WATCH: Drone footage shows insane snowstorm hitting upstate New York

(CNN) -- Snowstorms and record low temperatures whacked much of the country this week -- and there's more havoc coming Wednesday.

About 50% of the country had snow on the ground Tuesday, according to the National Weather Service.

Buffalo, New York, one of the hardest-hit areas, is buried under 5 feet of snow -- and counting.

Buffalo Niagara International Airport, about a 20-minute drive from downtown, is still operating as of around 10 a.m. ET. But many people are having trouble navigating the snow-covered streets to get to the airport, so airlines have started canceling flights, airport spokesman C. Douglas Hartmayer said.

"This storm is basically a knife that went right through the heart of Erie County," said Mark Poloncarz, Erie County executive. "I can't remember and I don't think anyone else can remember this much snow falling in this short a period."

This is only the area's first snowfall of the winter, but South Buffalo has seen almost as much snow in 24 hours as it experiences in an entire season. About 84 inches is normal, but about six feet -- 72 inches -- has fallen since Tuesday.

And it's not going to let up. More snow is expected Wednesday and Thursday, which could set a record high in the history of lake-effect snow events.

Buffalo Mayor Byron Brown Wednesday predicted a "long way to go" before efforts to clear Buffalo's roadways are finished after the snowstorm.

A driving ban remains in effect in south Buffalo, with rescuers -- mostly from the fire department -- using 18 snowmobiles to respond to emergency calls and help stranded motorists, he said.

"It is going to be a slow go," the mayor told reporters. "Historic amounts of snow have fallen. There is no place to put that snow."

Buffalo's Mercy Hospital is short-staffed because many employees couldn't travel.

"Many of our nurses couldn't get in to work today," nurse Shanel Orsi told The Buffalo News. She herself hitched a ride from a snowmobiler to get there.

Thankfully, there were relatively few power outages in and near Buffalo, where only about 450 customers didn't have electricity Wednesday morning, New York State Electric and Gas Corp. reported. That's less than 1% of its customers.

Another blast of cold air will hammer the Midwest and Northeast on Wednesday, while the Southeast could see record lows as temperatures drop into the teens and 20s.

Tuesday was the coldest November morning in the United States since 1976, according to meteorologist Ryan Maue of WeatherBELL Analytics. The average overnight low for the Lower 48 states was 19.4 degrees Fahrenheit.

Snow fatalities

At least six people have died as a result of the storm. Erie County officials said one of the storm-related deaths was from a car accident and three other people died due to cardiac issues that resulted from shoveling snow. In Alden, New York, a 46-year-old man was found dead inside a car buried in 12 to 15 feet of snow, authorities said, and another person was found dead in Genesee County.

Some places in the region have seen more than 5 feet of snow, while others could see 7½ feet more after another round of wintry weather hits this week.

That's the equivalent of a year's worth of snow that's expected to pound some areas over a three-day period, Erie County's Poloncarz said.

"It's probably heavier than anything that we have seen in over 40 years, so it's going to take some time to dig out," Brown said.

Trapped at the police station

The snow left people stranded in cars and turned roadways into parking lots. It also forced residents to seek shelter in unusual places.

About 20 people took refuge at a fire station and 20 others holed up in a police station Tuesday night, authorities said.

And as they waited, those at the fire station got a teeny weeny gift.

A baby girl was delivered there when an ambulance was unable to take her mother to the hospital, Buffalo Fire Commissioner Garnell Whitfield said.

"She was born, she's safe and she's healthy," Whitfield said.

South Buffalo firefighters battled the snow to reach people who had called for help, and emergency responders heading to some calls only found cars abandoned in snow drifts, The Buffalo News reported. Some crews carried stretchers along snow-choked streets because ambulances couldn't drive through, Whitfield told the newspaper.

Whitfield told CNN that firefighters are working overtime, with many pulling 24-hour shifts.

Trapped for over a day

New York State troopers rescued the Niagara University women's basketball team early Wednesday after it got stuck on a bus for more than 24 hours due to the snowstorm.

"We're really tired and really ready to be home," head coach Kendra Faustin said after the rescue.

The team sat on the side of a highway, unable to move. The team was returning home after a game in Pittsburgh when the bus got stuck.

While the team waited for responders, Faustin spoke to CNN's Don Lemon over Skype.

"The roads weren't plowed. It got really bad really fast," Faustin said. "I'm assuming that somebody in the front of the line got stuck and everybody else had to stop, and that's how we got where we are."

For hours, she said, the snow was coming down so hard that they couldn't see anything surrounding the bus.

Buffalo's not alone

All 50 states registered temperatures below freezing Tuesday morning, even traditionally warm ones. Temperatures at Mauna Kea on Hawaii's Big Island dipped to 31 degrees while Florida's Panhandle was in the upper 20s, with freeze warnings in effect.

The cause of this mayhem: Arctic air pouring over the relatively warm waters of the Great Lakes is producing extreme lake-effect snows.

Lancaster, New York, has already received over 40 inches of snow, and it continues to snow at a rate of 4 to 5 inches per hour.

CNN's Ray Sanchez, Daniel Verello, Kevin Dotson, Chuck Johnston, Martin Savidge and Catherine E. Shoichet contributed to this report.