The forecast comes days after an expansive storm similarly trekked across the U.S. last week, unloading snow in the northern Plains and bringing tornadoes and wildfires to the South. At least five storm-related deaths in Nebraska and Mississippi were tied to that storm.

Storms that swept through Texas and Oklahoma brought high winds and rain, overturning tractor-trailers and damaging roofs. Power outages were climbing in the storm’s wake, with nearly 400,000 customers without power in Texas, about 30,000 in Louisiana and another 25,000 in Mississippi, according to PowerOutage.us.

A powerful storm dropping drenching rain on flood-prone Southern California is raising concern among forecasters that it could produce a dangerous, widespread outbreak of tornadoes, damaging winds and fires along with a blizzard as it crosses the entire United States in the coming days.