842 AXNT20 KNHC 242212 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Sep 24 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 1800 UTC surface analysis and satellite imagery through 2200 UTC. ...SPECIAL FEATURES... IAN... Tropical Storm Ian is centered near 14.3N 77.0W at 24/2100 UTC or 220 nm S of Kingston Jamaica moving W at 14 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt, with seas to 10 ft near the center. Numerous moderate to scattered strong convection is noted within 180 nm of the center of Ian. Ian is expected to continue to intensify as it moves westward through early Sun before turning more northward through Mon, reaching hurricane strength by early Mon west of Jamaica and south of Grand Cayman. Ian is forecast to become a major hurricane by early Tue as it approaches the western tip of Cuba, then continue into the eastern Gulf of Mexico through mid week. Ian is expected to produce heavy rainfall, flash flooding, and possible mudslides in areas of higher terrain, particularly over Jamaica and Cuba. Expect life-threatening storm surge and hurricane-force winds in portions of western Cuba beginning late Mon. Regardless of Ian’s exact track, there is a risk of dangerous storm surge, hurricane-force winds, and heavy rainfall along the west coast of Florida and the Florida Panhandle by the middle of next week, and residents in Florida should ensure they have their hurricane plan in place, follow any advice given by local officials, and closely monitor updates to the forecast. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. FIONA... Post-Tropical Cyclone Fiona is centered near 48.4N 60.5W at 24/2100 UTC or 70 nm NW of Port Aux Basques Newfoundland moving NE at 7 kt. Estimated minimum central pressure is 952 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. The storm has slowed down significantly, but a faster north to north- northeast motion is expected, taking the center of the system across Labrador tonight and early Sunday. Fiona is forecast to continue to affect portions of Atlantic Canada through early Sunday, and significant impacts from high winds, storm surge, and heavy rainfall are expected. Heavy rains from Fiona are expected to continue to impact portions of Atlantic Canada into Sunday. This rainfall is expected to produce flooding, some of which could be significant. Large swells generated by Fiona are expected to cause life-threatening surf and rip current conditions along the coast of the northeast United States, Bermuda, and Atlantic Canada during the next couple of days. Please read the latest High Seas Forecast issued by the Ocean Prediction Center at website https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. GASTON... Tropical Storm Gaston is centered near 38.2N 31.8W at 24/2100 UTC or 150 nm W of Faial Island In The Central Azores moving W at 10 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt, with very rough seas near the center. Gaston will continue to move west for a day or so, then move WSW. Tropical storm conditions over the western Azores should diminish overnight as Gaston moves away from the islands. Gaston is expected to produce heavy rainfall over the western and central Azores through early Saturday. This rainfall may result in landslides and areas of flooding. Please read the latest High Seas Forecast issued by the Ocean Prediction Center at website https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. HERMINE... Tropical Depression Hermine is centered near 21.8N 20.6W at 24/2100 UTC or 400 nm NNE of the Cabo Verde Islands moving N at 9 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt, with rough seas near and to the north of the center. Hermine remains strongly sheared with an exposed center to the southwest of scattered moderate to isolated strong convection. A northward motion will continue over the next day or two before a turn toward the left. Hermine is expected to continue to weaken, and become a remnant low in the next 24 hours. Please read the latest High Seas Forecast issued by Meteo-France at website http://weather/gmdss.org/ll.html and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... There are no tropical waves present based on the latest analysis. ...MONSOON TROUGH/ITCZ... A monsoon trough extends west-southwestward from near the Cabo Verde Islands at 18N21W through a 1009 mb low centered near 13N37W. An ITCZ then continues from 10N40W to 09N60W. Scattered moderate convection is noted within 90 nm in the NW semicircle of the low near 12N36W. ...GULF OF MEXICO... Please refer to the Special Features section above on Tropical Storm Ian, which is anticipated to impact the eastern Gulf the the middle of next week. 1016 mb high pressure is centered over the northwest Gulf, with weak troughing over the north-central and northeast Gulf. This pattern is maintaining generally light breezes and slight seas across the basin, No significant shower or thunderstorm activity is noted at this time. For the forecast, conditions will begin to deteriorate across the southeastern Gulf of Mexico by late Mon as the center of Ian emerges from western Cuba and the Yucatan Channel. Gulf coast residents and mariners over mainly the eastern Gulf should follow the latest advisories over the next several days on Ian and make preparations accordingly. ...CARIBBEAN SEA... Please refer to the Special Features section above on Tropical Storm Ian moving across the basin. Outside of the main impacts of T.S. Ian across the central Caribbean, no significant shower or thunderstorm activity is evident at this time. Moderate E to SE winds and slight to moderate seas are observed across the eastern Caribbean, and light to gentle NE breezes and slight seas are noted over the northeast Caribbean. For the forecast, Ian will move to 14.6N 78.4W Sun morning, 15.7N 80.3W Sun afternoon, strengthen to a hurricane near 17.4N 82.2W Mon morning, 19.2N 83.5W Mon afternoon, 20.9N 84.4W Tue morning, and 23.1N 85.0W Tue afternoon. Ian will change little in intensity as it moves near 26.2N 84.8W by Wed afternoon. Deteriorating marine conditions can be expected near the track of Ian, including the central Caribbean through early Sun, and portions of the northwest Caribbean later on Sun through Tue. Heavy rainfall and hazardous marine conditions will impact waters near Jamaica, the Cayman Islands and Cuba. Looking ahead, conditions will improve across the basin starting mid week. ...ATLANTIC OCEAN... Please refer to the Special Features section above on Post- tropical Cyclone Fiona and Tropical Storms Gaston and Hermine in the Atlantic Basin. A weak cold front extends from southeast of Bermuda near 31N60W to 27N72W, where it becomes stationary and extends across the northern Bahamas to near Jupiter Inlet, Florida. Earlier convection along this front has diminished. Buoy and altimeter satellite data indicate 8 to 10 ft seas mainly north of the front and west of 70W. This is northerly swell associated with the passage of Fiona across the western Atlantic. Elsewhere, outside of the main areas of impact associated with Hermine, mostly gentle to moderate trade winds and moderate seas are noted across the basin. For the forecast west of 55W, large swells from extratropical cyclone Fiona continue across the forecast waters north of 27N and west of 70W through late Sun, then subside. A ridge will build across the waters north of 27N through Tue, supporting moderate winds and seas farther south. Looking ahead, T.S. Ian, currently in the Caribbean Sea, is expected to intensify into a major hurricane and move into the eastern Gulf of Mexico next week. Marine conditions may deteriorate starting mid week off the east coast of Florida and across the northern Bahamas as a result. $$ Christensen