Did you see whats happening out near Lake Tahoe and the mountains surrounding it? Here's a few excerpts from the National Weather Service bulletins for today:

...DO NOT ATTEMPT TO TRAVEL ACROSS THE SIERRA PASSES. ATTEMPTING TO TRAVEL IN THE SIERRA WILL PUT YOUR LIFE AT RISK! VERY HIGH SNOWFALL RATES WILL MAKE IT IMPOSSIBLE FOR ROAD CREWS AND EMERGENCY PERSONNEL TO KEEP ROADS PASSABLE AND TO ASSIST STRANDED VEHICLES. IF YOU DO ATTEMPT TRAVEL IN THE SIERRA YOUR CHANCES OF BEING STRANDED FOR MORE THAN A FEW HOURS IS VERY HIGH.....

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