Pyrocumulonimbus clouds created by a wildfire complex in British Columbia
GOES-18 Day Land Cloud Fire RGB (top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.3 µm, bottom left) and Near-Infrared “Vegetation” (0.86 µm) + Fire Power derived product (bottom right) [click to play animated GIF | MP4]
GOES-18 (GOES-West) Day Land Cloud Fire RGB, Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Near-Infrared “Vegetation” (0.86 µm) images with an overlay of the Fire Power derived product (a component of the GOES Fire Detection and Characterization Algorithm FDCA) (above) showed that the Hossitl Creek wildfire complex northeast of Fort Nelson (CYYE) — in far northeastern British Columbia (and far southwestern Northwest Territories) — produced a pair of pyrocumulonimbus (pyroCb) clouds on 05 July 2023. Strong northeasterly winds in the wake of a cold frontal passage likely played a role in the rapid flare-up of ongoing fires (and the subsequent pyroCb development).
The thermal signature of active wildfires along the southern perimeter of the complex was either partially or completely masked by clouds much of the time, but one fire did exhibit 3.9 µm brightness temperatures as hot as 76.1ºC and Fire Power values as high as 1550.7 MW (both occurring at 2010 UTC). The pyroCB clouds exhibited cloud-top 10.3 µm infrared brightness temperatures as cold as -54.54ºC at 0110 UTC — at that same time/location, the CIMSS-derived CLAVR-x Cloud Top Temperature was -58.27ºC, with a corresponding Cloud Top Height of 40,266.81 feet (below).
Cursor sampling of GOES-18 “Clean” Infrared Window (10.3 µm) brightness temperature, CLAVR-x Cloud Top Temperature and CLAVR-x Cloud Top Height (bottom left image panel) [click to enlarge]
In GOES-18 True Color RGB images from the CSPP GeoSphere site (below), shades of tan to light brown helped to identify the smoke-laden anvil of the pyroCb clouds as they merged and drifted southeastward across the British Columbia / Alberta border.
GOES-18 True Color RGB images [click to play MP4 animation]