CHARLOTTE, N.C. — Did you know heat from forest fires, wildfires, and even volcanic eruptions can create their own weather? They’re called pyrocumulus clouds (official term: Flammagenitus), and sometimes pyrocumulonimbus clouds if they produce thunderstorms and lightning.
Here’s how it happens
The fires are so hot that it forces panels of hot air and smoke upward into the atmosphere. These ‘super-heated updrafts’ happen similarly to updrafts in regular storm clouds, where moisture is forced upward and eventually condenses creating clouds.
In a pyrocumulus cloud, the hot air cools once it reaches colder air in the upper levels of the atmosphere. Just like a regular cumulus cloud, this causes the air to condense using smoke particles from the fire below as what’s called ‘cloud condensation nuclei’. This refers to molecule-attracting particles in the atmosphere upon which water condenses.
(Fun fact: every cloud droplet has a speck of dirt, dust, or salt at its core. Or in the case of a pyrocumulus cloud, smoke or ash particles.)
As the air in pyrocumulus clouds continuously rises rapidly, it can eventually lead to rain, or even thunder and lightning. That’s when it would become a ‘pyrocumulonimbus cloud’, referring to the thunderstorm part.
Oftentimes, when we refer to regular cumulus or cumulonimbus clouds, we discuss how they eventually reach the stratosphere and tap into the cold air, sometimes leading to hail. In this case, as pyrocumulus clouds continue to grow, they send the smoke from the fire into the stratosphere and eventually the jet stream.
This is why wildfire smoke is often able to be seen and felt across different parts of the country, sometimes the world. Once it hits the jet stream, it can travel for thousands of miles.
Contact Brittany Van Voorhees at bvanvoorhe@wcnc.com and follow her on Facebook, Twitter and Instagram.