By Dr. Melvin Dace, Chip Howard, Greg McGarity, Adrian Melendez, Chris Patrick, Matt Walser, and Dr. Martin Uman
Melvin Dace, MD, FACP, is Chief of Stadium Medical Operations, Chip Howard is Assistant Athletic Director for Auxiliary Services, Greg McGarity is an Associate Athletic Director, Adrian Melendez, ATC, is Head Football Athletic Trainer, Chris Patrick, ATC, is Assistant Athletic Director for Sports Health, Matt Walser, ATC, is Associate Head Football Athletic Trainer, and Martin Uman, PhD, is Professor of Electrical and Computer Engineering at the University of Florida.
Training & Conditioning, 13.6, September 2003, http://www.momentummedia.com/articles/tc/tc1306/stormwarning.htm
At approximately 6:00 p.m. on Sept. 14, 2002, more than 84,000 football fans watched as the University of Florida played Ohio University at Ben Hill Griffin Stadium in Gainesville, Fla. But one man inside the stadium, Keith Rambo, an electrical engineering professor who monitors severe weather during the Gatorsí home football games, had his attention focused elsewhere.
Rambo was watching his computer screen. Doppler radar showed a band of thunderstorms approaching the stadium from the west, and Rambo was tracking their approach using resources on the Internet. Once the storms moved within 10 miles of the stadium, game operations personnel were notified and passed word to the officials. At 6:20 p.m., Ramboís screen showed a lightning strike six miles from the stadium. As required by Southeastern Conference policy, the referee and head coaches were informed that a large cell of thunderstorms with lightning strikes was within six miles and heading northeast toward them.
At 6:21 p.m., the officials stopped the game and sent the teams to their locker rooms. Fans were informed that the game had been suspended due to severe weather in the area. They were also told that if they wanted to leave and seek shelter, they would be re-admitted with their ticket stubs. After a 46-minute delay, the lightning had moved outside the six-mile radius and play resumed without any further delays. Thanks to the early and accurate warnings, participants and fans were protected and disruption was minimized.
Most athletic departments around the country are aware of the danger that lightning presents to both players and spectators. Lightning safety guidelines were added to the NCAA Sports Medicine Handbook in 1997 and the National Athletic Trainersí Association Position Statement on Lightning Safety, issued in 2000, has also provided valuable guidance. But at the University of Florida, we feel that these guidelines may not go far enough in light of recent technological advances.
The traditional method of assessing the threat from lightning utilizes the flash-to-bang method, where a person counts the time between the lightning and thunder. By dividing the elapsed time by five, an observer can estimate his or her distance from the lightning strike in miles. If the lightning and thunder are 30 seconds apart, for example, that means that lightning struck six miles away and everyone should seek shelter.
However, this method has several limitations. Flash-to-bang fails in active thunderstorms because flashes occur so frequently they create overlapping thunder, making it impossible to determine which flash of lightning caused a particular clap of thunder. Further, the observer may be located where lightning is hard to see or thunder is hard to hear, such as in the press box of a large football stadium or a practice field in a valley with limited sight lines.
Finally, even when the flash-to-bang method does work, it provides information only on the distance between the observer and the lightning strike with no indication of the stormís speed or direction. This creates difficulties in two ways. First, strong storms can move at 40 miles per hour or more and cover six miles in less than 10 minutes, leaving little time for large groups of people to take cover. Second, lightning may be seven or eight miles away, but moving away from the facility, meaning there is no reason to head for shelter.
Therefore, over the past year at the University of Florida, we have been using a real-time lightning detection system. We have found that it provides more safety and protection than other methods for detecting dangerous lightning situations. It is also relatively inexpensive and easy to operate, and we have had few, if any, false alarms with this system. Even the NCAA was impressed enough with our system, after seeing it in action during the 2002 baseball regionals in Gainesville, that it was recommended for use for all baseball playoff sites in 2003.
The system, from Vaisala GAI (lightningstorm.com), allows us to see, in real time, where lightning is striking and anticipate when it will reach us. Built on data from the North American Lightning Detection Network (NALDN), the program tracks lightning strikes throughout the United States and Canada using a network of 106 lightning sensors that record about 90 percent of all cloud-to-ground lightning strikes. We access the data through two Vaisala systems, both of which we connect to through the Web.
