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.

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.

A huge storm system crossing the U.S. threatens to unleash tornadoes Friday in the Mississippi Valley, blizzards in the northern Plains and dry, gusty conditions in Texas and Oklahoma that pose an extreme risk of wildfires.