Monday, 12 January 2009
Last Minute Outdoor Lightning Risk Reduction—A Method To Estimate Its Effectiveness And Comments On Its Utility In Public Education
Hall 5 (Phoenix Convention Center)
Last minute notice outdoor lightning risk reduction was extensively discussed in the lightning safety community during 2006 and 2007, especially in the working group for the National Weather Service annual lightning safety awareness week in the United States and the board of directors for StruckByLightning.Org, a non-profit organization for lightning safety education. Short notice outdoor lightning risk reduction consists of rushing away from the riskiest locations to the safest place available when thunderstorms threaten, spreading out if in a group, using the ‘lightning crouch' if you detect the signs that lightning is about to strike, and then continue fleeing to the safest location available. The ‘lightning crouch' consists of putting your feet together, squatting, tucking your head, and covering your ears. It is meant to be used for only a few seconds just before a potential lightning strike. These procedures are an attempt at risk reduction and do not provide safety since no place outside is safe when thunderstorms are in the area. Last minute notice outdoor lightning risk reduction should be used only as a desperate last resort. You would be much safer by avoiding the situations where the outdoor lightning risk reduction might be used.
This paper will have two main parts. The first part of the paper will estimate the overall effectiveness of last minute outdoor lightning risk reduction by estimating the risk reduction for each of the five main mechanisms of lightning casualties and weighting that risk reduction by the relative frequency of those mechanisms. The five mechanisms of lightning casualties are: 1) direct strike, 2) contact voltage, 3) side flash, 4) step voltage and ground streamer, and 5) upward streamer. The second part of the paper will summarize the arguments for teaching and not teaching last minute outdoor lightning risk reduction. The overall recommendation is that it nor be taught to the general public, though it may be appropriate for groups that spend time in remote locations.