![](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2023\/09\/230922_goes18_dayLandCloudFireRGB_shortwaveInfrared_infraredWindow_visibleFirePower_BC_AB_pyroCbs_anim.gif\")
<\/a>GOES-18 Day Land Cloud Fire RGB (top left), Shortwave Infrared (3.9 \u00b5m, top right), \u201cClean\u201d Infrared Window (10.3 \u00b5m, bottom left) and \u201cRed\u201d Visible (0.64 \u00b5m) + Fire Power derived product (bottom right), from 1750 UTC on 22 September to 0500 UTC on 23 September [click to play animated GIF |\u00a0MP4<\/strong><\/a>]<\/p><\/div>10-minute Full Disk sector GOES-18 (GOES-West)<\/em> Day Land Cloud Fire RGB<\/strong><\/a>, Shortwave Infrared (3.9 \u00b5m<\/strong><\/a>), \u201cClean\u201d Infrared Window (10.3 \u00b5m<\/strong><\/a>) and \u201cRed\u201d Visible (0.64 \u00b5m<\/strong><\/a>) + Fire Power derived product (a component of the GOES Fire Detection and Characterization Algorithm\u00a0FDCA<\/strong><\/a>)\u00a0images\u00a0(above)<\/strong><\/em> showed signatures of multiple wildfires across northeastern British Columbia (BC) and northwestern Alberta (AB), some of which produced numerous \u00a0pyrocumulonimbus<\/strong><\/a> (pyroCb) clouds late in the day on 22 September 2023. Several of these fires burned very hot, exhibiting 3.9 \u00b5m shortwave infrared brightness temperatures of 137.88\u00baC (the saturation temperature of GOES-18 ABI<\/strong><\/a> Band 7 detectors) — and for the large wildfire near Rainbow Lake AB (CWSH), Fire Power values intermittently reached the 6400-6405 MW range (which are the highest GOES Fire Power values sampled by this author for any wildfire).<\/p>\n True Color RGB images from the CSPP GeoSphere<\/strong><\/a> site (below)<\/strong><\/em> displayed the BC\/AB pyroCb development, as well as widespread dense smoke from the many wildfires across the region.<\/p>\n GOES-18 True Color RGB images [click to play MP4 animation]<\/p><\/div>A longer animation of GOES-18 Infrared images covering a larger area (below)<\/strong><\/em> showed that while two of the largest BC fires produced 1 to 4 pyroCb clouds each — pyroCb clouds are defined as having cloud-top 10.3 \u00b5m infrared brightness temperatures of -40\u00baC and colder, shades of blue — one of the two largest AB fires produced an amazing string of 7<\/strong> pyroCb clouds (between 2300 UTC on 22 September and 0800 UTC on 23 September). About 100 miles downstream (northeast) of that prolific pyroCb-producing AB wildfire, smoke reduced the surface visibility to 1\/2 mile for several hours at Hay River (CYHY)<\/strong><\/a> in the Northwest Territories.<\/p>\n GOES-18 “Clean” Infrared Window (10.3 \u00b5m) images, from 2030 UTC on 22 September to 1000 UTC on 23 September [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>The coldest cloud-top 10.3 \u00b5m infrared brightness temperature exhibited by the largest of the AB pyroCbs was -60.6\u00baC — placing it at an altitude near 12 km (just below the tropopause) as seen in a plot of rawinsonde data<\/strong><\/a> from Fort Nelson BC (CYYE) (below)<\/strong><\/em>.<\/p>\n Plot of rawinsonde data from Fort Nelson, British Columbia at 0000 UTC on 23 September [click to enlarge]<\/p><\/div>\n<\/a><\/a><\/a>