NASA Earth Observatory wrote on August 9, 2018:
In July and August 2018, towering plumes of smoke have risen from several fires in northern California. Though heavy rains ended the lengthy drought that parched California, trees and vegetation killed during that dry spell still linger in California’s forests. With all that extra fuel priming the state’s forests for large fires, a period of hot and windy weather this summer made it extremely difficult for firefighters to maintain the upper hand.
One of the fires – the Mendocino Complex – surpassed the 2017 Thomas fire to become California’s largest fire on record. As of August 7, 2018, the fire had charred 1,200 square kilometers (460 square miles), an area about the size of New York City. Another blaze, the Carr fire near Redding, had torched more than 1,000 homes, making it California’s sixth most destructive fire on record. Several thousand firefighters are battling each of the large fires in California.
Scott Bachmeier, a research meteorologist at the University of Wisconsin-Madison, said:
Many of the larger fires in California have produced pyrocumulus clouds on an almost daily basis. While much of the smoke is being ejected to high altitudes and transported eastward across the lower 48 states, some of it has been confined to the boundary layer, reducing visibility and affecting air quality near the fires.
— WeatherOptics (@weatheroptics) August 8, 2018
Bottom line: Space image of a pyrocumulus cloud – aka a fire cloud – over northern California.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.