Lightning discharges that caused forest fires

Of 16 documented lightning discharges 11 caused forest fires in western Montana forests. All 11 discharges exhibited a long-continuing current (LCC) phase of at least 40 msec duration. Of the 5 non-fire discharges, 2 had LCC phases and 3 did not. Results to date strongly support the hypothesis that forest fires are caused by discharges with long-continuing currents. However, available data suggest that discrete discharges (cloud-to-ground discharges without LCC portions) cannot be entirely ruled out as a source of forest fuel ignition.