Executive Summary Catalog of National Golf Foundation
February 1995


Countless articles have been written about lightning and its destructive forces. These articles usually refer to various lightning-related facts we can all comprehend. For example, one lightning bolt can generate more than 30 million volts and 250,000 amperes, or that lightning kills an average of 100 people each year and injures 250 more (reported). Obviously, there are many other representations regarding the force and destructive nature of lightning, but these two highlight some basic realities. These statistics, along with other issues, are at the core of the lightning safety passion now encumbering the world of golf.

This summary is not going to deal with the statistical nature of lightning-related incidents, or specific atmospheric measurements. Rather, I'm going to discuss how lightning is generated in the atmosphere, why the voltage/amperage referrals are key to a comprehensive lightning-risk management policy, and what can be done to help each of us avoid the potentially deadly impact lightning can have on ourselves and our friends!

Lightning - A Quick Study

Lightning is basically the result of a massive exchange of electrostatic energy in the atmosphere. Positive ions in the earth become connected to negative ions in the atmosphere and begin exchanging or dumping huge amounts of energy. Of course, there are other natural forces that must be considered such as the resistance of the air between the ground and the storm clouds (the atmosphere is a wonderful insulator). Are you beginning to recognize all the references to things taught in electricity class? In simple terms, lightning involves voltage, resistance, amperage, heat and noise.

A basic way to look at the earth's electrostatic field is by using common car batteries on a grand scale. As we all know, a battery has a positive post and a negative post. In the atmosphere on a storm-free day, we have a low number of positive and negative charges distributed in the ground and in the atmosphere. It is the action of wind and water during the formation of a storm which redistributes these charges to such a degree that we will have mostly positive charges in the ground, mostly negative charges in the overhead clouds, and mostly positive charges in the upper reaches of the thunderheads we often can see during thunderstorms.

If we take the positive terminal of battery one, attach a jumper cable and place it on the ground, we have a representation of ground charge during a storm, only far less powerful. Let's now take a second battery, attach another jumper cable to only the negative terminal, we have the basic negative energy collected in a storm cloud. We are now ready to demonstrate the dynamics of lightning.

Our two jumper cables represent "streamers" which constantly seek each other during storms. These streamers can be quite long, searching for an adequate conductive path ahead of, under or behind the actual storm itself. If we take a cable in each hand and hold them five or six feet apart, we see nothing at all happening. However, there is a slight amount of current flowing between the cables, and that energy can be measured! Now, move your two cables towards one another to a point where they are only six inches apart. Still, you can't see anything, yet the current/voltage has increased considerably and, again, is measurable. (Keep in mind that these ore only 12 volt batteries and you are the guiding factor needed to conduct this experiment. In a real storm, you have millions of volts, which are powerful enough to guide themselves!) Now, if you bring the damps of the two jumper cables together, you will get a strong spark (lightning), and have some difficulty pulling the two cables apart! You have actually created a 12 volt lightning discharge and can clearly see the flash, sense the resulting heat and hear the very mild thunder! In real lightning, most of the atmosphere's energy in that area would have been depleted with the lightning (or spark), and the attraction process would begin again elsewhere. This is a simple but accurate way to understand lightning!

Detection vs. Prediction

In this experiment, we have created a model demonstrating the difference between lightning detection and lightning prediction. Detection systems are prevalent today, examples being radar, sonar, electric eyes, cameras, doppler radar, and the national lightning detection network. This equipment is wonderful in revealing what is happening now or what has already happened. Just as with your battery cables, the only time you knew anything was occurring was at the moment of the spark. By then, you already saw and heard it. That is how all detection systems work. They can show where and when some incident occurred, but it takes other forecasting equipment and guesswork to attempt to advise you where it may move to (or strike) next. In terms of lightning detection equipment, the assumption is made that all the lightning will remain in the approximate area where the lightning is present, often under the storm clouds. The problem with this assumption is that lightning often travels many miles away from the storm, or may be the very first strike from that storm. In these situations, there is not a piece of detection equipment on the face of the earth that will warn you in time to take shelter! These strikes are frequent and usually the killers largely because they are unexpected! Lightning detection equipment monitors the electromagnetic field, which is disturbed as the column of air explodes when lightning occurs. Other less sophisticated systems monitors light flashes in the clouds. In either case, detection equipment tells you little more than you already know by the sound of thunder or the flash of lightning. Obviously, this also clearly explains why thunder is Ml a good or reliable warning. If it is a first strike situation or a bolt from a distant storm, detection is of no value for safety or avoidance.

With this knowledge, prediction makes logical and practical sense. If you think back to our battery cable example of lightning, imagine having a sensitive voltmeter, which can measure the electrostatic field changes between the cables. As the cables moved closer to one another, the voltmeter would show a larger "charge". This level would rise or fall in a direct relation to the proximity of the two cables. At some point in this 12 volt system, you can't stop the cables from coming in contact with one another because the low voltage attractions of positive and negative ions create a strong attraction. In a storm where millions of volts are concerned, the attraction also occurs, but the streamers are much further apart. If a device could accurately measure these ever increasing attractions between streamers, and determine when the field will collapse and form a lightning discharge, then you would be able to provide an early warning … or lightning prediction.

One system that has been predicting lightning for over 20 years is marketed under the trade name of THOR GUARD.' This advanced computer system measures these changes in the earth's electrostatic field and analyzes the likelihood of lightning occurring based on a detailed historical database of actual lightning measurements. By monitoring the earth's electrostatic field in two different and adjustable radii, each and every club receives a customized and accurate analysis of their own property. By taking into account many variables in each of these radii, THOR GUARD will advise the club to discontinue play only when lightning win hit the golf course… not when it misses by a few miles. The net effect is that this system can give a warning in advance of lightning occurring at your golf course, whether or not lightning is occurring anywhere else. When used as an instrument to analyze the lightning hazard in your area, THOR GUARD can make all the difference in the world to expedite clearing the course prior to detectable lightning occurring.

Risk Management Policy and Practices

A mistake many purchasers of lightning warning equipment make is that they assume the system chosen will automatically guarantee the safety of everyone at the club. Nothing could be further from the truth. It is mandatory that a lightning policy be developed that all members, guests, and employees know, accept, and understand. The following suggestions are made to help get you started:

- Place policy instruction placards where everyone can easily observe them.
- Stress the importance of evacuating all outdoor areas immediately when the initial warning is provided.
- Try to advise all individuals to seek shelter in major buildings first, then shelters only in emergency situations.
- If no lightning prediction or detection system is available, return to the clubhouse at the first sound of thunder ... no matter how distant.
- If your hair stands on end when outside, immediately seek shelter or drop to your knees, hands on knees and head down.
- Always error on the side of caution ... a mistake could be tragic.

If you haven't already done so, you can take your understanding of lightning and develop a policy perhaps along these guidelines which will help the club operate more safely. As a side benefit, you will educate members and employees to respond more carefully when they are away from your premises. There are many good sources for safety measures such as the USGA, St. Paul Insurance, Tournament Players Clubs, and the Lightning Protection Institute. Investigate all possible sources for such information and create a program, which can be used consistently and simply as the basis for a comprehensive risk management plan.

*This article was written at the request of the National Golf Foundation for inclusion in their Executive Summary Catalog. February 1995.

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