When you hear the lightning Protection System alarm you should immediately take shelter in a building or vehicle. Do not call 911 unless you have an emergency. The alarm sound is generally one 15 second long audible blast and is accompanied by a strobe light. The alarm indicates, as an approximate, that there is potential for a lightning strike in the next 8-20 minutes. The area of coverage may vary but generally detections cover from 10-25 square miles.
When you hear three short horn blasts the lightning Protection System is indicating that it's safe to go outside according to its readings. This is the "all-clear" signal. This does not necessarily mean that it's safe outside. Lightning Protection Systems only cover from 10-25 square miles. It has been reported that bolts of lightning can travel 25 miles or more. Also lightning Protection Systems do not warn you about potentially dangerous storm conditions such as hail or tornadoes. You will need to monitor your local weather station and use common sense before going back outside.
Do not wait for the lightning Protection System alarm. It may have malfunctioned. Take shelter immediately. Avoid open ground, parking lots, elevated areas, water, trees, metal fences, power lines, under towers, and any overhead wires.
The best place to take shelter during a lightning storm is within the interior of a large and completely enclosed building that has both plumbing and electrical. Good examples include a home or office building. A barn, storage shed, or other free-standing structure are better than standing out in the open, but will not shield you as well as a structure that has built-in plumbing or electrical systems. This is because electrical systems, wiring, plumbing, and the building's frame, work together to help form a protective shield against lightning. Some refer to this as taking advantage of the Faraday cage effect. In short, this means that a structure will disperse the electrical charge around the exterior, like a cage, generally not harming what exists on the interior. Follow these additional measures to ensure your safety from lightning while inside a building:
» Do not stand near windows. Move to the inner-most rooms within a building if possible.
» Do not touch any metal frame of the structure such as door frames or window frames.
» Do not use any plumbing such as a sink, bath, or shower. These days most pipes are made from plastic, PVC, but may contain water that is conductive. Avoid any pipes and water.
» Stand away from wires such as electrical wires, outlets, cable wires and telephone wires. Stay away from any "wired" device like telephones, appliances, computers, power tools, TVs, and cable TV boxes. Although quite rare, there have been reported cases of lightning injuries and fatalities while using a standard telephone (land-line). However, there is no evidence to support danger using a cell phone or other wireless devices. The handset portion of cordless phone is safe but you should avoid being near the base unit.
Generally yes, but it depends on certain factors. A fiberglass framed car or convertible is not as safe as a sold metal framed car that will take better advantage of the Faraday cage effect. If feasible, seek better shelter only if your car does not appear to have a solid metal frame surrounding you. You also need to roll up the windows of your car and avoid touching any part of the car's metal frame. It's a good idea to keep your hands in your lap until the storm has passed. Of course this does not apply if you are the driver of a moving vehicle. You can seek a safe area to park your car such as at a rest stop. Many people have reported having their car struck by lightning, even while driving, and didn't sustain injury. There is a chance that your vehicle will sustain minor damage to the exterior and to the electrical system.
This is a myth. Even thick rubber tires found on an automobile do not insulate you from lightning. Being completely enclosed, as previously described, helps keep you safe when there's lightning--like a substantial building, home, or solid-framed car. Under no circumstance should you ride a bicycle, motorcycle, or golf cart when there is lightning especially when much safer alternatives exist. The National lightning Safety Institute NLSI provides more information regarding vehicles and lightning.