A powerful storm is dropping drenching rain on flood-prone Southern California and heavy snow on the state’s mountains. It’s the first act of a storm that will unleash a severe thunderstorm outbreak,

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.

Severe thunderstorms, flooding rainfall, damaging winds, wildfires, record temperatures and snow are all possible across the United States.