AMNA NAWAZ: Welcome to the "News Hour."

Tonight, Florida is bracing for a direct hit from Hurricane Helene, a powerful storm that strengthened to a Category 3 with winds up to 120 miles an hour.

GEOFF BENNETT: Helene is expected to make landfall tonight in just a matter of hours, but many across Florida have been feeling its effects all day and preparing for the worst.

As early as this morning, the outer bands of Helene were already lashing the state of Florida, from Tampa to the Keys, with high winds and swamping streets with heavy rain.

Florida Governor Ron DeSantis today stressed that the effects of the massive 400-mile storm will be felt far and wide.

GOV.

RON DESANTIS (R-FL): Just because you're outside the cone, and I think a lot of those parts on the West Coast of Florida are probably outside the cone, that does not mean that you're not going to see significant impacts.

GEOFF BENNETT: Strengthening today to a Category 3 major hurricane with 120-mile-an-hour winds, Helene could even reach Category 4 strength by the time it makes landfall on Florida's Northern Gulf Coast in just a matter of hours.

The director of FEMA speaking at the White House today with this plea for people in the storm's path: DEANNE CRISWELL, FEMA Administrator: Take the storm seriously.

People in Hurricane Helene's path, you need to listen to your local officials.

If they tell you to evacuate, please do so.

GEOFF BENNETT: More than 40 million people in Florida, Georgia and South Carolina are under hurricane and tropical storm warnings.

Mandatory evacuations have been ordered for at least 20 Florida counties.

An army of thousands of utility workers have been staged across the state, ready to restore power.

Tallahassee Mayor John Dailey, whose city is in Helene's projected path, gave a dire warning.

JOHN DAILEY (D), Mayor of Tallahassee, Florida: If our community remains central in Helene's path, as forecasted, we will see unprecedented damage like nothing we have ever experienced before as a community.

GEOFF BENNETT: Floridians moved quickly all across the state, filling sandbags and shuttering up their homes and businesses.

CHRIS OMAR, Tallahassee Resident: I got a bad feeling about this one.

We have never taken that direct hit.

GEOFF BENNETT: Other families aren't hunkering down.

They're getting out, pets and all, heading to where it's safer.

Some of them in Florida's Big Bend are still reeling from Hurricane Idalia that struck the area just last year.

FRANKIE JOHNSON, Horseshoe Beach Resident: They're saying this one's going to be worse than that one.

So we're looking at -- there's probably not going to be much left.

GEOFF BENNETT: Helene has already made her mark on Mexico's Yucatan Peninsula, bringing more than a half-foot of rain, flooding much of Cancun.

And the storm forced hundreds to evacuate in Western Cuba and knocked out power for hundreds of thousands of people, signs of what could be coming for so many across Florida.

And for the latest on the hurricane, we're joined now by Michael Brennan, the director of the National Hurricane Center in Miami.

Thank you for being with us.

The FEMA administrator said today that the storm is set to hit Tallahassee dead on.

What's the expectation for when the storm makes landfall?

MICHAEL BRENNAN, Director, National Hurricane Center: Well, we're looking at the center of Helene crossing the coast somewhere in the Florida Big Bend area this evening.

It's moving very quickly now to the north-northeast at about 23 miles per hour.

It's going to be moving even faster.

So, right now, it's just about 130 miles west of Tampa.

And that fast motion is going to bring those hazardous conditions to much of North Central Florida, including the Tallahassee region and then inland up into Georgia and the Carolinas overnight tonight and into Friday.

GEOFF BENNETT: Looking at the storm center of circulation, how far out will the impact be felt?

MICHAEL BRENNAN: Well, Helene's a huge storm.

The tropical-storm-force winds, for example, extend out more than 300 miles from the center of the storm, especially out to the east side of the center.

You can see the expansive cloud shield, the showers and thunderstorms extending well northward and northeastward over portions of the Carolinas.

There's been heavy rainfall and flooding in Georgia, Western North Carolina, South Carolina already today.

But you can see the core of Helene is really going to bring those devastating impacts to the Florida Big Bend region, where we're expecting to see storm surge inundation of up to 20 feet above ground level this evening and overnight.

And that's going to really be a catastrophic impact in this portion of the Florida coastline.

And then because Helene is moving so quickly to the north after it makes landfall, it's going to bring the threat of hurricane conditions all the way into Southwestern Georgia, almost to the Atlanta area, but places like Macon, Albany, Bainbridge, Tallahassee, Florida, as we were talking about earlier, are going to see the potential for widespread wind damage, power outages.

And everywhere you see in blue here could see tropical-storm-force winds and hurricane-force wind gusts, especially in places like Atlanta and up along the Southern Appalachians in the higher mountain areas.

GEOFF BENNETT: And, again, folks in the storm's path who have received evacuation orders should certainly heed them.

Is that right?

MICHAEL BRENNAN: Yes, you're really almost running out of time at this point in that storm surge evacuation zone along the Florida coastline, where we're going to see those water levels rise very, very quickly.

If you still have time to get out safely, please do so.

You don't want to be caught in this environment here, especially from Apalachicola down to Chassahowitzka, where we could see that 10 to 20 feet of inundation.

That's going to really create an almost unsurvivable type of environment with destructive wave action.

And evacuation routes can be cut off very quickly when that water starts to rise.

So don't wait until the last minute.

And, remember, you may only have to drive just a few miles, 10 or 20 miles, to get to a shelter outside of that storm surge evacuation zone and get somewhere safe.

GEOFF BENNETT: Michael Brennan with the National Hurricane Center in Miami, thanks for being with us.

MICHAEL BRENNAN: Thanks, Geoff.