A Pineapple Express forms when the jet stream dips south into the tropical Pacific near Hawaii, scooping up warm, moist air and carrying it northeast across the ocean. Named for Hawaii's famous fruit and the storm's origins near the islands, these powerful systems can dump the equivalent of 10 to 15 inches of rain over two to three days.

Another storm will impact Northern California starting Thursday morning. That event is forecast to be somewhat less impactful than the high winds and mudslides on Tuesday that caused a home to collapse in Sonoma County,

A series of atmospheric river storms caused flooding and landslides in Northern California, prompting evacuations and rescue operations.