(Richmond, Va.) — Gov. Ralph Northam has ordered mandatory evacuations for some parts of Virginia as Hurricane Florence approaches.

Coastal Zone A, which contains 245,000 people, is under the evacuation order. Zone A contains parts of Hampton Roads and the Eastern Shore.

The evacuations begin at 8 a.m. Tuesday.

Governor Northam’s decision to call for a mandatory evacuation was based on the most recent data and forecasts available, which show the potential for flooding in coastal areas.

While the storm’s track may still change, the models agree that Virginia can expect significant impacts—coastal storm surge, inland flooding that may be severe, high winds, and widespread power outages.

Northam said that Zone A is the lowest-lying, most flood-prone area of the four zones.

Northam has declared a state of emergency for Virginia, to begin preparation of state assets. Also on Monday, Governor Northam requested a federal emergency declaration in advance of the storm, to ensure the availability of federal resources to help Virginia with storm response.