MEMPHIS, Tenn. (WMC) - The thunderstorm anvil cloud is a common cloud and they can be spotted on any given hot summer day in the Mid-South.
An anvil cloud is made of ice particles; these frozen particles form in the highest levels of thunderstorms or cumulonimbus clouds. The cool shape that you see with the flat top is due to rising air in storms. The air expands and spreads out as the air hits the bottom of the stratosphere. The name anvil comes from its similar look to a tool that is used by metal workers.
The air that rises from the anvil is cooler than the air of the stratosphere. This prevents the air from the anvil from rising beyond the stratosphere. Anvil clouds can be spotted many miles away. Sometimes, these thunderstorm tops can be seen over 100 miles away.
Another cool thing with anvil clouds is that on some occasions you may be able to see streaks of snow called “virga” which falls from the outer part of an anvil cloud. The snow evaporates as it falls through drier air that’s around the upper part of the storm.
You may notice clouds that look to push through the flat top or bubble up. This is known as the overshooting top. This is a sign that a storm is getting stronger.
One of the most dangerous features of an anvil, is the lightning it can produce. Typically lightning originates from the the lower portion of a thunderstorm. Anvils can produce some of the most dangerous and deadly lightning and that is lightning that comes from the higher portion of an anvil.
A bolt out of blue, which is lightning that strikes when there is blue sky and storm that generates it can be up to 30 miles out! This why it’s called a bolt out of the blue. This type of bolt comes from an anvil. These strikes are characterized by a positive charge and can be 10 times more powerful than a typical lightning strike.
So if you see an anvil, look out because they are fascinating yet dangerous. Please observe from a safe place.