Lightning in our area has been almost a daily occurrence the last few weeks. This has raised some questions among the community regarding safe places and procedures during a lightning storm. The below lightning safety information has been adapted from NOAA and other sources and explains some of the safety procedures you can take in your home and other protective actions.
Is My Home Safe During Lightning?
A house or other permanent, substantial type structure offers the best protection from lightning. For a shelter to provide protection from lightning, it must contain a mechanism for conducting the electrical current from the point of contact to the ground. These mechanisms may be on the outside of the structure, may be contained within the walls of the structure, or may be a combination of the two.
- On the outside, lightning can travel along the outer shell of the building or may follow metal gutters and downspouts to the ground.
- Inside a structure, lightning can follow conductors such as electrical wiring, plumbing, and telephone to the ground. Unless specifically designed to be lightning safe, small structures do little, if anything, to protect occupants from lightning
Many small open shelters on athletic fields, golf courses, parks, roadside picnic areas, schoolyards and elsewhere are designed to protect people from rain and sun, but not lightning. A shelter that does not contain plumbing or wiring throughout, or some other mechanism for grounding from the roof to the ground is not safe. Small wooden, vinyl, or metal sheds offer little or no protection from lightning and should be avoided during thunderstorms.
There are three main ways lightning enters homes and buildings.
- A direct strike
- Through wires or pipes that extend outside the structure
- Through the ground
Regardless of the method of entrance, once in a structure, the lightning can travel through electrical, phone, plumbing, and radio/television reception systems. Lightning can also travel through any metal wires or bars in concrete walls or flooring. Lightning can travel long distances in both phone and electrical wires, particularly in rural areas.
Stay away from windows and doors as these can provide the path for a direct strike to enter a home. Do not lie on the concrete floor of a garage as it likely contains a wire mesh. In general, basements are a safe place to go during thunderstorms However, there are some things to keep in mind. Avoid contact with concrete walls which may contain metal reinforcing bars. Avoid washers and dryers since they not only have contacts with the plumbing and electrical systems, but also contain an electrical path to the outside through the dryer vent.
Lightning also causes significant damage to personal property each year. In addition to direct strikes, lightning generates electrical surges that can damage electronic equipment some distance from the actual strike. When possible, unplug any appliances or electronic equipment from all conductors well before a thunderstorm threatens. Remember to disconnect televisions or radios from outdoor antennas.
What about cell phones? Are they safe?
Lightning can’t travel through the radio waves associated with your cell phone. As long as the cell phone is not connected to an electrical outlet. There isn’t any evidence that cell phones somehow “attract” lightning.
It can be dangerous to hold a metal object near your skin when you are out in a storm. Skin is a poor conductor of electricity, but put any metal object next to it (cell phone, golf club, ear buds, etc.) and the lightning has an enhanced entrance into the body and the impact is multiplied. If you are outdoors, unplug your iPod from your ears and put the cell phone away.
Is my car safe in a lightning storm?
Most cars are safe from lightning, but it is the metal roof and metal sides that protect you, not the rubber tires. Convertibles, motorcycles, bicycles, open-shelled outdoor recreational vehicles and cars with fiberglass shells offer no protection from lightning. When lightning strikes a vehicle, it goes through the metal frame into the ground. Don’t lean on doors during a thunderstorm.
Summary of lightning safety tips:
- Avoid contact with corded phone.
- Avoid contact with electrical equipment.
- Avoid contact with plumbing.
- Do not wash hands, take a shower, wash dishes or do laundry.
- Stay away from windows and doors and stay off of porches.
- Do not lie on concrete floors and do not lean against concrete walls.