000 AXNT20 KNHC 250606 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 25 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... IAN... Tropical Storm Ian is centered near 14.7N 77.7W at 25/0300 UTC or 345 nm SE of Grand Cayman, and moving W at 11 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained winds are 45 kt with gusts to 55 kt, and seas are peaking at 8 to 10 ft near and just NE of the center. Scattered moderate to isolated strong convection is noted within 80 nm of the center. Ian is expected to gradually turn toward the NW Sun, then NNW on Mon with little change in forward speed. More rapid intensification is forecast, Ian should reach hurricane strengthen SW of Jamaica on Sun before passing W of the Cayman Islands Mon. Ian is forecast to become a major hurricane 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 over Jamaica, the Cayman Islands and western Cuba, which can cause flash flooding, and possible mudslides in areas of higher terrain. 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 49N60W at 25/0430 UTC and moving N at 20 kt. Estimated minimum central pressure is 963 mb. Maximum sustained winds are 40 kt with gusts to 55 kt. 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. 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 Tropical Cyclone Information Statement issued by Environment Canada at www.weather.gc.ca/hurricane/statements_e.html for more details. GASTON... Tropical Storm Gaston is centered near 38.6N 33.4W at 25/0300 UTC or 220 nm W of Faial Island in the central Azores, and moving W at 10 kt. Estimated minimum central pressure is 997 mb. Maximum sustained winds are 45 kt with gusts to 50 kt, and seas are peaking at 18 to 20 ft near and NE of the center. Gaston will continue to move west though Sun, then turns toward the WSW Mon. Tropical storm conditions will continue across the western Azores through Sun morning before improving Sun afternoon as Gaston moves away from the islands. Heavy rainfall over the western and central Azores should begin to diminish Sun afternoon. 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 22.9N 20.3W at 25/0300 UTC or 465 nm NNE of the Cabo Verde Islands, and moving N at 9 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained winds are 30 kt with gusts to 40 kt, and seas are peaking at 8 to 10 ft near and NE of the center. Scattered showers and thunderstorms are occurring N and NE of the center from 24N to 27N between 16W and 21W. A northward motion will continue over the next day or two before turning toward WNW. Hermine is expected to continue to weaken, and become a remnant low later Sun. 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 northeast of the Cabo Verde Islands at 18N21W through a 1009 mb low centered near 12N37W to 12N39W. An ITCZ then continues from 12N39W to 13N55W. Scattered moderate convection is noted near the low and monsoon trough from 10N to 16N between 31W and 39W, and also south of the ITCZ from 10N to 12N between 51W and 53W. Numerous moderate to isolated strong convection is flaring up southeast of the monsoon trough near the Guinea-Bissau/Guinea coast. The eastern end of the East Pacific monsoon trough is triggering isolated thunderstorms over Panama and adjacent Caribbean waters. ...GULF OF MEXICO... Please refer to the Special Features section above on Tropical Storm Ian, which is anticipated to impact the eastern Gulf in the middle of next week. A surface trough is producing isolated thunderstorms at the east- central Gulf. A 1016 mb high pressure is centered near the north-central Gulf, supporting light to gentle winds and seas of 1 to 2 ft. Gentle to moderate NE to ESE winds and 2 to 3 ft seas prevail for the rest of the Gulf. For the forecast, conditions will begin to deteriorate across the eastern and central Gulf of Mexico by Tue as Ian moves northward from Cuba as a major hurricane. Residents along the Florida west coast and Big Band area need to monitor this system closely and review your hurricane preparedness plan. ...CARIBBEAN SEA... Please refer to the Special Features section above on Tropical Storm (T.S.) Ian moving across the basin. Convergent easterly winds north of T.S. Ian are triggering scattered showers and isolated thunderstorms near Jamaica and south of Haiti. Convergent southerly winds are coupling with divergent flow aloft to generate numerous heavy showers and scattered thunderstorms over the south-central basin, including northern Colombia and northwestern Venezuela. Outside the main impacts of T.S. Ian across the central Caribbean, moderate to locally fresh E to SE winds with 3 to 6 ft seas are present across the eastern, north-central and south- central basin. Gentle to moderate NNE to NE winds and seas at 2 to 4 ft exist over the northwestern basin, while light to gentle winds and 1 to 3 ft seas prevail for the southwester basin. For the forecast, T.S. Ian will move to 15.3N 79.3W Sun morning, strengthen to a hurricane near 16.6N 81.0W Sun evening, then reach 18.3N 82.5W Mon morning. Hurricane Ian will be near 20.1N 83.7W Mon evening, 22.0N 84.5W Tue morning, and 23.9N 84.9W Tue evening. Ian will is forecast to intensify more rapidly as it moves across the northwestern basin Sun through Mon. Heavy rainfall and hazardous marine conditions will impact waters near Jamaica, the Cayman Islands, and Cuba. ...ATLANTIC OCEAN... Please refer to the Special Features section above on Post- tropical Cyclone Fiona, Tropical Storms Gaston and Tropical Depression Hermine in the Atlantic Basin. A weakening stationary front curves west-southwestward from east of Bermuda across 31N58W and the northwest Bahamas to southern Florida. Isolated thunderstorms are seen along and up to 40 nm along either side of the front. Convergent southerly winds farther south of the front are causing scattered showers and isolated thunderstorms from 24N to 26N between 60W and 71W. Convergent trades are creating scattered showers and thunderstorms from eastern Cuba to the southeast Bahamas. Refer to the Monsoon Trough/ITCZ section for additional weather in the basin. Outside the main influence of Tropical Depression Hermine, gentle to moderate ENE to SE winds and seas at 5 to 8 ft in northerly swell are present near and east of the stationary front, north of 25N between 44W and the Georgia-Florida coast. Moderate to fresh with locally strong NE to E winds and seas of 5 to 8 ft are found near the Canary Islands north of 24N between the Western Sahara coast and 27W. The Atlantic ridge is sustaining gentle to moderate ENE to E trades with 4 to 6 ft seas north of 15N between 27W and the 44W/Lesser Antilles. Light to gentle monsoonal and southerly winds and seas of 3 to 5 ft prevail for the remainder of the Atlantic Basin. For the forecast west of 55W, northerly swell N of 26N and W of 55W will gradually subside during the beginning of next week. Tropical Storm Ian is forecast to be a major hurricane at the eastern Gulf of Mexico Tue through Wed. Impacts from Ian may affect Atlantic waters offshore Florida after midweek. $$ Chan