[BC] 30/30 Lightning safety rule.

[Mike McCarthy]

While on the subject of storm safety, Dr Mary-Ann Cooper, a leading 
researcher and treating physician for lighting strikes and electrical shock 
injuries at the University of Chicago has crafted the 30/30 rule for 
lightning safety.

Its is...two parts

You should seek shelter in a safe location if the thunder from an 
approaching or near-by storm arrives within 30 seconds of a lightning flas; and

As the storm departs, remain in a safe location until 30 minutes after the 
last indication of thunder has elapsed.

This only applies to ground based activities. Of course, when dealing with 
elevated structures and work on towers, the time period should be expanded 
by at least double.  It's not uncommon to see lightning reach out many 
miles from a parent storm and strike taller objects.

As one who has been on a tower as a fast approaching storm struck, I 
realize it hard to visually watch the skies and react accordingly when the 
storm sneaks up on the site.  Hence the need to monitor the WX if there is 
a risk for storm activity.

MM