'Disturbing' numbers of people still have not evacuated before Hurricane Matthew - and officials are begging them to go

NHC/Periscope

NHC officials warned residents in evacuation zones to flee Hurricane Matthew in a Periscope video Friday afternoon.

Hurricane Matthew is a big, scary storm, causing major flooding up and down the northeastern coast of Florida.

But some people in evacuation zones from Florida to South Carolina have not left.

Storm surges have topped sea walls and dunes in St. Augustine, Jacksonville, and elsewhere, and there have been reports of major damage to people's homes. National Hurricane Center (NHC) Director Rick Knabb and storm surge specialist Jamie Rohme took to Periscope live video to urge people in mandatory evacuation zones who have not left but still have time to leave immediately.

"The video footage is revealing that the water is coming in with extreme force," Rohme said, "You can't swim in it. It can throw you up against a wall. The bottom line is here is: It is life-threatening conditions."

Rohme pointed to images and videos of flooding shared on social media as a sign of how bad Matthew, already a historic storm, could get up the coast in Georgia and South Carolina.

"What's more disturbing about all this is how many people you had in mandatory evacuation zones who are not leaving," he added, "For the residents further up the coast who still might have time to get out, use this footage to tell you the conditions you're about to experience."

Matthew is expected to track close to the coastlines of Georgia and Florida and to dump significant amounts of rain on North Carolina.

"We already are seeing winds of tropical storm force starting to get closer to the Georgia coastline," Knabb said. "Time is running out quickly in Georgia for you to take protective actions and evacuate. But get out if your emergency manager has told you to leave and they have told you that it is still safe to do so."

Local officials have also taken up creative tactics to convince people to leave:

You can watch the full Periscope video here: