000 AXNT20 KNHC 251002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... IAN... Tropical Storm Ian is centered near 14.9N 78.8W at 25/0900 UTC or 300 nm SSE of Grand Cayman moving WNW at 10 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt, and seas are peaking near 12 ft near in just N of the center. Numerous moderate to scattered strong convection is noted within 90 nm of the center. Ian is forecast to turn NW later today, NNW Mon, then N Tue. Rapid strengthening is forecast to begin later today and Ian is expected to become a hurricane later today or tonight, and reach major hurricane strength by late Mon or Mon night before it reaches western Cuba. Ian is expected to produce heavy rainfall over Jamaica, the Cayman Islands and western Cuba, which may produce 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. GASTON... Tropical Storm Gaston is centered near 39.0N 34.5W at 25/0900 UTC or 270 nm W of Faial Island In The Central Azores moving WNW at 9 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt, and seas are peaking at 18 to 20 ft near and NE of the center. Gaston is expected to return to a westward motion later today, then turn WSW Mon. Tropical storm conditions will continue across the western Azores this 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... Post-Tropical Cyclone Hermine is centered near 23.6N 20.2W at 25/0900 UTC or 500 nm NNE of the Cabo Verde Islands moving N at 6 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt, and seas are peaking at 8 to 10 ft near and NE of the center. Scattered moderate convection is noted N and NE of the center from 24N to 27N between 16W and 21W. A northward motion will continue today, with a NW turn Mon, then NNW Mon night. Hermine should dissipate within a couple of days. 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 14N36W. An ITCZ then continues from 13N37W to 14N57W. Numerous moderate to isolated strong convection is noted SE of the monsoon trough from 05N to 15N E of 25W. 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. 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 central eastern Gulf by the middle of the week. A 1016 mb high pressure is centered in the NW 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 Florida Panhandle 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 Ian moving across the basin. Also, refer to the monsoon trough section above for details on convection in the far SW basin. The remainder of the area is void of precipitation. 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 southwestern basin. For the forecast, Tropical Storm Ian is near 14.9N 78.8W 1002 mb at 5 AM EDT moving WNW at 10 kt. Maximum sustained winds are 45 kt with gusts to 55 kt. Ian will move to 15.7N 80.0W this afternoon, strengthen to a hurricane near 17.3N 81.7W Mon morning, and reach 19.1N 83.1W Mon afternoon. Hurricane Ian will be near 21.0N 84.1W Tue morning, 23.0N 84.6W Tue afternoon, and 24.8N 84.8W Wed morning. Ian will change little in intensity as it moves through the northeast Gulf of Mexico early Thu. Hazardous conditions will prevail in the NW Caribbean through Tue, before winds and seas gradually subside as Ian moves N of the basin. ...ATLANTIC OCEAN... Please refer to the Special Features section above for details on Tropical Storm Gaston and Post-Tropical Cyclone Hermine. A weakening stationary front curves west-southwestward from east of Bermuda across 31N58W and the northwest Bahamas to southern Florida. Convection previously along and ahead of this front has generally dissipated S of 31N. Convergent trades are creating scattered showers and thunderstorms from eastern Cuba to the southeast Bahamas. Refer to the Monsoon Trough/ITCZ section for additional convection in the basin. Outside the main influence of 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 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 midweek. $$ KONARIK