Hurricane Laura was expected to rapidly strengthen to a Category 4 hurricane on Wednesday on a steady track to hit the Texas-Louisiana Gulf Coast after dark, causing catastrophic damage, the National Hurricane Center said.
The storm, already a Category 3 on the five-step Saffir-Simpson scale for measuring hurricane intensity early Wednesday, was about 290 miles (465 km) southeast of Galveston, Texas, with maximum sustained winds of 115 miles (185 km) per hour, the Miami-based forecaster said.
Category 4 hurricanes can pack winds of up to 156 miles (250 km) per hour.
More than 420,000 Texas residents and another 200,000 people in neighboring Louisiana were under mandatory evacuation orders as state and federal emergency management teams rushed to provide shelter accommodations and get first responders in place for possible rescues.
“You only have a few hours to prepare and evacuate for #HurricaneLaura. Wherever you are by noon is where you’ll have to ride out the storm. Be smart and be safe,” Louisiana Governor John Edwards tweeted Wednesday morning.