Heavy snow and multiple spinouts Thursday morning had officials holding all traffic on Interstate 80 at the California and Nevada state line in the Sierra as a Winter Storm Warning went into effect.

Meanwhile, a swath of the Central and Eastern U.S. was under winter weather advisory, which the NWS issues "for any amount of freezing rain, or when 2 to 4 inches of snow (alone or in combination with sleet and freezing rain), is expected to cause a significant inconvenience, but not serious enough to warrant a warning."

On Wednesday at 2:48 p.m. the NWS Medford OR issued a winter weather advisory valid from Thursday 4 p.m. until Friday 10 a.m. The advisory is for Central Siskiyou County and Northeast Siskiyou and Northwest Modoc counties as well as Modoc County.