During the early years of World War II, several ball lightning observations were documented across Europe, including a notable 1939 report coinciding with thunderstorm activity over the continent. Military personnel, trained in observation and reporting, provided some of the most detailed wartime accounts of the phenomenon. Ball lightning was of particular interest to military authorities because it could be confused with enemy ordnance — incendiary devices, signal flares, or experimental weapons — leading to false alarms and wasted defensive resources.
The wartime ball lightning reports are valuable to researchers because military observation protocols ensured systematic documentation of time, location, duration, and behavior, producing records more detailed than typical civilian accounts. Some wartime reports describe ball lightning entering aircraft (both on the ground and in flight), consistent with the phenomenon's documented ability to enter enclosed spaces. The 1939 accounts contributed to growing military awareness that atmospheric electrical phenomena could interfere with operations and equipment, a concern that would intensify as radar technology became widespread.