The United States has recently been experiencing some hazardous weather coditions in the form of severe winter snow storms. One of these particular storms which swept accross the majority of the Northeast of the country has created something that meteorologists have dubbed “thundersleet.”

The new weather description is pretty much what it sounds like. The conditions occur when there is thunder and lightning occurring at the same time as sleet. The conditions are extremely rare and it is understood that less than 1% of snowstorms contain thundersleet.  The rare weather condition is similar to thunder snow and thunder showers as they all take place within a cloud.

U.S based meteorologist John Fuller describes the phenomenon as “Rapid updrafts and downdrafts are causing friction within the cloud producing strong positive and negative parcels within the cloud. When these oppositely charged parcels collide, you get lightning and hear thunder. When the rain falls from the cloud, through a layer just above the ground that is below 32 degrees (today it’s is 25-29 degrees), the droplets freeze into granules that look like diamonds. If the rain aloft that falls is warm enough, it may not freeze until it hits the sub-freezing surface resulting in thunder freezing rain and a glaze at the surface.. The key in having any ‘thunder’ precipitation is convection or strong updrafts and downdrafts causing enough friction and charged particles to produce lightning. Thunder is the sound resulting from the lightning that super heats the air around the bolt.”