<u were sitting near a window around 12:45 during Thursday's snowstorm, you may have borne witness to a flash of lightning and prolonged rumble of thunder muffled by the blinding snowfall. Thundersnow is an extremely rare event: thought to occur in only 0.07 percent (7 of every 10000) snow storms, with 191 recorded in the last 30 years in the US, mostly in the mountains of the west and in the Great Lakes region. While most thunderstorms can be heard for miles, the heavy snow that accompanies such storms muffles the tell tale crash, constricting the audible range to 1-2 km.
Thunderstorms are usually accompanied by rain, and as such, thundersnows remain a bit of a mystery to climatologists. In a thunderstorm, lightening is produced when turbulence from the churning storm cloud knocks electrons (negative charges) off of the flying water droplets (and snow flakes), creating negative charges that cluster at the base of the cloud and are attracted to the positively charged ground or nearby cloud. The balancing of these charge differences in the form of lightening heats the local air to extreme temperatures. This is closely followed by cooling and collapse of the heated air mass, producing the bang of thunder. Thunderstorms, however, require combining masses of low, warm and humid air with high, cold air, conditions that are rare in winter.
Patrick Market, an associate professor at University of Missouri, has taken on thundersnow as his research topic, chasing the storms with weather balloons equipped with instruments to measure temperature, humidity, pressure and wind speed. Their hope is that by understanding the conditions that produce thundersnow, they will be better able to predict crippling snowfalls that accompany these storms.
Beyond the “Midwest Arc” (MN, IA, WI, MO, KS, NE), thundersnow events are reported to occur around the Sea of Japan, the North Sea and high in mountain ranges. Though they’ve only been actively documented for the last 10 years, accounts of thundersnow date back over 1000 years.
Your Student Naturalists are: Amy Alstad, Jeremy Hayward, Emily Legrande, Lindsey Nietmann, David Smith, Hannah Specht, John Vigeland, Katie Blanchard, Chelsea Clifford, John Kraus, and Mira Alecci
