By Georgina McCartney and Brendan O'Brien
HOUSTON (Reuters) -A rare winter storm churned across the U.S. Gulf Coast on Tuesday, breaking snowfall records more than a century old in a southern region where flurries are unusual, as much of the United States remained in a dangerous deep freeze.
A snowstorm warning was in effect for 31 million people - from southern Texas east through Georgia and north to the Carolinas and into Virginia - until Wednesday morning, the National Weather Service said.
With the storm moving east, crews near Houston plowed highways on Tuesday while downtown streets, covered in white, were virtually deserted.
Schools were closed Tuesday and Wednesday as the city, the fourth-biggest in the U.S., expected about 4 inches (10 cm) of snow to fall.
"I've been in Texas my entire life and I have never seen this depth of snow," said Ishan Bhaidani, 29, who owns a fintech consulting company in Houston. "It typically gets more icy but this type of fine snow, this is a first."
Authorities in Houston investigated two deaths that may be weather related, including that of a homeless man who was found near an apartment complex, the Harris County Sheriff said on X.
Snow was also falling in New Orleans, where 9.8 inches (nearly 25 cm) had accumulated by late afternoon, according to the National Weather Service.
Richard Bann, a NWS meteorologist, said that the service was trying to confirm whether Tuesday's snowfall broke a New Orleans record set in 1895 when 8 inches fell.
The last time New Orleans received any measurable snowfall was 2009, according to the NWS.
"Stay home and stay off the roads," said a bundled-up New Orleans Mayor LaToya Cantrell, as winds whipped snow in her face, in a video message to residents on X.
Breaking a 144-year-old record, more than 6 inches (15 cm) of snow fell in Mobile, Alabama, by late afternoon, according to the NWS.
The storm is expected to crawl through Mississippi, Georgia and Florida early this week.
The storm snarled air travel with flights delayed or canceled on Tuesday. More than 1,000 flights departing or bound for Houston's George Bush Intercontinental Airport were canceled, according to Flightaware.com.
Temperatures dipped into single digits Fahrenheit, well below freezing, across the region. Forecasters and local leaders urged residents to protect themselves from frostbite and to take steps to keep their water pipes from rupturing.
Across the South, the snow, combined with an inch of ice accumulation and wind gusts of up to 40 miles per hour (64 kph), could make road and air travel difficult for several days, while threatening to topple power lines and trees, forecasters said.
About 30,000 homes and businesses in southeastern Texas were without power at one point on Tuesday, but by late afternoon that number fell to fewer than 8,000, according to Poweroutage.us.
Atlanta, Georgia, and Montgomery, Alabama, opened warming centers and closed government offices in anticipation of the storm. Numerous school districts canceled classes, according to local news.
To the north, most of the eastern two-thirds of the United States experienced brutally cold temperatures as an Arctic front was expected to linger through at least Tuesday.
Grand Lake, Colorado, was the coldest spot in the U.S. on Tuesday morning at -39 F (-39 C).