The Daily Gazette
The Locally Owned Voice Of The Capital Region
Henry Lind's Weather Watch
by Henry Lind

Weather Watch

A Daily Gazette news blog
Weather events in our region and why they happen

The 30 / 30 rule

This is the season for thunderstorms and as one resident commented, “we love watching the light show.” True enough, the light show is spectacular for some, humbling for others, and terrifying for yet a third group. However, thunderstorms are a common event and an interesting statistic is that lightning strikes 25 million times per year in the US.

The awesome power unleashed in a lightning bolt has obvious and sometimes fatal consequence when it strikes the ground. Our safety depends on an understanding of the dynamics of thunderstorms. The 30 / 30 rule has been developed by the National Weather Service to guide our response and is quite simple: if you cannot count to 30 seconds between seeing a flash of lightning and hearing thunder then you are too close — find safe cover because the next bolt could be much closer. Sound travels at about 5 seconds per mile, which translates to about a six-mile range between you and the lightning bolt. The second 30 is to wait at least 30 minutes after the last boom of thunder before leaving your safe cover. This insures that no remnant strikes could be around you after the storm has departed.

This may seem excessively safe but the reality is that lighting strikes can and do occur 10 or more miles away from the center of a thunderstorm and frequently in areas where there is no rain or hail coming down. We’re not about the change the lightning’s behavior. Being prepared means keeping an eye on the forecast and the sky and keeping the 30 / 30 rule in mind.

Enjoy this post? Share it!


There are currently no posts. Be the first to comment on this story.

columnists & blogs