A ‘Category 5’ winter storm ahead?

Most weather watchers are familiar with using numbered categories to describe hurricane intensity. The Saffir-Simpson Hurricane Wind Scale is still considered the gold standard for assessing hurricane wind severity.

University Corporation for Atmospheric Research COMET program

Now, National Oceanic and Atmospheric Administration forecasters are testing a new experimental scale for winter storms.

It’s called the Winter Storm Severity Index. The index assesses categories to winter storms based on expected snowfall and other winter weather factors. The basic index categories assess impacts ranging from limited to extreme.


The categories are mapped to show impact zones on inbound winter storms.

Here’s a sample forecast map from this quiet weather day across Minnesota.

Historically, Minnesota’s famous Category 5 winter storm was the Halloween megastorm in 1991, which dumped 28.4-inches at Minneapolis-St. Paul International Airport. Last April’s Dayton’s Monkey Blizzard would rate a Category 4. That storm produced 15 to 22-inches of snow in the Twin Cities.

Keep an eye out for Winter Storm Severity Index snowstorm categories in upcoming snow seasons.

  • Whew, when I saw the headline I thought it was a forecast. Glad it’s just an explanation of the categories! Happy Friday.

  • patman683

    Agreed. This headline definitely smells a bit click-baity.

  • Chris C

    So 1″ of snow in ATL will be 5? (LOL) I wasn’t here for ’91 but ’18 wasn’t a 4 IMO. The roads were fine a couple hours after it stopped snowing. It wasn’t a couple days to recover. I was out driving in the worst of it in. It was slow but doable. But either way seems odd a scale would be several 5’s a year in the south and one 4 or 5 every 30 plus years in the north? The tornado and hurricane scales aren’t location dependent.