According to the National Weather Service, a winter storm warning was in effect from the Southwest to the Midwest on Tuesday, affecting more than 17.7 million people as of Tuesday afternoon.
This week, heavy snow is expected in states across the central United States.
As temperatures dropped, some areas saw rain turn to snow early Tuesday.
According to the Indianapolis weather service office, parts of central Indiana can expect six to ten inches of snow Tuesday night into Wednesday afternoon.
The weather service office in Little Rock predicts eight to nine inches of snow in northwest Arkansas through early Wednesday.
winter storm warnings from Texas to New York
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On Tuesday, a winter storm developing across the South will threaten over 15 million people living along the Gulf Coast, including Houston, New Orleans, and Mobile, Alabama, as per The New York Times.
Forecasters with the National Weather Service's Storm Prediction Center warned people in the area on Tuesday to expect potentially damaging winds and strong tornadoes.
The Houston National Weather Service issued a tornado emergency warning this afternoon for a large and extremely dangerous tornado confirmed by radar in southeastern Harris County.
Meteorologists said it was the first on record for the agency's Houston office.
Through the evening, the severe storm threat will continue to move east along the Gulf Coast.
Texas Gov. Greg Abbott said he had directed the Texas Division of Emergency Management to prepare the state's response resources and that authorities at all levels were prepared.
According to FlightAware, a flight-tracking company, at least three dozen flights were canceled and hundreds were delayed at Houston's George Bush Intercontinental Airport.
Pasadena, Texas, a suburb southeast of Houston, said on Twitter that police officers and firefighters were assisting people affected by a tornado that touched down on the southeast side of the city.
The department issued a warning that "dozens of calls" were being received and that assistance might take longer than expected.
In Louisiana, the governor's Office of Homeland Security and Emergency Preparedness issued storm safety messages via Twitter.
The agency warned residents to be on the lookout for another severe weather threat this week.
Similar warnings about storm preparation were issued by the Mississippi Emergency Management Agency.
On Wednesday and Thursday, the risk of severe weather will shift to the eastern Gulf Coast and the Atlantic Coast.
Tornadoes could hit cities from Norfolk, Virginia, to Jacksonville, Florida, later this week.
Large hail is also a possibility as these storms move through.
Winter weather leads to car crashes, deaths, and school closures
State police in New Hampshire reported 90 "crashes and vehicles that have gone off the road" between 5 a.m. and 8 a.m. and 2 p.m. On Monday, EST. "Hazardous traveling conditions" were created by whiteout conditions and snow-covered roadways, according to police, as per USA Today.
There were fatal car crashes on Monday and Sunday due to the winter weather.
A 31-year-old Massachusetts man died in a wrong-way crash on Interstate 290 on Sunday evening, according to Massachusetts State Police.
In Rhode Island, a 25-year-old woman was killed in an Interstate-95 crash early Monday, according to NBC Boston and the Boston Globe.
Last month, a deadly tornado struck New Orleans as a series of storms swept the South.
Last March, two tornadoes struck the city's outskirts, killing at least one person and leaving a path of devastation in their wake.
Oklahoma City Public Schools announced the transition to virtual classes at home in a Facebook post.
Due to poor weather conditions, including the possibility of snow flurries, school districts in Texas, including the El Paso Independent School District, began classes late Tuesday.
Some school districts are planning to close or delay classes later this week.
According to WTRF in Wheeling, West Virginia, some schools in West Virginia and Ohio were considering a late start to school on Wednesday due to forecast snow.
