Hurricane Helene strengthened into a Category 4 storm hours ahead of its expected landfall on Florida’s northwest coast Thursday night as forecasters warned that the enormous system could create a “nightmare” storm surge and bring dangerous winds and rain across much of the southeastern U.

Hurricane Helene in a matter of hours Thursday strengthened from a Category 2 into a massive, destructive Category 4 hurricane as it headed for landfall in Florida’s Big Bend late Thursday

Helene is expected to be a major hurricane — meaning a Category 3 or higher — when it makes landfall on Florida's northwestern coast Thursday evening. As of early Thursday, hurricane warnings and flash flood warnings extended far beyond the coast up into south-central Georgia.