Powerful storms packing heavy rain and snow will lash the US West on Tuesday, a day after thousands of people fled their homes to escape floods, forecasters said. A band of heavy downpours will drench northern California and heavy snow will fall in the Sierra Nevada mountains into Wednesday, exacerbating the threat of flooding, the National Weather Service said. The storms are part of weather system called the "Pineapple Express" that has soaked a vast area from Hawaii to the typically drought-prone states of California and Nevada. Parts of Northern California were soaked by more than a foot of rain over a 72-hour period that ended early Monday, forcing hundreds of people to evacuate and leaving thousands without power. The heavy rains forced rivers out of their banks and toppled trees, among them the famed "Pioneer Cabin" in Calaveras Big Trees State Park that had a drive-thru tunnel carved into its base more than a century ago. Emergency crews in rescue boats and helicopters took advantage of a one-day respite from the rains later Monday to rescue stranded people and assess damage after a weekend of stormy weather that authorities called the heaviest rain in a decade. In the Sierra Nevada mountains, a winter storm warning was in effect until Thursday morning with the potential for blizzard and white-out conditions, said Scott McGuire, a forecaster for the National Weather Service based in Reno, Nevada. Four to 8 feet of snow are forecast through Thursday above 7,000 feet, and the Lake Tahoe area could get between 2 to 5 feet of snow, he said. "People need to avoid traveling if at all possible," said McGuire. Avalanche concerns kept some California ski areas closed for a second day Monday in the Sierra Nevada. In the San Francisco Bay Area, a coastal flood advisory was in effect from Tuesday through Friday, with a forecast for up to 7-foot "king tides" that could pose a flooding risk for coastal roadways, said Steve Anderson, a National Weather Service forecaster in Monterey, California. Flood warnings and a high-wind watch was also in effect Tuesday for the Russian River, which rose to its highest level since 2006 and spilled over its banks early Monday, flooding roads and vineyards and forcing schools to close across the area.
