Fire-generated thunderstorms, known as pyrocumulonimbus, make wildfires more…

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What we can confirm

Authoritative meteorological and wildfire science sources consistently describe pyrocumulonimbus (pyroCb) clouds as a form of fire-generated thunderstorm that intensifies and complicates wildfire behavior, leading to faster spread, greater unpredictability, and higher risks to life and property.[1][2][4][8][11][13][14] Peer‑reviewed research and case studies link pyroCb events with extreme, erratic fire behavior, long‑range ember spotting, lightning-ignited new fires, and violent downdrafts and winds, all of which make wildfires more hazardous and have been associated with high fatality incidents such as Australia’s 2009 Black Saturday fires and Portugal’s 2017 Pedrógão Grande fires.[4][11][13][14] Major news and science outlets summarizing expert views state that these fire-generated thunderstorms can exacerbate fires, make them more intense and unpredictable, and thereby worsen wildfire impacts and risks, meaning they do make wildfires more deadly overall.[1][2][5][6][10][12]

Sources

Checked July 29, 2026