17 June 2014 Thunderstorm on the Tundra

An unusual event happened at Toolik today: a late afternoon thunderstorm. First seen over the Brooks Range, a storm rolled north over the tundra. Many lightning bolts were seen. Thunder was heard loud and clear. The low landscape doesn't buffer the sound.

In order for a thunderstorm to form, warm, moist air rises. As the air moves higher, it cools, condenses, and moves downward. This is a classic example of convection. Rain and ice form in the cloud and fall to the ground.

Florida and coastal areas of Alabama, Mississippi, and Georgia have the most thunderstorm days in a year. This makes sense. The states at low latitudes, and are along warm Gulf of Mexico and Atlantic Ocean waters.

Most severe thunderstorm watches are issued for central U.S. states. This makes sense. Warm, humid air moves north from the Gulf of Mexico and meets cooler air moving south from Canada, creating an unstable atmosphere. Tornados are also a threat, giving this area the nickname Tornado Alley.

What doesn't make sense is for thunderstorms to form in the Arctic. At 4:00 PM, just before the storm hit Toolik Lake, the air temperature was ~59ºF (14.93ºC), hardly a warm day. An hour later the temperature dropped to 50ºF (10.16ºC). Still, a storm formed, lasting about an hour and dropping a third of an inch of rain (8.9 mm).

In 2007, a lightning strike started a wildfire, dubbed the Anaktuvuk River fire. The fire lasted for weeks, burning about 400 square miles of tundra. The fire released about two million metric tons of CO2 into the atmosphere. This value exceeds the amount of CO2 absorbed by the Arctic tundra over the past 25 years.

Here's a short video that shows the storm clouds and some lightning. Notice the cloud walls in the photos. Regardless of location, this was an impressive storm.