Hurricane Florence tracker: Storm may bring unprecedented flooding, historical rainfall originally appeared on abcnews.go.com

Hurricane Florence, a dangerous Category 3 storm, is expected to bring catastrophic flooding to the Southeast and may dump as much as 40 inches of rain in North Carolina alone.

The rainfall could be historic and the flooding unprecedented, the National Weather Service office in Newport, North Carolina, warned Wednesday.

"This will likely be the storm of a lifetime for portions of the Carolina coast, and that's saying a lot given the impacts we've seen from Hurricanes Diana, Hugo, Fran, Bonnie, Floyd, and Matthew," according to one National Weather Service meteorologist in Wilmington, North Carolina. "I can't emphasize enough the potential for unbelievable damage from wind, storm surge, and inland flooding with this storm."

Brock Long, the administrator of the Federal Emergency Management Agency, underscored the danger of the storm surge, telling "Good Morning America" Wednesday, "People do not live and survive to tell the tale about what their experience is like with storm surge. It's the most deadly part of the hurricane that comes in, it causes the most amount of destruction."

(MORE: Hurricane Florence's path: What to expect and when)

With the storm not making landfall until at least Friday, residents have more time to evacuate and prepare.

Here is the latest:

-- Overnight the storm shifted south. The coast of the Carolinas will begin to feel Florence's wrath Wednesday night or Thursday morning with gusty winds and increasing surf.

-- There's a chance of tornadoes starting Thursday as the storm meanders near or over the Carolinas.

-- Florence is forecast to stall near the South Carolina/North Carolina coastline into Friday night and then drift towards Myrtle Beach, South Carolina. Florence will likely weaken to a Category 1 storm Friday or Saturday.

(MORE: Couple who lost a home to Hurricane Sandy now grappling with Myrtle Beach evacuation: 'I want to sit down and sob')

-- Regardless of where the storm makes landfall, the impact will be extreme for the Southeast.

-- Hurricane conditions are expected late Thursday night into Saturday morning.

-- Winds could exceed 80 mph from Thursday to Saturday.

-- The life-threatening rain may last for days, flooding tens of thousands of structures, North Carolina Gov. Roy Cooper said Wednesday.

-- Thousands of people are already in shelters, Cooper said.

(MORE: Hurricane Florence to bring dangerous storm surge: What you need to know)

As many as 1.7 million people have been ordered to evacuate in South Carolina, North Carolina and Virginia.

"Today is your last day to get out of the areas that have been placed under evacuation orders," FEMA's Long said. "If you don't do it now, your time is going to be running out. And once the impacts of this storm start to come in, it's going to be very difficult for first responders to get to you."