On 24 August a pyroCb formed from the Henry Creek Fire in Idaho. GOES-15 detected the smoke plumes and pyroCb cloud, as well as the fire hot spot. The pyroCb (43.4º N, 111.7º W) formed around 23:45 UTC . Starting at 23:00 UTC on 24 August, the animation below (also available as an MP4) )shows GOES-15 (GOES-West) 0.63 µm visible (left) and 3.9 µm shortwave IR (right) . In the shortwave IR images, the red pixels indicate very hot IR brightness temperatures exhibited by the fire source regions.
Since GOES-15 has a lower resolution the brightness temperatures appeared warmer. A 1-km resolution NOAA-18 image at 00:02 UTC on 25 August (below; courtesy of René Servranckx) showed the cloud-top IR brightness temperature of the pyroCb to be -41.5º C (green color enhancement).