LOS ANGELES (CBSLA) — Cold, howling winds raked Southern California overnight, wreaking havoc on freeways and bringing down a large tree in Panorama City onto two parked vehicles.

In Panorama City, a white minivan and a blue pickup truck on Calahan Street near Kester Avenue sustained heavy damage from a tree that fell down, blocking access to the residential neighborhood.

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Much of the dry, leafless tree landed on top of the white minivan, crushing its roof. The base of the tree broke through the van’s rear windows. Part of the tree also crushed the hood of the blue pickup truck parked behind the van.

Strong winds also affected holiday getaway traffic on the Grapevine. Several drivers reported seeing huge tumbleweed on the 5 Freeway flying onto and over cars. In the San Bernardino mountains, Caltrans are warning drivers to be ready for snow conditions and to have chains on hand.

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A powerful storm is expected to hit Southern California Wednesday, complicating the travel plans of millions of Southern Californians who already knew they would be contending with holiday getaway traffic.

“Originally we thought that the busiest day was gonna be on Wednesday afternoon on roads and freeways all across Southern California, but now people may be trying to get out a little bit earlier to avoid the wet roads,” said Doug Shupe of the Automobile Club of Southern California. “This afternoon could be busy as well.”

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Shupe said it will be of utmost importance for drivers to focus on the roads, obey the speed limits and not be distracted with mobile devices or food while driving this holiday week in the expected rain and snow.