At least 46 million people were under a winter storm warning as of Thursday as the storm spreads along the Gulf Coast Friday, according to the weather service. The storm should weaken by Saturday, bringing lighter snow between 1 and 3 inches to parts of the Northeast, the Mid-Atlantic and the Ohio Valley before exiting off the Carolinas.

Kansas City International Airport, for example, has an 85% chance of snowfall exceeding .1 of an inch, according to data from the weather service. The probability of higher snowfall totals drops rapidly, with only a 50% chance of snowfall exceeding 1 inch. The chance of 2 inches or more of snow is less than 10%.

Some southern states are bracing for their biggest winter storm in several years as snow falls from the Rockies to the East Coast. On Thursday, the weather starts to deteriorate in northern and western Texas,

A powerful winter storm that unleashed heavy snowfall and coated roads with ice across much of Texas and Oklahoma has pushed into the South, leading governors to declare states of emergency and prompting widespread school closures.