Authorities are urging millions of Floridians to evacuate as Hurricane Ian is expected to soon hit the state with extreme winds, catastrophic flooding and life-threatening storm surge.

Various evacuation orders have been issued in counties along Florida’s west coast, where the hurricane is expected to make landfall on Wednesday. Residents in some areas of Tampa, Florida’s third most-populated city, are among those being asked to leave their homes.

“If you’re told to evacuate, evacuate now. Not tomorrow. Evacuate right now,” said Florida Senator Rick Scott on CNN’s “The Lead” Tuesday afternoon. 

Scott said the storm surge could be especially deadly and that many residents will have never experienced a storm so severe.

“We know there’s going to be a lot of storm surge, so if your local emergency officials are telling you to evacuate, that’s because there is a high likelihood of serious wind, rain and water coming you way,” Red Cross spokesperson Evan Peterson told USA TODAY.

Here’s who needs to evacuate and how to evacuate safely:

Should I evacuate? Which Florida counties are evacuating?

You should follow recommendations from local authorities, which can be found on the Florida Division of Emergency Management website.

On Monday and Tuesday, counties including Charlotte, Hillsborough and Lee had issued mandatory evacuation orders for some residents.

As Hurricane Ian makes an expected landfall on Wednesday, an area spanning from Naples, Florida, to counties north of Tampa, Florida, will likely see the heaviest impacts, officials have said. 

What’s a voluntary evacuation? What are zones?

Local officials have issued both mandatory and voluntary evacuation orders for areas in more than a dozen Florida counties. 

If your area is under a voluntary evacuation, it means you are encouraged to leave and you should at the minimum prepare to evacuate.

Evacuation zones are predefined areas based on hurricane risk. They are named after letters of the alphabet, starting with A — the highest risk zone. Each zone is determined based on storm surge data, elevation and evacuation routes, according to Charlotte County, Florida.