Lightning is the dominant natural ignition source for wildfire, and its worst form is the dry thunderstorm: a storm whose rain falls into a deep, dry sub-cloud layer and evaporates before landing, seen as virga. The result is lightning without wetting, plus strong evaporatively cooled downdrafts that produce erratic surface outflow winds. A single outbreak can start hundreds of fires across a region in a day, saturating any detection and response system at once. Many strikes produce a holdover fire: the strike smoulders in duff or a snag for hours or days, so ignitions can appear well after the storm has cleared, which breaks the assumption that detection follows shortly after the cause. Lightning location networks report strike position, time and polarity, which is how holdover fires are later matched to their strikes. The confusion this resolves is assuming a thunderstorm reduces fire risk. After this Concept you can explain why a passing storm can leave a region with many simultaneous fires and more still to appear.
Virga is the meteorological phenomenon in which precipitation falling from a cloud base evaporates before reaching the ground, occurring because the air layer beneath the cloud is sufficiently dry to…