It is here, Atlanta. The major ice storm that has the potential to leave thousands without electricity started moving into the area early Wednesday.

"This is one of Mother Nature's worst kinds of storms," Gov. Nathan Deal said Tuesday afternoon. "We're not kidding. We're not crying wolf."

Deal declared a state of emergency for 91 Georgia counties. Earlier Tuesday, President Barack Obama declared an emergency in the State of Georgia and ordered federal aid to supplement state and local response efforts.

Forecasters have warned of the storm for days, and government leaders have put the wheels in motion, literally, to keep metro roadways as clear as possible from the ice. It’s being called catastrophic and historic, and those aren’t words tossed around lightly, according to meteorologist Brad Nitz with Channel 2 Action News.

Shortly after midnight Wednesday, as predicted, rain and sleet began moving into metro Atlanta. And the precipitation is expected to last until Thursday morning, chief meteorologist Glenn Burns said.

Here’s what you need to know:

The forecast: We'll be dealing with snow and ice for a couple of more days before warmer temperatures move in. Freezing rain is expected to  continue during the day Wednesday, with snow totals of up to 10 inches possible in northeastern counties, Nitz said.

Wednesday’s high won’t be above freezing and heavy accumulation of ice is expected. Strong winds will also add to the mix Wednesday afternoon, Nitz said. Wind speeds of 20 to 25 mph are expected, making ice-laden trees and power lines even more vulnerable.

The snow and ice will continue through early Thursday, when temperatures should reach the upper 30s, Nitz said. Friday and Saturday should see warmer weather, with highs in the mid-40s, climbing to the mid-50s by Sunday. Some long-range forecasts have temperatures rising to the upper 60s by the end of next week.

The roads: Crews are working 12-hour shifts, ready to dump tons of de-icing material on metro interstates began Tuesday around 9 p.m., according to state and local leaders. A total of 70 teams – each comprised of a truck fitted with a plow and sand/salt spreader and another follower truck – will be simultaneously set in motion in different districts around the metro Atlanta area.

Karlene Barron, a GDOT spokesman, said drivers should stay off the roads until at least Thursday morning.

“It’s really only emergency vehicles that need to be out there,” Barron said.

If you must drive on Atlanta interstates, use the two far right lanes of the road, which are the priority for GDOT crews. Track major traffic incidents here.

Georgia billboard companies on Tuesday began broadcasting live Twitter feeds from the Georgia Emergency Management Agency and Georgia Department of Transportation on hundreds of digital billboards.

The airport: Some 2,200 Atlanta flights have been canceled as heavy winter storm conditions loom, and the world's busiest airport now expects only about 300 flights to operate Wednesday. Both Delta Air Lines and Southwest Airlines were forced to suspend the bulk of Wednesday's operations in Atlanta. Travelers whose flights are canceled are getting notifications if their contact information is in their reservation, according to Atlanta-based Delta. Affected customers are given an option to rebook.

Public transportation: No MARTA buses will run Wednesday, including no paratransit buses, the transit company announced late Tuesday. The rail system will run, but trains will run on a weekend schedule. Rail service will begin at 4:35 a.m. Wednesday with trains running approximately every 15 minutes on all lines until about 2 a.m. on Thursday, a MARTA spokesman said. But the rail schedule could change, depending on conditions. MARTA is asking rail customers to be patient and plan extra time to complete their trips. For the latest information about MARTA and any service updates, please visit itsmarta.com. Amtrak also said it has suspended some services in the Southeast, including in Atlanta.

Power companies: The ice is expected to bring down trees and power lines, likely leaving many without electricity. But utility crews were gearing up Tuesday night, prepared to respond.

In Cobb County, the Six Flags White Water parking lot served as a staging area for Georgia Power crews. The staging area setup includes sleeper trailers with beds, restrooms, shower facilities and a catering tent for crews, and it expected to serve about 500 crew members. Six Flags White Water is located on Cobb Parkway in Marietta.

Not sure what to do if you lose power? Here are some tips.

Schools: Most school systems have cancelled Wednesday's classes. Some systems, including Fulton County, also cancelled Thursday classes. Here is an updated list of closings.