On Thursday, the storm was bringing heavy snow and strong winds to the Sierra Nevada and heavy rainfall over parts of coastal southern California.

A sweeping storm system moving across the U.S. threatens to bring tornadoes, blizzards and possibly wildfires to different regions of the country

Dozens of tornadoes are reported from thunderstorms that lit up the radar from Wisconsin to Mississippi in the early hours Saturday.

Most of the rest of north Alabama will have a Level 2 risk, and a small area in the northeast corner of the state will have a Level 1 risk. If storms can develop they have the potential to be intense, especially west of Interstate 65. Tornadoes, damaging winds and hail will be possible.

Chicago will see warm temperatures Thursday before strong winds, severe storms Friday night, and a weekend cooldown with the possibility of rain and snow.

What started as a summer-like day Friday will end with potentially severe storms as a powerful system prepares to sweep across the region, but there's a narrow window of time you'll want to make sure you're prepared for.