Delta Fire pyroCumulonimbus cloud in California
GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Cloud Top Temperature product images displayed using AWIPS (above) showed the formation of a pyroCumulonimbus (pyroCb) cloud generated by the Delta Fire in Northern California late in the day on 05 September 2018. As the pyroCb cloud drifted eastward toward the California/Nevada border, Cloud Top Temperature values cooled to a minimum of -53ºC (lighter green enhancement) at 0300 UTC. Note the pulsing behavior of updrafts over the fire area: 2 distinct updraft pulses were apparent (at 0022 UTC and 0042 UTC), with the later pulse producing the pyroCb.Massive plume of smoke over the #DeltaFire. ?: Jeff Mandrell pic.twitter.com/2QN66HcwM4
— Active NorCal (@ActiveNorCal) September 6, 2018
A longer animation of GOES-16 “Red” Visible, Shortwave Infrared and “Clean” Infrared Window images displayed using McIDAS (below) showed that the first hot (red) Shortwave Infrared pixels appeared at 2027 UTC. The fire caused a 5-mile section of Interstate 5 to be closed. GOES-17 (positioned at 89.5º W longitude during its post-launch checkout phase) had a more direct view of the pyroCb than GOES-16 (positioned over the Atlantic Ocean at 75.2º W longitude) — and GOES-17 “Red” Visible, Shortwave Infrared and “Clean” Infrared Window images are shown below. Unfortunately the default GOES-17 Western US Mesoscale Domain Sector was shifted farther to the south on this day, so 1-minute imagery of the pyroCb event was not available.
* GOES-17 images shown here are preliminary and non-operational *