![\"GOES-17](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2020\/06\/200611_goes17_visible_shortwaveInfrared_longwaveInfraredWindow_AZ_pyrocb_anim.gif\")
<\/a>GOES-17 \u201cRed\u201d Visible (0.64 \u00b5m, top),<\/em> Shortwave Infrared (3.9 \u00b5m, center)<\/em> and \u201cClean\u201d Infrared Window (10.35<\/em> \u00b5m, bottom)<\/em> images, with hourly plots of surface reports [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>1-minute Mesoscale Domain Sector<\/strong><\/a> GOES-17 (GOES-West)<\/em> \u201cRed\u201d Visible (0.64 \u00b5m<\/strong><\/a>), Shortwave Infrared (3.9 \u00b5m<\/strong><\/a>) and \u201cClean\u201d Infrared Window (10.35 \u00b5m<\/strong><\/a>) images (above)<\/strong> <\/em>showed the formation of a pyrocumulonimbus<\/strong><\/a> (pyroCb) cloud that was spawned by the Bringham Fire<\/strong><\/a> in extreme eastern Arizona during the afternoon hours on 11 June 2020<\/strong><\/a>. To be classified as a pyroCb, the deep convective cloud must be generated by a large\/hot fire, and eventually exhibit cloud-top 10.35 \u00b5m infrared brightness temperatures of -40\u00baC and colder — assuring the heterogeneous nucleation of all supercooled water droplets to form ice crystals. The pyroCb cloud\u00a0then moved northeastward across far western New Mexico.<\/p>\n In Shortwave Infrared imagery, the fire’s thermal anomaly or “hot spot” was depicted by the cluster of red pixels — and the pyroCb cloud tops\u00a0 appear warmer\u00a0(darker gray)<\/em> than those of nearby conventional thunderstorms, due to enhanced reflection of solar radiation off the smaller<\/em> ice crystals found in the pyroCb anvil (reference<\/strong><\/a>).<\/p>\n The pyroCb exhibited minimum cloud-top 10.35 \u00b5m infrared brightness temperature in the -40 to -49\u00baC range (shades of blue) — <\/em>according to rawinsonde data from Tucson, Arizona at 00 UTC on 12 June (below)<\/strong>,<\/em> this roughly corresponded to altitudes of 10-12 km.<\/p>\n Plot of rawinsonde data from Tucson, Arizona [click to enlarge]<\/p><\/div>\n Suomi NPP VIIRS True Color RGB image, with plots of VIIRS Fire Radiative Power [click to enlarge]<\/p><\/div>A Suomi NPP VIIRS True Color Red-Green-Blue (RGB) image viewed using RealEarth<\/strong><\/a> (above)<\/strong><\/em> included plots of VIIRS Fire Radiative Power. The hazy signature of smoke drifting northward was apparent in the image. In fact, a plot of surface observation data at Springerville, Arizona (KJTC) (below)<\/strong><\/em> indicated that surface visibility was eventually reduced to 7 miles around 23 UTC as strong southerly winds advected smoke northward from the fire.<\/p>\n<\/a><\/a>