One of the things we’re most looking forward to is sharing with our readers the knowledge, expertise, wisdom, and general good chi of genuine smart / experienced / good looking folks who have something to share that will improve your fly fishing (and general life) experience.
It is our intent to offer these good folks yet another platform here on Chi Wulff to share their bounty with the rest of us (suggestions for guest posts and topics are most welcome).
The first of these special features covers a topic that is both timely (our first thunderstorms of the season are forecast for the next few days) and poorly understood by most fly fisherfolk we’ve observed over the years – Lightning and Lightning Safety for Fishermen.
The author of this well researched and written three-part series is a new friend we’ve met right here in Bozeman – Dwight Short. Here’s what Dwight offered when we asked to tell a bit about himself -
I’m a retired radiology and nuclear medicine physician who moved to Bozeman from Kentucky 10 years ago. My goal was to live and fly fish in a wonderful environment with family and good friends. I have been blessed beyond measure with success in this quest. I am also blessed to have been able to start my grandsons on a life long journey of fly fishing and fly tying.
Lightning and Lightning Safety for Fishermen (Part 1)
After being caught out in several severe thunderstorms over the past few years and not really knowing what to do to ensure my safety, I decided to do some research on lightning and lightning safety. The statistics are sobering. From 1959 to 1994 the National Weather Service recorded 3,239 deaths from lightning strikes and 9,818 injuries. Due to the vagaries of data collection, these figures most likely represent underreporting of the situation. Most of the people involved in lightning strikes are engaged in outdoor activities: ball players, hikers, golfers, hunters and fishermen. In large part, I am going to address the issue as it pertains to fishermen, but many of the principles are applicable to everyone.
There are many sources of information available on the internet and I have cited the ones that I used at the end of this paper. I did not give them direct attribution within the article, however. As with most scientific articles about our natural world, there are some differences in opinion about some of the topics, but overall the information was remarkable consistent. I would encourage anyone interested in this subject to look at the web sites. They are well done with more detailed information and graphs and are easy to navigate. I want to thank Dave Corcoran of Dave Corcoran Outfitters in Bozeman, MT, for his valuable information and advice in the writing of the on- water safety portion of the article. I am also grateful to Bill Vance of Bozeman, MT, for his review of this article and giving some very wise suggestions.
To begin, what is lightning? The simple definition is that lightning is a gigantic spark of static electricity, similar to, but much larger that the spark created when a person walks across the floor and reaches for a door knob. How lightning forms is not totally known. The leading theory focuses around separation of electrical charges and formation of an electrical field within a thunderstorm. Recent studies indicate that ice, hail and semi-frozen water drops (graupel) are essential elements of lightning development. Thunderstorms are very turbulent environments in which there are strong upward and downward air currents. These currents transport ice, hail and water and the resulting friction between the substances creates electrical charges within clouds. Positive charges are located in the upper portion of the clouds and negative charges are in the lower portion. Because the atmosphere is such a good insulator, 75% or so of lightning in a storm occurs within the cloud itself.
Most of the remaining lightning that strikes the ground is so called negative lightning. A moving thunderstorm gathers a pool of positive charges that move on the ground along with it. As differences in charge continue to increase, the positive charges rise up taller objects such as trees, telephone and power poles, buildings and mountains. When the positive and negative charges become strong enough, lightning bolts develop between the lower portion of the cloud and the ground. Taller objects are usually struck because there is less atmospheric insulation between them and the cloud. However, what is struck depends on where the positive charges accumulate. Lightning may strike the ground even if there are tall trees close by.
A less common form of lightning is called positive lightning. This is lightning that develops between the positive charges in the upper portion of the clouds and negative charges on the ground. Because this lightning must travel further to reach the ground, its electrical field is typically much stronger than of negative lightning. It may be as strong as 300,000amps and one billion volts. This type of lightning may strike ten or more miles from the thunderstorm. This is commonly known as a “bolt from out of the blue” because it often strikes before people on the ground are aware of a thunderstorm approaching them. While typically shooting from the front of an approaching storm, it may come from the sides or back.
Thunder is an acoustic shock wave caused by the extreme heated created by a lightning flash. Lightning may be as hot as 54,000 degrees F. This great heat expands air molecules creating a shock wave similar to a sonic boom. The speed of sound depends on air temperature, but a good workable average is 1000 feet/second or about 1 mile/5 seconds. Thunder can be heard up to ten miles or so.
Tomorrow Dwight offers practical lightning safety tips you can use today on the river…..
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