Calf Canyon Fire produces a pyrocumulonimbus cloud

May 10th, 2022 |

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Infrared Window (10.35 µm, bottom left) and Cloud Top Temperature derived product (bottom right) [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.35 µm) and Cloud Top Temperature derived product images (above) showed that the northern portion of the Calf Canyon Fire/Hermits Peak Fire in New Mexico produced a pyrocumulonimbus (pyroCb) cloud on 10 May 2022. Extreme fire behavior was aided by surface wind gusts in the 42-64 mph range and very dry air within the boundary layer (along with very dry fuels from the ongoing drought); these large fires also burned very hot, with 3.9 µm Shortwave Infrared brightness temperatures reaching 138.71ºC — the saturation temperature of ABI Band 7 detectors. Coldest 10.35 µm cloud-top brightness temperatures exhibited by the pyroCb cloud were around -45ºC (lighter blue enhancement), with the Cloud Top Temperature product showing values as cold as -54ºC (red pixels).

In a comparison of NOAA-20 VIIRS True Color RGB, False Color RGB and Infrared Window (11.45 µm) images valid at 2057 UTC (below), the coldest cloud-top infrared brightness temperature was -59ºC. These images were acquired and processed using the Direct Broadcast ground station at SSEC/CIMSS.

NOAA-20 VIIRS True Color RGB, False Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

During the preceding nighttime hours, a toggle between Suomi-NPP VIIRS Day/Night Band and Shortwave Infrared images valid at 0847 UTC or 2:47 am MDT (below) showed the bright emitted light and hot thermal signature of active fires along the periphery of the burn area — especially along the northern fire front, which eventually produced the pyroCb cloud.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

An evolution of the recent New Mexico wildfires using a series of VIIRS Day/Night Band images is available at this blog post.

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