How 'wintry mix' is like trail mix
FARGO — Last week we saw a mixed bag of wintry weather, and if you’ve ever had trail mix before, you likely have an idea of what the StormTracker meteorologists mean when they are forecasting a wintry mix. But Mother Nature’s mix isn’t as sweet; in fact, it likely needs some salt to help melt some of the frozen precipitation that’s possible within a wintry mix.
Sleet is the "peanut" of this trail mix of weather. It is one of the most common types of wintry mix, since it can form in two different ways: from the freezing of raindrops or the refreezing of mostly-melted snowflakes as they fall through a layer of air that’s below freezing.
Still in the nut family — but slightly different — are the "cashews" of the bag: ice pellets. These are similar to sleet in that once they reach the ground, they are generally translucent ice, but ice pellets form when water droplets attach to a slightly melted snowflake and then freeze and fall.
Ice pellets and sleet are different than freezing rain, which is the "raisin" of the trail mix bag. If raindrops stay in their liquid form all the way until they reach the ground and then freeze, a coating of ice occurs and can create major problems on streets and sidewalks.
Graupel is always a bit of a treat to see, and that makes it the "M&Ms" of the mix. It looks like Dippin’ Dots, has a softer texture and causes the least amount of travel trouble. Temperatures need to be warmer than freezing at the ground, but colder air above allowing super-cooled water droplets collect and coalesce onto falling snowflakes to create almost a soft hail, or snow pellet.