GEOFF BENNETT: Welcome to the "News Hour."

In the span of 24 hours, Helene in the Gulf of Mexico has strengthened from a tropical storm into a hurricane.

Over the next 24 hours, it's expected to grow even stronger, and it's barreling straight toward Florida.

Floridians have been filling sandbags, preparing to hunker down in the face of heavy rains, storm surge and floods.

Earlier today, Florida Governor Ron DeSantis urged residents to act now.

GOV.

RON DESANTIS (R-FL): Time to make the preparations and put your plan in place today, but that time is running out.

This storm, I think, as you know, is basically in the area of Cuba and the Yucatan Peninsula.

It's moving past that, and then it's going to have pretty much a clear runway in the Gulf of Mexico.

GEOFF BENNETT: Current forecasts show Helene will arrive as a dangerous Category 4 hurricane tomorrow.

Jamie Rhome is the deputy director of the National Hurricane Center, and he joins us now from its headquarters in Miami.

Thanks for being with us.

So, Jamie, where is Helene right now, and what will the next 24 hours look like?

JAMIE RHOME, National Hurricane Center: Well, Helene is centered down here just to the north of Cancun, Mexico.

It's now emerging out over the open waters of the Eastern Gulf of Mexico, where conditions appear especially favorable for development, possibly significant development.

And we anticipate Helene to go on and become a major hurricane before it tracks somewhere here over the Florida Panhandle or Big Bend region late on Thursday.

GEOFF BENNETT: And what about the potential, Jamie, for storm surge and flooding?

What does that look like right now?

JAMIE RHOME: Unfortunately, it has increased over the last 12 hours.

With the wind increase and the size increase that we have been talking about all day, so goes the surge risk.

And we're now looking at the potential for 15 to 20 feet.

You read that correctly, 15 to 20 feet of storm surge in the Big Bend region, with significant surge less than that, but significant surge extending basically all the way down the Florida west coast.

So this is going to have a big and lasting impact for much of the Florida peninsula.

And, unfortunately, it's going to spread, spread its impacts deep into the Southeast, especially over Southern Georgia.

GEOFF BENNETT: So it's expected to land as a Category 4 storm right now.

What does that suggest in terms of wind strength?

JAMIE RHOME: For those in the path of that wind, it would be catastrophic damage.

Category 4 winds are capable of significant structural damage to all but the most sound and secure buildings.

So anything that isn't up to modern building codes or your modern standards are probably going to sustain substantial damage, widespread power outages, trees down.

Especially in and around Tallahassee, they have got a really big tree canopy.

Impassable roads, down power lines, it's just going to be a big mess for people who are in the path of the storm.

GEOFF BENNETT: So people who are in that path of the storm and the affected areas, they should really heed those evacuation warnings, I'd imagine.

JAMIE RHOME: Oh, absolutely.

Those evacuation orders are issued based off the storm surge forecast from the National Hurricane Center.

And, in fact, we have been on the phone with the emergency managers all day trying to assist them in that evacuation decision.

It's a hard decision for them to make, but it's based off the best and most reliable forecast that are issued straight from here.

GEOFF BENNETT: Jamie Rhome with the National Hurricane Center, thanks for your time this evening, sir.

We appreciate it.

JAMIE RHOME: Thank you.