Pyrocumulonimbus clouds with lightning produced by the Dixie Fire in California

July 19th, 2021 |

GOES-17 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.35 µm, bottom left) and Fire Temperature RGB (bottom right) [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.35 µm, bottom left), and Fire Temperature RGB (bottom right) [click to play animation | MP4]

5-minute GOES-17 (GOES-West) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.35 µm) and Fire Temperature RGB images (above) revealed that the Dixie Fire in northern California produced a pair of pyrocumulonimbus (pyroCb) clouds — denoted by cloud-top 10.35 µm infrared brightness temperatures of -40ºC or colder (shades of blue pixels) — late in the day on 19 July 2021. The first pyroCb formed at 2241 UTC, with the second at 2331 UTC, Maximum surface 3.9 µm brightness temperature sensed with this fire was 138.7ºC — which is the saturation temperature for the ABI Band 7 detectors.

GOES-17 Day Land Cloud Fire RGB images (below) include plots of GLM Flash Extent Density and contours of ProbSevere LightnngCast probability — and show that LightningCast probability exceeded 50% as early as 2241 UTC (the time of the initial pyroCb formation), with the first GLM lightning being detected 40 minutes later at 2321 UTC. LightCast probability first exceeded 75% at 2341 UTC — with GLM Flash Extent Density increasing in coverage and intensity 30 minutes later after 0011 UTC (associated with the second pyroCb anvil as it drifted north-northeastward).

GOES’-17 Day Land Cloud Fire RGB images, with GLM Flash Extent Density and contours of ProbSevere LightningCast probability (credit: John Cintineo, CIMSS) [click to play MP4 animation]

This case demonstrates that LightningCast can clearly help improve wildland fire incident awareness and assessment (and safety).

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