A powerful winter storm dropped a coat of snow and freezing rain across the Southeast on Wednesday, leaving almost 300,000 customers without power, forcing the cancellation of more than 3,600 flights, and creating gridlock on roadways in North Carolina.

As Wednesday went on, the storm swept from Alabama, across Georgia and up into the Carolinas on its way toward Virginia and the Washington area.

In Atlanta, where another recent snowstorm had caused massive traffic jams, people seemed to have learned their lesson. Schools were closed. Workers stayed home. The city turned into a kind of wintry ghost town.

But in North Carolina, drivers didn’t seem to have learned the lesson at all.

In both Charlotte and Raleigh, news outlets reported that people headed out onto ice-covered roads in mid-afternoon. The result was the same it had been in Atlanta two weeks ago: creeping traffic, abandoned cars and folks offering stranded motorists a place to stay the night.

In Raleigh, the News and Observer reported that police and emergency crews could not keep up with the multiplying accidents. In one place, a major road had become clogged because cars could not make it up an icy hill. “In the southbound lanes, neon-jacketed men pushed cars one at a time up the hill, while other vehicles sat abandoned under deepening snow on off-ramps nearby,” the newspaper reported.

In Georgia, the National Weather Service reported half an inch of freezing rain had fallen in Augusta and Marietta. By the time the storm passed, the service predicted, up to an inch of ice might accumulate in north Georgia and South Carolina. That could bring widespread power outages, as ice-weighted limbs and power lines fell.

“Make sure you have the supplies you need to stay put for a while,” said Matt Sena, a meteorologist with the National Weather Service in Peachtree City, Ga.

As of 5:45 p.m., those without power included 145,000 in Georgia, and more than 200,000 in the Carolinas.

The storm also caused major havoc in the air travel system, since the majority of flights in and out of Atlanta’s Hartsfield-Jackson International Airport — more than 1,600 in all — were cancelled, according to the Web site FlightAware.

“It’s certainly one of the most aggressive — if not the most aggressive — flight cancellation that we’ve seen” at the country’s busiest airport, said Atlanta airport spokesman Reese McCranie.

Another 700 flights had been canceled at Charlotte’s busy airport. Nationally, the cancellation total was the fifth-highest this year.

Before slamming Georgia, the storm had swept across the Gulf Coast states, leaving behind icy roads in Texas, an inch of freezing rain in northern Louisiana and more than five inches of snow in parts of Alabama.

The storm has been blamed for five deaths so far. On Tuesday, four people died in North Texas, including a Dallas firefighter who was knocked from an Interstate 20 ramp and fell 50 feet. In Mississippi, two weather-related traffic deaths were reported, according to the Associated Press.

Two weeks ago, another snowstorm turned Atlanta into a wintry parking lot, with some commuters needing 22 hours to get home. This time — with the National Weather Service calling for “possibly historic” amounts of ice in Georgia — local officials sought to redeem themselves with good preparation.

Atlanta schools were closed and were slated to remain closed until at least Friday. One of the missteps in the last storm was releasing schoolchildren in the middle of the storm, resulting in stranded buses and stranded parents trying pick up their kids. Many kids had to return and spend the night at school.

On Wednesday, Georgia officials also sought to prevent traffic problems by issuing dire take-shelter warnings more in line with an incoming hurricane.

“The message I really want to share is, as of midnight tonight, wherever you are, you need to plan on staying there for a while,” Atlanta Mayor Kasim Reed said Tuesday night.

It seemed to work. On Wednesday, as the storm turned streets slushy, the roads in Atlanta were largely deserted, according to AP reports.

Wednesday’s widespread flight cancellations came on top of another wave of cancellations Tuesday. On that day, 1,584 flights were canceled as the storm made its way east.

For air travellers, then, this is another bad week in a terrible winter. Last month, as the country was blasted by the infamous “polar vortex,” 39,991 flights were canceled. That was the worst month in three years.

This is the same winter storm — which the Weather Channel has named “Pax,” apparently in the belief that blizzards need personalities — that is expected to bring snow to the Washington area by Wednesday night.

Before then, it was forecast to cause damage in the Southeast on a scale not seen since 2000, or perhaps since a storm in 1973. The reason is ice, which could build up on limbs and bring them crashing down into power lines, cars and homes.

In an early Wednesday memo, the National Weather Service called the storm “an event of historical proportions,” according to the Associated Press.

It continued: “Catastrophic . . . crippling . . . paralyzing . . . choose your adjective.”

Eli Jacks, a meteorologist with National Weather Service, told the AP that forecasters use words such as “catastrophic” sparingly.

“Sometimes we want to tell them, ‘Hey, listen, this warning is different. This is really extremely dangerous, and it doesn’t happen very often,’ ” Jacks said.

●Get the latest area travel updates at Dr. Gridlock.

●Get the latest on the D.C. area forecast at Capital Weather Gang.