Winter storms could bring 4-8 feet of snow to parts of West. See forecast.

The search for Nancy Guthrie, "Today" show host Savannah Guthrie's 84-year-old mother, continued Monday, Feb. 16, more than two weeks after her disappearance. Nancy Guthrie, whose health her family has described as fragile, was allegedly kidnapped earlier this month in a case that has now

captured the nation's attention and brought federal law enforcement to Arizona to aid local police in a desperate search for her abductor. Nancy Guthrie was first reported missing Sunday, Feb. 1, and a reward of $100,000 has been offered for information leading to her recovery, double the initial reward of $50,000. Follow along for the latest updates.After weeks of dry, warm weather, much of the West will see a wet, cool week with drenching rain and heavy mountain snow, forecasters warned.

"Snowfall in the Sierra, Cascades, and Rockies will be measured in feet and yards," said Weather Trader meteorologist Ryan Maue in an e-mail to USA TODAY. "Expect major travel impacts from heavy snow, and mountain travel is highly discouraged during this time!" the National Weather Service in Sacramento, California, said. In addition to snow, a multitude of other hazards could arise this week, ranging from localized flooding and tornadoes to gusty winds, according to AccuWeather.California will bear the brunt of the storminess: "It will be a wet week across California as a series of storm systems slam into the state," said AccuWeather meteorologist Kai Kerkow in an e-mail to USA TODAY. "Multiple inches of rain will fall across much of the state, with several feet of snow expected in the Sierra."How much snow will fall? Through Wednesday, Feb. 18, about 4 to 8 feet of snow is expected in the Sierra, with the heaviest period likely from Monday night, Feb. 16, through Tuesday, Feb. 17, AccuWeather said. Snow levels will drop to 4,000 feet by Monday evening, Feb. 16. All Sierra passes could close at times on Monday, Feb. 16, to Wednesday, Feb. 18, including multiple closures of Donner Pass along Interstate 80, according to AccuWeather.Hazardous but beneficial Although the rain and snow will be hazardous, the precipitation will be helpful for California's water needs: "The state’s snowpack is running well below average for this time of year due to a dry and warm weather pattern that lasted from the middle of January through the beginning of February, so the active weather pattern will be beneficial for the summer water supply," added Kerkow. The storms will "make up for lost ground from the past several weeks of extraordinary warmth," Maue said. Further inland, much of the Rockies is in urgent need of moisture, AccuWeather said. Before this week, water stored in snowpack was near record-minimum levels in Colorado and Utah, a critical portion of the Colorado River basin that serves approximately 40 million people.Severe thunderstorm, tornado risk Thunderstorms are expected Monday, Feb. 16, across the Los Angeles Basin, northern portions of the Central Valley and coastal Southern California. Storms could produce damaging wind gusts, frequent lightning, downpours and an isolated tornado, according to the Storm Prediction Center.The risk zone includes densely populated areas from San Luis Obispo County south through San Diego County, with additional spin-up tornado potential around the Sacramento Valley, AccuWeather said. In addition to the threat of severe storms, flash flooding from heavy rain is possible, particularly in urban areas and near burn scars, the weather service said. AccuWeather said that cumulative rainfall totals of 1-2 inches are expected in places like San Diego and the Central Valley, increasing to 2 to 4 inches near the Los Angeles Basin and into Northern California.