPECIAL FEATURES... Hurricane Nigel is near 45.1N 36.7W at 11 PM EDT, and is moving east-northeast at 32 kt. Maximum sustained winds are 65 kt with gusts to 80 kt, and the minimum central pressure is 979 mb. Peak seas are currently 42 ft. Numerous moderate to strong convection is noted to the east of the center. A general NNE motion is expected to continue for the next day or so. A slower northward or north-northwestward motion is expected this weekend. 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 near 29.5N 75.3W at 11 PM EDT, and is moving north-northeast at 3 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1007 mb. Numerous moderate isolated strong convection is from 22N to 31N between 66W and 73W. Fresh to near gale force winds are found north of 27N and west of 70W. Peak seas are currently 13 ft. A faster northward or north- northwestward motion is expected later this morning through Sunday. On the forecast track, the center of the low will approach the coast of North Carolina through tonight, and then move across eastern North Carolina, southeastern Virginia, and the Delmarva Peninsula Saturday and Sunday. Additional strengthening is forecast during the next day or so, 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 eastern Tropical Atlantic: The axis of a tropical wave is analyzed along 30W. A 1009 mb low pressure system is near 13N along the wave axis. The disturbance is moving westward at 10-15 kt. Showers and thunderstorms continue to show signs of organization, from 11N to 18N and between 27W and 36W. Fresh to strong winds and seas of 7-10 ft are occurring in the northern semicircle of the low pressure. 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 mph 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... Please see the SPECIAL SECTION for details on the tropical wave (Invest 90L) along 30W. A central Atlantic tropical wave has its axis along 55W, south of 21N, moving westward at 10-15 kt. A few showers are noted near the norther portion of the wave axis. ...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 13.5N30.5W and then to 11N50W. A few showers are evident on satellite imagery from 05N to 13N and between 37W and 46W. GULF OF MEXICO... A weak high pressure pattern persists across the Gulf of Mexico. Isolated showers and thunderstorms are found in the Florida Straits, while a few thunderstorms are moving into the eastern Bay of Campeche. The remainder of the Gulf experiences fairly tranquil weather conditions. Moderate to locally fresh NE winds and seas of 2-4 ft are present south of 23N and east of 95W. Moderate or weaker winds and seas of 1-3 ft prevail elsewhere. 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... A few showers are seen on satellite imagery between Cuba and the Cayman Islands. Similar activity is present in the Gulf of Gonave. No deep convection is affecting the remainder of the Caribbean Sea. The pressure gradient between the 1023 mb subtropical ridge in the central Atlantic and lower pressures in northern South America support fresh to locally strong easterly winds in the south-central Caribbean, along with seas of 4-6 ft. Moderate or weaker winds and seas of 2-4 ft prevail the rest of the basin. For the forecast, moderate to fresh trade winds in the central Caribbean will change little through the next few days. 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. 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 and Invest 90L. An upper level low near 21N52W and plenty of tropical moisture are sustaining scattered moderate convection from 20N to 26N and between 45W and 55W. A recent scatterometer satellite pass captured moderate to fresh easterly winds in the area described. Seas in these waters are 6-8 ft. The remainder of the tropical Atlantic is dominated by a broad subtropical ridge, suppressing the development of deep convection. Moderate to locally fresh NE winds are also noted in the eastern Atlantic, from 19N to 27N and east of 27W. Seas in this region are 5-7 ft. Elsewhere, moderate or weaker winds and moderate seas prevail. For the forecast W of 55W, Potential Tropical Cyclone Sixteen is near 29.6N 75.3W at 11 PM EDT, and is moving north-northeast at 6 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1007 mb. Sixteen will move to 31.2N 75.5W Fri morning, then continue to move north of the area to the coast of North Carolina through early Sat. A weak ridge will build in the wake of Sixteen 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 by Tue ahead of low pressure moving westward across the tropical Atlantic, possibly as the next tropical cyclone. $$ DELGADO