The Line Fire in California Creates Dark Pyrocumulus Clouds Followed by Thunderstorms
The Line Fire in California has burned so intensely that it has created its own weather, CNN reported on September 12. Pyrocumulus clouds formed above the fire earlier this week, as the high-resolution weather satellite Landsat-8 observed from several hundred kilometers in orbit. Landsat-8 is a data collection satellite operated by NASA and the United States Geological Survey (USGS).
Pyrocumulus clouds forming over the Line Fire, California. (Image: NASA).
Pyrocumulus clouds develop over strong heat sources like wildfires or volcanic eruptions. The air above these heat sources is rapidly and chaotically pushed upward, causing moisture in the air to condense and form clouds.
However, pyrocumulus clouds also draw in large amounts of smoke and ash from the fire below, making them much darker than typical fluffy white clouds. The Line Fire has pushed smoke and ash to heights of over a kilometer. In satellite images, the pyrocumulus clouds resemble a bomb explosion. While the cumulus clouds to the east of the fire are white and fluffy, the pyrocumulus clouds are surrounded by light brown or yellowish-brown smoke.
The pyrocumulus clouds from the Line Fire later developed into pyrocumulonimbus clouds, which produced lightning and rain, according to NASA. Rain from such a thunderstorm can aid firefighting efforts, but strong winds and lightning strikes in the dry area can ignite new fires.
The Line Fire ignited on September 5, starting in the foothills of the San Bernardino National Forest and subsequently spreading. As of September 12, the fire had consumed approximately 15,000 hectares of land and was only about 21% contained. The disaster has forced thousands to evacuate, damaged numerous structures, and resulted in several injuries.
In the past week, firefighting efforts have faced challenges due to hot, dry weather combined with steep and rugged terrain. Smoke from the fire has created clouds accompanied by thunderstorms. This wildfire-induced thunderstorm system has intensified winds, fanning the flames and causing them to spread further.
More than 3,000 firefighters are battling the Line Fire. “The fire activity in this blaze – according to information we received from firefighting associates – is quite unusual and ‘atypical’ in firefighting science, as I was explained. We continuously have to move and adapt flexibly,” shared Shannon Dicus, the San Bernardino County Sheriff.
