Just as Hurricane Florence closes in on the Southeast, the area covered by hurricane-force winds has doubled — meaning far more people will get blasted with winds 74 mph or greater.

By late Thursday afternoon, the Carolina coasts can expect winds topping 80 mph. And that’s just the prelude to untold days of misery.

What also makes Florence extremely dangerous are the deadly storm surges, mammoth coastal flooding and historic rainfall expected far inland.

“Catastrophic effects will be felt outside the center of the storm due to storm surge as high as 9 to 13 feet. That’s the second story of a house,” North Carolina Gov. Roy Cooper said Thursday morning. “Tens of thousands of structures are expected to be flooded, and many more by rising rivers and creeks.”

And don’t be fooled by the fact that Florence has weakened slightly to a strong Category 2 hurricane. Categories only represent the speed of sustained winds, and these are still destructive.

“I don’t care if this goes down to a Category 1. We’re still going to have a Category 4 storm surge,” ” CNN meteorologist Chad Myers said.

Even worse: Florence is expected to hover over the Carolinas, whipping hurricane-force winds and dumping relentless rain at least through Saturday.

By the time it leaves, it’s expected to have unloaded 10 trillion gallons of rainfall in North Carolina, weather.us meteorologist Ryan Maue said. That’s enough to fill more than 15 million Olympic-size swimming pools.

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Now, many more people and houses are set to endure hurricane-force winds, which extend 80 miles out from Florence’s center.

“It’s cumulative damage,” Myers said. When fierce winds keep up for a long time, homes are “going to start to deteriorate. So will the trees. So will the power lines, as the trees fall down.”