The first system shows lightning activity across the United States with the ability to zoom into regional maps or a personal map centered on a specific location. The maps are updated once a minute and provide very specific information. In addition, optional e-mail notifications can be sent to pagers, cell phones, or computers whenever lightning enters or clears a predefined personal area.
Using the second program, we can watch a stormís progress in real time, with lightning strikes usually showing up on the screen within seconds. Data from the previous six hours can be downloaded to examine a stormís history, although we usually look at just an hourís worth of data upon login to help determine the path of any dangerous storms.
Versions of this system have been used by government agencies and utility companies for more than 25 years. It is the only system we know of that provides true reports of where lightning strikes in nearly real time.
The cost of the system varies depending on the features you choose. We paid about $1,250 in subscription fees for the 2002-03 school year. There are monthly and daily fee options available on parts of the system.
Both our operations and athletic training staffs have been trained by experts in our universityís lightning research center on how to best use this system. The training lasted about half a day and provided information about lightning and its dangers, as well as hints for extrapolating future storm movements based on their history. We now train new staff members ourselves rather than sending them to lightning experts. Those without weather experts close at hand can also receive training from Vaisala.
Along with the Vaisala system, we also use the services of the National Weather Service. We regularly call the weather service in Jacksonville to get their interpretation of a storm and use their Web site (www.weather.gov), which includes a fairly current weather radar. Two other helpful Web sites are the Weather Channel (www.weather.com) and Intellicast (www.intellicast.com).
We now use the Vaisala system on a daily basis. Our procedure calls for the athletic trainer to check the system before heading out to the practice fields. This usually takes less than five minutes and may include a quick phone call to the weather service office to check on the potential for severe weather to develop later.
Most of our fields are close to the main athletic offices, so someone can monitor the weather from the athletic training room and still be within a few hundred yards of the practice area. Our two remote facilities, for softball and soccer, have a training room with data hookups that the athletic trainers can use.
Once lightning is detected within a 20-mile radius of our facilities, operations and athletic training staff are automatically notified by e-mail. For teams out on the field, the athletic trainer will let the head coach know where the lightning is. If the lightning comes within six miles, and is moving our way, the athletic trainer notifies the head coach of imminent severe weather and the need to seek shelter. The coaches will actually be the ones to halt practice, but they have all been very receptive to the new proceduresóif they ask, we can show them on our computer screen exactly where the lightning is at any point in time.
The system has also helped cut down on false alarms since we can see both the location of the lightning and its movement. In the past, we may have called teams in because we heard thunder and saw dark clouds to the west, but now we can tell when those are going to stay safely in the distance and pass us by.
The process is a little different for games and varies depending on the sport. Beginning two hours before kickoff of all home football games, we have a member of our universityís lightning research team on site who is especially adept at reading and interpreting lightning data. Upon his arrival, he begins monitoring any severe weather from the press box. One hour prior to the game, inclement weather outlooks and procedures are discussed with game officials. If lightning is detected within 10 miles, the game manager is notified, and in turn notifies the officials. If a lightning strike occurs within six miles of the field, the head referee is again alerted so he can follow the SECís inclement weather policy.
In other sports, the athletic department operations staff will monitor the Lightningstorm.com site and inform the officials about approaching severe weather, including lightning strikes within six miles. The officials will then determine when the game is suspended.
The best time to decide on a severe weather policy is when the sun is shining, not when a storm is brewing. We strongly recommend that every athletic department develop a written lightning safety policy. We also recommend the use of NALDN data.
Every game and practice has a different need and solution. These solutions should be determined in advance and put into writing as part of the overall emergency care plan for student-athletes. Similarly, each athletic departmentís needs are different and your plan must reflect these differences. Smaller schools wonít have the luxury of dedicated lightning experts on hand to watch over a game. But simply using the programís auto-notification system, which can call a coachís cell phone when lightning is detected within a pre-set distance, will provide some protection. Having someone then monitor the real-time data will add another layer of protection. And once the plan has been established, it should be reviewed and revised regularly by the head athletic trainer and other responsible staff members.
At many schools, you as the athletic trainer already monitor weather conditions and can simply add this system to your weather tool box. If you do not perform this function as part of your job, the best solution may be to work with your athletic director to appoint one or two people to be department weather watchers.
