At around midnight on Wednesday night or early Thursday morning, the residents of Grand Junction experienced a thunderstorm created by the record-breaking Pine Gulch Fire.
Did you hear thunder in Grand Junction last night? That's right...the #PineGulchFire produced hours of lightning and occasionally the bolts were visible. Here is a video taken at our office. The 3rd largest wildfire in Colorado's recorded history is full of surprises. #cowx pic.twitter.com/1u4ZlaEtlG— NWS Grand Junction (@NWSGJT) August 19, 2020
It is not uncommon to see wildfires create their own weather, like fire whirls, and in this case, pyrocumulonimbus clouds. With the right conditions, namely enough moisture those "pyro-clouds" can result in thunderstorms. These storms act like any other with rain, lightning, and sometimes even hail.
According to Ariel Cohen, the Meteorologist in Charge at the National Weather Service in Pueblo, it is the "very strong localized source of heat content" from the fire that creates lower density, buoyant air that rises. Think hot air balloons.
That energetic and unstable movement of air will create the tall billowing clouds and smoke plumes we typically see.
Wildfires impact weather in many ways
Another way fires and weather often interact is with the movement of smoke. Colorado has been seeing a fairly consistent westerly or northwesterly wind flow through the upper atmosphere for several weeks. This has carried the smoke from multiple fires in the mountains, into the front range.
Smoke contains tiny particles that can act as seeds for cloud droplets, which are called cloud condensation nuclei. ALL cloud droplets and rain droplets must have a particle of dirt or something of that sort to form. Wildfires can provide an abundance of those seeds which can lead to the creation of clouds or thunderstorms under the right conditions.