What the Hell is Thundersnow?

    I remember last year during a snowstorm here in Milwaukee I saw a burst of light coming from the window.  It was so uncanny I actually got up out of my chair during Sportscenter to see what it was --- heck I figured it was someone flashing a light into the window, maybe a car or snow plow some how flashing its lights eight stories up to our apartment, or perhaps it was some type of UFO deciding to come and pick on “me-lady and I”.   To my astonishment, and well perhaps a quick look in my shorts could tell you what I’m about to tell you, IT WAS LIGHTING and THUNDER!

    So it is winter and we have a nice little snowstorm on our hands and we now have to deal with some thunderstorms --- you might ask how is that possible?   This is a phenomenon relatively new to the meteorology world called thundersnow.   In layman’s terms, thundersnow is a thunderstorm causing snow instead of the predictable rain feature associated with most storms.

    It is a really an extraordinary and rare thing to see and to be quite honest I’ve only seen it a few times in my young lifetime.  You need a couple of weather ingredients to come together in order for this to happen --- strong instability, a lifting mechanism, and an abundance of moisture.   Creating instability in the winter is a very difficult thing to do considering instability can be thought of an air parcel and its ability to rise in the atmosphere from its original position.  For that parcel to rise (a lifting mechanism), you need some sort of lift which leads to either a change in temperature, a frontal system, a large difference in temperatures, etc.  In order for thundersnow to occur, the air at the surface has to be warmer than the air above but not warm enough in order for the snow to melt when falling from the clouds.  Now do you understand why thundersnow isn’t an everyday thing?

    In some incidents, thunderstorms can develop in warmer areas and move off to an area where there is still moisture and potential to create thunderstorms but the temperatures drop just enough in order for the rain to convert to snow creating these new “thundersnow“ storms.  Snowfall rates tend to be higher in areas of thundersnow where it would not be unusual to see an inch or two per hour.

    Now you can go tell your friends you know what thundersnow is and they can ask you, “what the hell is thundersnow”?