These may be people with a natural interest in the weather or computers or may simply be reliable employees. And donít hesitate to make use of other resources at your school. Many colleges offer meteorology classes, and science teachers can be a good resource for high school administrators.
Itís also helpful to talk about your severe weather plans with colleagues at other schools in your league. Severe weather is a regular topic of discussion at the SECís annual game managersí meetings and having all the conference schools follow the same policy makes things easier on everyone.
IF LIGHTNING STRIKES
Unfortunately, lightning is quite unpredictable and there is no way to guarantee that you are completely immune to a lightning strike. Thus our lightning safety protocol also provides for the use of automated external defibrillators (AEDs) in the case of ventricular fibrillation from lightning.
Much is still unknown about the mechanisms of cardiac arrest in lightning injuries, but it is known that lightning can cause disruption to the heart similar to a heart attack. Ventricular fibrillation or asystole (cardiac standstill) in lightning injuries may be a direct result of lightning on the heart or an indirect result of respiratory arrest with anoxia (lack of oxygen). Either way, reviving the patient is almost impossible without an AED.
Spontaneous (without the use of a defibrillator) reversion of ventricular fibrillation to normal rhythm is essentially unheard of in adult cardiology. Any spontaneous recovery from cardiac arrest through CPR is most likely due to the patient being in respiratory, not cardiac, arrest. Lightning injury can cause severe peripheral vasoconstriction making palpation of the peripheral arteries futile for changing cardiac activity.
Under ideal circumstances, CPR produces 25 percent of normal cardiac output, but only 10 percent of the pre-arrest myocardial blood flow. The coronary blood flow necessary for return of spontaneous circulation is 20 milliliters mercury and in CPR the maximum obtained is 10 milliliters mercury. Thus CPR is only buying a little time to defibrillation.
As a result, we feel strongly that AEDs ought to be placed on all suspected cardiac arrest patients, including those with lightning injury. (By the way, there is no risk of shock from touching the victim of a lightning strike.) In cases of cardiac arrest, early defibrillation is one of the most important links to survival. The survival rate in ventricular fibrillation is directly related to the time to defibrillation.
Defibrillation at two minutes is better than six minutes and infinitely better than 10 minutes, where survival rates are practically nil. The window of opportunity is small and essentially requires a defibrillator be in close proximity for success, so we have an AED at all practices and competitions here at the University of Florida.
Itís important to remember that the lightning detection system helps you see what would otherwise be unseen, but it doesnít replace the eyes and ears of people on the scene. The system does not report cloud-to-cloud lightning and some ground strokes (about 10-15 percent) may be missed. In addition, the first bolt of lightning from a storm is as dangerous as the last, but it canít be as easily anticipated. If the skies above turn dark and threatening, use common sense in addition to the data.
There are no guarantees when it comes to lightning. But there are ways to tilt the odds in your favor, and we feel that ours is the best.
Hereís a short explanation of some common weather bulletins for those covering sporting events.
SEVERE THUNDERSTORM WATCH
This is the kind of weather that can produce a severe thunderstorm, defined as having wind gusts of 58 miles per hour or higher, or hail at least 3/4-inch in diameter. These are usually issued for wide areas covering hundreds of miles and may last several hours. Even if the weather is fair, you should monitor the weather closely and be ready to react to severe storms, which may develop quickly.
SEVERE THUNDERSTORM WARNING
This means a severe thunderstorm has been spotted either by a weather spotter or strong evidence from radar. These are usually issued for small areas and last for up to an hour. During a severe thunderstorm warning, everyone should immediately seek shelter.
When a tornado watch is issued, conditions are favorable for the development of storms that can produce tornadoes. Like severe thunderstorm watches, these usually cover wide areas and last for hours. Itís also important to know that areas under a tornado watch are at a higher risk for severe thunderstorms than those under a severe thunderstorm watch. Even if the current weather is good, you should keep a close eye on the conditions and monitor local media or weather radio for any developments.
This means a tornado has either been reported by a weather spotter or indicated by strong evidence from radar returns. These are usually issued for small areas and last for up to an hour. During a tornado warning, everyone should immediately seek shelter.
For more information on severe weather safety, including details on safe shelters during storms, go to www.weather.gov/om/severeweather/index.shtml