A major winter storm slammed the southern United States Tuesday, blanketing parts of the Gulf Coast with record-breaking snowfall in a region largely unaccustomed to extreme winter weather.The storm, impacting areas from Texas to Florida and up the Carolina coasts, led to widespread closures and escalating travel disruptions Wednesday, including stranded motorists and delayed flights. Airports in Louisiana, Mississippi and Florida closed Tuesday due to unprecedented snowfall.More than 25 million people are under winter weather alerts from Florida to Virginia early Wednesday all while much of the central and eastern US face temperatures running 20-30 degrees below average.Snowfall records brokenNew Orleans shattered its modern all-time daily snowfall record on Tuesday, receiving 8 inches of snow, far surpassing the previous record of 2.7 inches. The city has recorded more snowfall this month than Anchorage, Alaska, which has seen nearly two inches in January.Other Southern cities also broke long-standing snowfall records: Mobile, Alabama, reported 7.5 inches, exceeding the previous 3.6-inch record from 1973. Pensacola, Florida, recorded 7.6 inches, surpassing its 2.3-inch record from 1954. Milton, Florida, had a preliminary total of 8.8 inches, potentially breaking the state-wide snow record.Widespread road closuresWith cold weather conditions across the region this week, roads could remain hazardous as snow melts and refreezes.In Louisiana, Interstate 10 from the Louisiana/Texas state line to Baton Rouge a roughly 150-mile stretch was closed in both directions due to deteriorating road conditions Wednesday morning, according to the state Department of Transportation and Development. Nearly 30 state roadways were closed as of Tuesday, including the Lake Pontchartrain Causeway the nations longest bridge over water.To help treat roads, New Orleans has hired 14 snow plows from an Indiana-based company, city director of homeland security and emergency preparedness Collin Arnold told reporters Tuesday. The initial focus will be on clearing critical routes, while crews will tackle main thoroughfares, he said.Meanwhile, roads in Alabamas Escambia, Mobile and Baldwin counties were deemed impassable and closed due to the storms impact, officials said.Nineteen counties in Mississippi were still reporting ice on roads and bridges at 9 p.m. local time Tuesday, with black ice remaining a significant threat into the night, the Mississippi Department of Transportation said on social media. Authorities advise that only emergency travel is recommended in the affected areas.In Georgia, state officials held a news conference on Tuesday cautioning residents to stay off the roads, particularly those covered in fresh snow, as conditions are ripe for melting and immediate refreezing. The Georgia Department of Transportation has treated over 43,000 lane miles with 1.7 million gallons of brine to mitigate ice accumulation, officials said.Airport disruptionsMore than 1,200 flights have been canceled nationwide as of Wednesday morning, primarily affecting routes to and from Texas and Louisiana, according to FlightAware.Key closures include both of Houstons major airports George Bush Intercontinental and Hobby as well as Louis Armstrong New Orleans International Airport, where all flights have been canceled and operations expected to resume Wednesday. Lafayette Regional Airport in Louisiana has also shut down due to icy conditions.In Mississippi, Gulfport-Biloxi International Airport has closed its terminal and runway until conditions improve. Airports in Mobile, Tallahassee, and Jacksonville halted and are aiming to reopen at noon on Wednesday.Deadly conditionsNationwide, at least nine fatalities have been reported due to the severe cold affecting large parts of the country. On Tuesday, at least five people died in a vehicle accident caused by icy conditions in Zavala County, Texas, according to CNN affiliate WOAI/KABB, citing authorities.Additionally, authorities are investigating two deaths in Austin as potential cold-related fatalities, though the medical examiners office has not confirmed the causes. In Georgia, officials reported one hypothermia-related death, noting the individual had been outside the previous night.While the wintry storm has had a visceral impact on the Gulf region, below-freezing temperatures are also affecting much of the US. An 80-year-old man in Milwaukee is suspected to have died from hypothermia after falling outdoors early Sunday, according to the Milwaukee County Medical Examiners Office.As temperatures plunged below freezing this week, the plight of those experiencing homelessness became increasingly dire.In San Antonio, Mariah Pena and Daniel Vertiz felt the weight of this reality when Pena found a woman seeking refuge in their dog kennel on the porch Sunday, CNN affiliate KSAT reported. Startled yet desperate, the woman explained that she had nowhere else to turn.Though the couple hesitated to invite a stranger into their home, they felt an imperative to help, thinking that even a makeshift shelter would offer respite from the life-threatening cold. Who knows what could have happened if she were left out on the streets? Vertiz told the outlet.Forecast aheadAs snowfall subsides, officials are warning that any melting snow from Tuesday will refreeze as temperatures plunge.The greater Houston area saw temperatures dip into the mid-20s, with forecasts predicting a drop to as low as 18 degrees overnight. An extreme cold warning remains in effect until 10 a.m. ET Wednesday, with wind chills making it feel as cold as 10 degrees. The highest accumulation in the greater Houston area was reported three miles southeast of the city, where 4.0 inches fell.While temperatures are expected to rise above-freezing on Wednesday, the forecast warns of another freeze overnight into Thursday morning, which could lead to hazardous road conditions once again.Widespread snowfall totals across the Carolinas and Virginia could reach 2-6 inches with isolated totals potentially reaching 8 inches. Across Georgia and Florida, snowfall totals of 2-4 inches are possible along with ice up to a quarter inch. The bulk of the snowfall will end across the Carolinas and Virginia Wednesday morning.