Posted by Eagle Staff on February 22, 2013

The winter storm that blanketed most of Missouri with snow and ice included a rare feature – thunder.

The phenomenon, known as “thundersnow,” is extremely rare and is caused by instability in the atmosphere.

It happens when the ground is warm, but air in higher parts of the atmosphere is much colder. It also requires strong wind to create that instability

An MU study shows that between 1961 and 1990 only 191 cases of thundersnow were reported. Snowfall in mid-Missouri began just before 8 a.m. Thursday, accompanied by thunder and lightning.