Meteorologist freaks out over thundersnowPosted: Updated:
And why not get excited? How often do we get to see thundersnow? It was the second round of thunder and lightning that morning, and you would have thought with Cantore's excitement, that he had just won the $500 million dollar Powerball Lottery. Although, he went on to exclaim that thundersnow was so much better than that! And maybe it is?
Thundersnow is a rarity in the meteorology world, happening on average only 7.6 times per year in the United States, according to the Weather Channel. Maybe then this is something to get excited about, because Cantore saw and heard 6 different lightning and thunder strikes.
You might be thinking to yourself, thunder and lightning? In a snowstorm? Come on… doesn't seem to make a whole lot of sense. And you are right it doesn't! The general conditions you need for a thunderstorm would be WARM air rising rapidly in the atmosphere causing updrafts and downdrafts to form within the storm. However, this was a snowstorm… and snow = cold. Not snow = warm. So lets examine this further.
In an unstable atmosphere warm air will rise unconditionally, until the air above it starts getting warmer. Granted as your rise in elevation the temperature drops, so as long as the air above is colder, the warm parcel of air will continue to rise, and the air will generally stop rising at the top of the troposphere or around 40,000ft.
Well in a snowstorm though, how could air rise? Well think about it like this… It is 20F degrees outside and snowing at the surface, but at 40,000ft up in the atmosphere it is -40F degrees, that would mean the “warm” 20F degree air at the surface would be able to rise. It doesn't matter the temperature at the surface as long as there is colder above you. When the air is able to rise like this and fast enough it can produced thunder and lightning.
The more common way of seeing thundersnow though, comes with Lake Effect Snow. Cold air moves over the Great Lakes region. The lakes surface temperatures is much warmer and causes the evaporation process to occur as cold air moves over the lake. When the now moist air reaches the lake's edge it begins to rise overland and can have temperature differences of 45F degrees or more causing the air to rise rapidly. This too can cause thundersnow.
The final type of thundersnow event would be through what is called orographic lift, or a change in elevation that is forcing the air to rise. This rising, though due to mountains or elevation change, can cause thundersnow as well.
We contacted the National Weather Service here in Spokane this morning to see if there had ever been any thundersnow in the area, and there were two unconfirmed cases that they mentioned. One was from December 23rd, 2013 near Palouse where the event was described with “high winds and a freak December thunder/lightning storm.” The other case they mentioned was from December 27th, 2010 with no other information included.
So while Jim Cantore may have not won the lottery, he did experience an event that most will not ever see or hear in a lifetime.