000 AXNT20 KNHC 281212 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Sep 28 2022...Updated 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 1000 UTC. Updated at 1210 UTC For Hurricane Ian Special Feature ...SPECIAL FEATURES... Hurricane Ian is centered near 26.0N 82.7W at 28/1200 UTC or 50 nm W of Naples Florida, moving NNE at 9 kt. Minimum central pressure is 937 mb. Maximum sustained wind speed has increased to 135 kt with gusts to 165 kt. Ian is a strong category 4 hurricane. Hurricane force winds extend out 35 nm from the center. Tropical storm force winds extend out 120 nm NE quadrant, 130 nm SE quadrant, 100 nm SW quadrant and 150 nm NW quadrant. To the north and west of the main area of tropical storm force winds, strong NE winds near the coast from the Florida Panhandle to SE Louisiana have prompted Gale Warnings where frequent gusts to gale force are occurring and expected to continue. Seas of 12 ft or greater extend out 120 nm E semicircle, 270 nm SW quadrant and 210 nm NW quadrant. Peak seas are 29 ft. Numerous strong convection extends from 23N to 28N between 80W and 85W. Numerous moderate to isolated strong convection in banding extends from 23N to 31N between 75.5W and 80W. Ian is expected to cause a catastrophic storm surge, winds and flooding over portions of the Florida Peninsula later today. 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. Showers and thunderstorms associated with a 1010 mb low pressure center near 15N35W continue to show signs of organization several hundred miles W of the Cabo Verde Islands. Numerous moderate to isolated strong convection extends from 14N to 18N between 31W and 37W. Although environmental conditions are expected to be marginally conducive for development, only a slight increase in organization would result in the formation of a short-lived tropical depression today. Further development will become less likely by the end of the week due to increasing upper-level winds. This low is forecast to meander for the next day, then turn NNW Thu. The chance of formation into a tropical cyclone during the next 48 hours is high. Please, read the Tropical Weather Outlook, at the following website, https://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=2, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 23W, from 20N, moving W at around 10 kt. Scattered moderate convection is noted from 07N to 20N between 15W and 25W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border of Mauritania and Senegal to 11N22W to 09N30W and from 12N38W to 11N47W. The ITCZ extends from 11N47W to 12N58W. Convection in the vicinity of these features is primarily associated with the tropical wave and low pressure, described in the section above. GULF OF MEXICO... Please see the Special Features above for details on Major Hurricane Ian moving through the eastern Gulf of Mexico. A stationary front over the northern Gulf of Mexico has dissipated early this morning and away from Ian, high pressure is building into the region. The rest is dry conditions with NE winds. Strong NE winds are occurring in the northern and central Gulf, with moderate NE winds in the SW. Seas across the basin are on the rise from Hurricane Ian, with seas generally over 12 ft E of 89W, and over 8 ft E of 92W. The remainder of the western and southwestern Gulf has seas of 4 to 7 ft. Major Hurricane Ian is near 25.6N 82.9W with 953 mb at 5 AM EDT moving NNE at 9 kt. Maximum sustained winds are 120 kt with gusts to 145 kt. Ian will move to 26.7N 82.4W this afternoon, inland to 27.7N 81.8W Thu morning, then weaken to a tropical storm inland near 28.7N 81.1W Thu afternoon. Tropical Storm Ian will move offshore to 29.8N 80.7W Fri morning and reach 31.6N 80.8W Fri afternoon. Ian will then move inland and weaken to a tropical depression near 33.6N 81.4W Sat morning. Tropical Depression Ian will be over North Carolina early Sun. Winds and seas will gradually diminish across the Gulf starting Thu night as Ian continues to move northeast of the region. CARIBBEAN SEA... In the wake of Major Hurricane Ian, that is now well N of the area in the eastern Gulf of Mexico, a modest pressure gradient exists over the basin, with significant moisture in place. The result is isolated trade wind showers and thunderstorms over much of the basin, with clusters of moderate convection south of Hispaniola, along the Colombian coast, and in the east-central Caribbean, north of Bonaire. Winds in the central and eastern Caribbean are mainly moderate, with light to gentle winds in the SW basin. Winds in the NW basin are generally moderate and SW, but near western Cuba, fresh to locally strong winds persist in the outermost influence of Hurricane Ian. Seas are 3 to 4 ft, except 4 to 6 ft in the NW Caribbean. In the Yucatan Channel, northerly swell being produced by Ian is leading to seas of 8 to 10 ft. Strong winds and rough seas will diminish over the northwest Caribbean this morning as Ian continues to move north and away from the region, although large N swell will persist in the Yucatan Channel through Fri. Elsewhere gentle to moderate winds and slight to moderate seas will persist across the basin. ATLANTIC OCEAN... Please read the Special Features section above for details on Major Hurricane Ian and on a low pressure W of the Cabo Verde Islands that is likely to develop into a tropical depression today. Elsewhere, a pair of surface troughs disrupted overall high pressure across the basin. These troughs extend from N of 31N47W to 19N43W, and from 31N27W to 17N33W, respectively. Neither trough is producing much in the way of sensible weather, and dry conditions dominate the basin. W of 50W, moderate E winds prevail. To the E, N of 25N, a band of mainly fresh E winds dominate, with gentle E winds to the S. Seas are 4 to 7 ft, with a zone of 8 to 10 ft seas N of 25N between 20W and 40W. Major Hurricane Ian will move to 26.7N 82.4W this afternoon, inland to 27.7N 81.8W Thu morning, then weaken to a tropical storm inland near 28.7N 81.1W Thu afternoon. Tropical Storm Ian will move offshore to 29.8N 80.7W Fri morning and reach 31.6N 80.8W Fri afternoon. Ian will then move inland and weaken to a tropical depression near 33.6N 81.4W Sat morning. Tropical Depression Ian will be over North Carolina early Sun. Expect deteriorating marine conditions off northeast Florida today, with tropical storm or hurricane conditions possible through Fri. Elsewhere moderate to fresh E to SE winds will persist. $$ Hagen/Konarik