Isaias has weakened into a Category 1 Hurricane after making landfall near Destin, Florida, the US National Hurricane Centre says, but it warned of danger from storm surges and floods.
The hurricane was about 105km west-northwest of Panama City, Florida, packing maximum sustained winds of 150km/h, the NHC said in its most recent advisory.
The agency warned against a life-threatening storm surge affecting the Gulf Coast as dangerous hurricane conditions and flash floods spread inland.
The hurricane is expected to cross Alabama and into the Tennessee Valley on the weekend, the agency added.
Nearly 380,000 people in Florida and more than 210,000 in Alabama were left without power as the storm hit shore, the website Poweroutage.us showed.
"Emergency declarations have been approved in Florida and Alabama to ensure federal resources are available to respond to Isaias," Homeland Security Secretary Markwayne Mullin said on X.
Florida's emergency services urged residents to shelter in place and watch for hurricane conditions across the state's north after Isaias hit land as a category 2 storm.
with AP
