Winter storm warnings and advisories are in effect across seven states because of heavy snowfall and hazardous travel conditions expected over Christmas.
The National Weather Service (NWS) has issued winter storm warnings in Washington and Alaska, while winter weather advisories are active in those states as well as in Oregon, Idaho, Montana, California and Nevada.
A winter storm warning signifies severe weather with heavy snowfall of at least six inches in 12 hours, or eight inches in 24 hours, or significant sleet accumulations. A winter weather advisory indicates less severe conditions, but still warns of snow, sleet or freezing rain capable of causing travel hazards…