The National Weather Service issues several different types of headlines to inform the public of hazardous winter weather conditions. Below is the general criteria for each type of headline.
|Watch Type||Guidline Criteria*|
|Winter Storm||Conditions are favorable for a winter storm to produce conditions which meet or exceed Winter Storm Warning criteria.|
|Blizzard||Conditions are favorable for a winter storm to produce conditions which meet or exceed Blizzard Warning criteria.|
|Wind Chill||Conditions are favorable for a winter storm to produce conditions which meet or exceed Wind Chill Warning criteria.|
|Warning Type||Guideline Criteria*|
|Winter Storm||6+ inches of snow in 12 hours or 8+ inches of snow in 24 hours; 1/2 inch or more of sleet.|
|Blizzard||Sustained winds or frequent gusts of 35 mph or more with considerable falling/blowing/drifting snow frequently reducing visibility to less than 1/4 mile for three hours or more.|
|Ice Storm||Accumulations of 1/4 inch or more of ice.|
|Wind Chill||Wind chills of -30 F and below.|
|Advisory Type||Guideline Criteria*|
3-5 inches of snow, snow/wind with < 1/2 mile visibility and considerable blowing and drifting, freezing rain/drizzle < 1/4 inch accumulation when mixed with other precipitation, sleet < 1/2 inch, a mix of precipitation types.
For early and late season events, the snowfall amounts can be lowered to 1-2 inches if travel may be impacted.
|Freezing Rain||Freezing rain and/or freezing drizzle with < 1/4 inch of accumulation.|
|Wind Chill||Wind chills of -20 F to -29 F.|
*Precipitation amounts are expected average values for the forecast area of concern
The criteria for a blizzard is very specific as they are relatively rare events. Occasionally, winter storm warnings are issued containing the wording of blizzard-like conditions. When this terminology is used in a winter storm warning, it means a strong winter storm but falling short of the blizzard criteria.