Frigid temperatures engulfed Texas and other parts of the South on Monday ahead of a rare winter storm expected to bring heavy snow and disruptive ice accumulations to the region into Wednesday, sending residents scurrying to insulate pipes, check heating systems and stock emergency kits.

In Texas, both William P. Hobby Airport and George Bush Intercontinental Airport in Houston announced Sunday night that flight operations would be suspended Monday in anticipation of hazardous conditions.

Meanwhile, people in the Northern Plains to the tip of Maine were experiencing bitterly cold temperatures Monday morning as an Arctic air mass caused temperatures to plunge well below normal values with dangerously cold wind chills, while the East Coast contends with a thick blanket of snow.

Winter storm warnings stretched from Texas to Florida on Monday, with heavy snow, sleet and freezing rain expected in the region into Wednesday. Heavy lake-effect snow was expected in western New York state Monday through Wednesday morning, with 1 to 2 feet possible in some areas including Oswego along Lake Ontario.

Marc Chenard, a meteorologist with the National Weather Service in College Park, Maryland, projected that as many as 70 million residents will be under some kind of winter storm warning in the coming days.

The colder temperatures will dip into the South early this week, where as many as 30 million people starting Monday could see a wintry mix of snow, sleet and freezing rain. The unusual conditions are expected to stretch from Texas into northern Florida and the Carolinas.

Winter storm warnings were in effect in Texas, Mississippi, Alabama and the Florida panhandle on Monday. The storm was expected to impact Texas on Monday evening, then spread eastward through Wednesday morning with heavy snow expected along and to the north of the Interstate 10 corridor with sleet and freezing rain in south Texas and southeast Georgia and northern Florida.

Numerous freeze warnings were in place in northern Florida and along much of the Gulf Coast. Forecasters warned the sub-freezing morning lows will pose a risk to sensitive vegetation and exposed plumbing in areas not accustomed to harsh winter temperatures.

Across Louisiana, officials were urging residents to “stay home, don’t go sightseeing” once the storm and the sub-freezing temperatures hit, warning that travel could be treacherous as roads ice up and refreeze in the coming days.

The worst weather day is expected to be Tuesday, when the storm hits, and freezing temperatures are expected every night through Friday, so warming centers were being readied and towns were working to get homeless people off the streets and into safe places. Supermarkets and other stores in many areas have been packed with shoppers stocking up for the bitter cold stretch.

Much of the Eastern Seaboard will be enduring some of the coldest temperatures this winter.

An area from the Rockies into the Northern Plains will see colder than normal weather over several days, with temperatures forecast to drop to between minus 30 degrees Fahrenheit to minus 55 degrees Fahrenheit on Monday. Sub-zero wind chills are forecast to reach as far south as Oklahoma and the Tennessee Valley.

Minnesota residents were urged to wear appropriate clothing and carry a survival kit for travel. Kristi Rollwagen, director of homeland security and emergency management at the Minnesota Department of Public Safety, also urged motorists to drive with a full tank of gas and a fully charged cellphone to keep in touch with loved ones.

The weather service issued cold weather advisories across the Great Lakes region as high temperatures in many places were expected only to rise into the single digits or teens Monday and today. Night-time wind chills could drop temperatures to minus 20 or lower. Chicago’s high Monday only was expected to hit 10 degrees, while Monday night’s low was targeted at minus 5 degrees.