A look at precipitation types for Winter Weather Awareness Week

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DOTHAN, Ala. (WTVY) - Winter Weather Awareness Week from the National Weather Service and the Alabama Emergency Management Agency is this week.

Unlike Severe Thunderstorm or Tornado Warnings, a Winter Storm Watch or Warning is typically issued far in advance, from 12 hours to as much as 48 hours. These can warn for freezing rain, sleet, snow, or a combination of these conditions.

For a storm to become officially a blizzard, it must contain winds of 35 miles per hour (by gusts or sustained) and blowing or falling snow must reduce visibility to a quarter of a mile or less for at least three hours.

There are several types of snowfall categories. Flurries are light, can be off and on and generally do not accumulate. Snow showers are stronger, but brief and lead to some accumulations. Snow squalls, typically found in the Great Lakes, are also brief but very intense and often are combined with gusty wind. Finally, snow is considered heavy if it reaches 2 inches or more in 12 hours or less.

The other types of wintry precipitation include:
• Sleet: rain drops that freeze into ice pellets as they are falling to the ground
• Freezing Rain: rain that is not frozen until it makes contact with a surface below freezing
• Wintry Mix: a combination of snow, sleet, freezing rain, and/or rain