~ National Lightning Safety Institute ~

Section 4.1

NLSI recommends that all organizations prepare a Lightning Safety Plan and inform all personnel of its contents. In a sentence, lightning safety is "anticipating a high-risk situation and moving to a low-risk location." Lightning Safety Plans should be site-specific, but they all share a common outline:

1. Advanced warning of the hazard. Some options:

1.1 "If you can see it, flee it; If you can hear it, clear it."

1.2 TV Weather Channel; NOAA Weather Radio

1.3 Fancy lightning detectors; off-site meteorological services

2. Make decision to suspend activities and notify people.

2.1 The 30/30 Rule says to shut down when lightning is six miles away. Use a "flash to bang" (lightning to thunder) count of five seconds equals one mile (10 = 2 miles; 20 = 4 miles; 30 = 6 miles).

2.2 Notify people via radio, siren or other means.

3. Move to safe location.

3.1 A large permanent building or metal vehicle is best.

3.2 Unsafe places are near metal or water; under trees; on hills; near electrical/electronics equipment.

4. Reassess the hazard.

It’s usually safe after no thunder and no lightning have been observed for thirty minutes. Be conservative here.

5. Inform people to resume activities.