Hurricane Florence is slowly but surely moving toward landfall along the East Coast.

While its winds have decreased, making the storm a Category 2, it's still an incredibly powerful and dangerous storm with extreme rains expected to fall over the course of the next few days in the Carolinas and Virginia as it slows near the coast.

That slowdown could produce historic amounts of rain for that part of the country, if current forecasts hold.

Meteorologist Ryan Maue of WeatherModels tweeted some projections on Thursday morning.

Maue's models suggest that around 17 trillion gallons of rain will fall across North Carolina, South Carolina, Virginia, and Georgia with some spots receiving as much as 30 inches of rain before Florence is finished.

As Hurricane #Florence makes landfall — or tries to very slowly — the rainfall will add up quickly across the Carolinas but also Virginia ...



I'd bet on maximum totals > 30" in many counties ... forecast totals from the adjacent states near landfall around 17 trillion gallons. pic.twitter.com/xcfio0u1fA — Ryan Maue | weathermodels.com (@RyanMaue) September 13, 2018

That is an astounding amount of rain, sure to lead to widespread flooding and billions of dollars in damage. (Over 24 trillion gallons of rain fell on Texas and Louisiana thanks to Hurricane Harvey and we all saw what that did.)

Maue uses multiple models, including data that's agreed upon by the National Hurricane Center, local National Weather Service offices, and the Weather Prediction Center, to come up with his forecasts.

It could (hopefully!) be less or it could be (hopefully not!) more. Maue points to geography as a factor, saying that "these storms have a tendency to really wring out the moisture when they come up against the [Appalachian] mountains."

The tropical cyclone-related rainfall records for the Southeast since 1950. 1870-1949 rain data do not reveal wetter storms for the Carolinas. As 40" local amounts are possible from Florence, the rain forecast is beyond what has been previously seen/witnessed for the Carolinas. pic.twitter.com/BmVZQnZvhj — NWS WPC (@NWSWPC) September 12, 2018

It also won't help matters that a ridge will hold Florence in place, keeping the storm from moving very much for a few days.

"It's blocked right now to the north, to the west, and to the east right now," Maue said. "So the only place it can really go is a little nudge south," until it can eventually go around the ridge and move north.

The forecast amount of rain is hard to wrap your brain around. What does 17 trillion gallons look like?

It would fill 26 million Olympic-size swimming pools (660,000 gallons each).

That much water could fill up nearly 3.5 Great Salt Lakes.

It's enough water to submerge around 81,500 square miles in a foot of water, which would cover the states of Maine, Vermont, New Hampshire, Massachusetts, Connecticut, Rhode Island, and New Jersey.

It's roughly 68 times the amount of water that was pumped out of New Orleans following Hurricane Katrina.

It's important to remember that these numbers are just predictions for now. We won't actually know how much rain falls on the U.S. from Florence until, well, it actually happens.

Maue notes that the heaviest rain could reach inland all the way to Raleigh, which is about 150 miles from the North Carolina coast.

The National Weather Service says local amounts in some areas could top 40 inches.

There has been weather monitoring in the city of Wilmington, NC for nearly 150 years.



The most recent NCEP WPC rainfall prediction for Hurricane #Florence would shatter the historical record for 7-day rainfall accumulation by more than a foot. pic.twitter.com/CsSrSfRMKE — Robert Rohde (@rarohde) September 13, 2018

Whatever the totals wind up being, Florence is sure to bring destructive winds, rain, and floods to the area, meaning a long clean-up and recovery to come.

And then? We all turn eyes to Isaac, rumbling along right into the Caribbean.