One time major hurricane and former Tropical Storm Ian strengthened back to a hurricane over the Atlantic Ocean east of Florida on Thursday afternoon. At 5:00 p.m. EDT on Thursday the center of Hurricane Ian was located at latitude 29.3°N and longitude 79.9°W which put it about 240 miles (390 km) south of Charleston South Carolina. Ian was moving toward the north-northeast at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 986 mb.

A Hurricane Warning was in effect for the portion of the coast from Savannah River, Georgia to Cape Fear, North Carolina. The Hurricane Warning included Charleston, South Carolina. A Hurricane Watch was in effect for the portion of the coast from Cape Fear to Surf City, North Carolina. A Hurricane Watch was also in effect for the portion of the coast from the Flagler/Volusia County Line, Florida to Savannah River, Georgia. A Tropical Storm Warning was in effect for the portion of the coast from Cape Fear to Duck, North Carolina. The Tropical Storm Warning included Pamlico Sound. A Tropical Storm Warning is also in effect for the portion of the coast from Vero Beach, Florida to Savannah River, Georgia.

The structure of Hurricane Ian contains elements of a hurricane and elements of an extratropical cyclone. Ian has a warm core in the middle and upper troposphere, which makes it a hurricane. However, cooler, drier air wrapped around the southern side of Ian and a cold front is forming east of Ian. The developing cold front is an element of an extratropical cyclone. Many of the thunderstorms in Hurricane Ian are occurring in bands in the northern and western parts of Ian’s circulation.

The wind field around Hurricane Ian also changed when Ian started a transition to an extratropical cyclones. The circulation around Ian is interacting with a large high pressure system centered over the Great Lakes. The interaction of Ian’s circulation with the high pressure system is causing the strongest winds to be in the northwestern quadrant of Hurricane Ian. Winds to hurricane force extend out 45 miles (75 km) in the northwestern quadrant of Ian. The size of the circulation around Hurricane Ian also increased when it started the transition to an extratropical cyclone. Winds to tropical storm force extend out 400 miles (645 km) in the eastern side of Ian. Winds to tropical storm force extend out 230 miles (370 km) in the western side.

Hurricane Ian will move through an environment somewhat favorable for intensification during the next 24 hours. Ian will move over water where the Sea Surface Temperatures are near 29˚C. An upper level trough over the eastern U.S. will produce southwesterly winds that will blow toward the top of Ian’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification. Hurricane Ian could intensify, if the center moves over the warm water in the Gulf Stream current. More thunderstorms could form near the center of Ian’s circulation and could look more like a hurricane for a few hours. The vertical wind shear will eventually cause Hurricane Ian to gradually continue its transformation to an extratropical cyclone.

The upper level trough will steer Hurricane Ian toward the north-northeast during the next 24 hours. On its anticipated track the center Hurricane Ian could make landfall in South Carolina on Friday afternoon. Ian is likely to be a Category 1 hurricane on the Saffir-Simpson Scale when it reaches South Carolina. Ian will bring strong gusty winds and locally heavy rain. Widespread minor wind damage and electricity outages could occur. Air revolving around the northern side of Ian’s circulation will interact with a stationary front near the coast to enhance the rising motion in that region. The enhanced rising motion could produce very heavy rainfall near the stationary front. Heavy rain could cause flash floods in some locations. Flood Watches are in effect for parts of South Carolina and North Carolina. Southeasterly winds blowing around the northeastern side of Hurricane Ian will blow water toward the coast. A storm surge of 4 to 7 feet (1.2 to 2.0 meters) could occur. A Storm Surge Warning is in effect for the portion of the coast from the Flagler/Volusia County Line, Florida to Cape Fear, North Carolina.