Difference Between a Blizzard and a Storm
- Heavy snowfall is most closely associated with a blizzard. Under the right conditions, however, heavy snowfall is not required for a storm to be classified as a blizzard. The National Weather Service will issue blizzard warnings if they suspect that snow that has already settled on the ground will be kicked up and blown around by heavy winds, creating conditions similar to those that would occur with a fresh heavy snowfall.
- Like hurricanes, blizzards carry very strong winds with them. While most winter storms contain wind, only those with sustained winds above 35 miles per hour can qualify as a blizzard. These winds can lead to whiteout conditions, making traveling on roads extremely hazardous for motorists and pedestrians.
- The combination of heavily blown or falling snow, and the strong winds required for a blizzard can create low-visibility weather conditions. In order for a storm to become a blizzard, there must be visibility of 1/4 mile or less on the horizon. This low-visibility condition is hazardous for motorists, but also planes and ships, often causing major delays at airports and docks.
- In order for a storm to become a blizzard, it must meet each of the above three criteria for at least three hours. If the National Weather Service expects that this will happen, they release a "Blizzard Warning" over public channels of broadcast, and on their website. During a "Blizzard Warning," travel is discouraged unless it is an emergency, and delays should be anticipated at airports.
