"Pineapple Express" storm effects feared in western U.S.

(CBS News) The western U.S. is bracing for another round of torrential rain Thursday. It is the second of three storms this week that could cause trouble over a widespread area.

Experts say the rain that fell in California on Wednesday is just a small taste of what's to come, the first salvo in a triple-threat of storms, which has already caused power outages in Saratoga, Calif., downing trees and contributing to a big rig accident in Sacramento. Workers are clearing the roads before two more storms hit later today and Saturday.

Evilyn Taft, a meteorologist, explained, "There's a lot of moisture that comes with these systems. So we're seeing a lot of rain. And we're seeing it day after day after day."

It's a so-called "Pineapple Express" weather system -- a jet stream that starts near the pineapple-growing territory of the Hawaiian islands. Some call it a rain train, with a final and potentially devastating destination in the western U.S.

Taft said, "The Pineapple Express can cause a lot of damage. It's a warm storm and it brings a lot of water along with it. But on top of that, it could bring snow to the higher elevations, but it'll turn around and it'll melt that snow right away. And, in turn, that'll turn into additional flooding."

Previous "Pineapple Express" storms brought as many as 14 inches of rain. Forecasters say this system could bring as much as 12 inches of rain to the coastal mountains, increasing the threat of widespread floods.

There's a big concern for people living in areas burned by last summer's wildfires in Northern California. The ground in those areas can become saturated with water very quickly and that can cause flooding and mudslides.

Watch Carter Evans' full report in the video above.