Helene is threatening an “unsurvivable” storm surge in parts of Florida and damaging winds, rains, and flash floods hundreds of miles inland across much of the southeastern US, forecasters said.

Helene -- which has strengthened to a major Category 4 hurricane -- made landfall in the Big Bend region of Florida on Thursday with 140 mph winds. U.S. Department of Health and Human Services Secretary Xavier Becerra has declared a public health emergency in Florida ahead of Hurricane Helene’s landfall.