On 31 July there was a pyroCb that formed in California from the Rocky Fire (40.7 N 123.5 W). According to the Current Fire Information, this fire started on 29 July at 3:29 PM. As of 4 August the fire has burned 65,000 acres. GOES-15 detected the smoke plume and pyroCb cloud, as well as the fire hot spot. Starting at 19:00 UTC on 31 July, the animation below shows visible (.63 μm) on the left and shortwave IR (3.9 μm) on the right (click image to play animation). In the shortwave IR images the red pixels indicate very hot IR brightness temperatures exhibited by the fire source region.

GOES-15 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)
The first image below shows the plume of smoke from the Rocky Fire (courtesy of Ed Joyce and Wildfire Today). The next image is the area of the fire. The red line is the area as of 9 UTC on 2 August and the white line is the perimeter of the fire about 24 hours earlier (image courtesy of Wildfire Today).