Up to a foot (30 centimeters) of snow already had fallen in parts of Oregon, cancelling flights in Portland. The National Weather Service has issued winter storm warnings and advisories for most of the rest of Montana through Tuesday morning. Hamilton declared a snow emergency, with up to 18 inches (46 centimeters) expected to fall there and in Anaconda by Tuesday. The service said the new snow load coupled with expected winds may result in unstable slope conditions in the Sierra with the potential for avalanches and "rooflanches." "Do not linger under eaves of buildings that have a large quantity of snow on its roof," the service warned.

Source: Fox News February 26, 2019 01:52 UTC