straight from the weather geek;
All of this is being powered by an “atmospheric river†of moisture several hundred miles long from California out over the Pacific.
We could see rainfall rates of half an inch per hour near the Sierra Crest tonight and tomorrow for a total of more than six inches of new rainfall. Snow levels are expected to climb to nearly 10,000 feet on Sunday before dropping to 6,000 feet as the cold front moves through late Sunday. But by then most of the precipitation will have moved east and we will probably see just a few inches of snow at the mountain passes.
Flood warnings are in effect for Sunday along the area’s stream, creeks and rivers, including for the Truckee River between Squaw Valley and Truckee.
Winds will be ferocious at times, with gusts of 140 mph possible at the Sierra Crest.
Monday and Tuesday should be pleasant before another warm storm, not as big as this one, hits us mid-week.