Lightning activity level (LAL) is a scale that describes degrees and types of lightning activity. Values are labeled 1–6. This system is no longer used in wildland fire forecasts.
+ Lightning Activity Levels Level Description 1 No thunderstorms 2 Isolated thunderstorms. Lightning is very infrequent, 1–5 cloud-to-ground strikes in a five-minute period. 3 Widely scattered thunderstorms. Lightning is infrequent, 6–10 cloud-to-ground strikes in a five-minute period. 4 Scattered thunderstorms. Lightning is frequent, 11–15 cloud-to-ground strikes in a 5-minute period. 5 Numerous thunderstorms. Lightning is frequent and intense, greater than 15 cloud-to-ground strikes in a five-minute period. 6 Dry lightning (same as LAL 3 but without rain). This type of lightning has the potential for starting fires, and is normally highlighted in fire weather forecasts with a red flag warning.
References
External links "Fire Weather Forecast Variables" from the National Wildfire Coordinating Group