Thunderstorm & Lightning Hazards

Approximately 50 people, on average, are killed by lightning strikes each year and others suffering permanent disabilities, such as severe burns. Thunderstorms and lightning are most likely to develop on hot, humid days. Historically, lightning fatalities have occurred between April and September, with most of the strike events happening in June, July and August.

When Thunder Roars, Go Indoors

If you hear thunder, even a distant rumble, get to a safe place immediately. Thunderstorms always include lightning. Lightning may occur up to 10 miles away from any rainfall.

Ways to Be Struck by Lightning

  • Direct Strike – A person struck directly by lightning becomes a part of the main lightning discharge channel. Most often, direct strikes occur to people who are in open areas.
  • Side Flash – A side flash (also called a side splash) occurs when lightning strikes a taller object near a person and a portion of the current jumps from taller object to the person.
  • Ground Current – When lightning strikes a tree or other object, much of the energy travels outward from the strike in and along the ground surface.
  • Conduction – Lightning can travel long distances in wires or other metal surfaces. Whether inside or outside, anyone in contact with anything connected to metal wires, plumbing or metal surfaces that extend outside is at risk. This includes anything that plugs into an electrical outlet, water faucets and showers, corded phones, and windows and doors.

Monitor the Weather

When working outside:

  • Continuously monitor weather conditions.
  • Watch for darkening clouds and increasing wind speeds.
  • Monitor the internet or weather apps for emergency notifications.

Seek Shelter

When a lightning storm threatens, take these precautions:

  • Seek shelter inside a building whenever possible. Avoid open shelters like pavilions or porches.
  • Once inside, stay away from open windows, sinks, toilets, tubs, showers, appliances, electric boxes and outlets.
  • If you’re in a vehicle, stay there and roll up the windows.

Stuck Outside?

If you’re caught outside, and there is no shelter or no time to seek adequate shelter:

  • Crouch down with your feet close together.
  • Keep your hands on your knees and lower your head.
  • Get as low as possible without touching your hands or knees to the ground, and DO NOT LIE DOWN.

Download the printable PDF and Recording Form here.

Members can download the audio version of this toolbox talk here.

Thunderstorms and Lightening – A Dangerous Duo

Originally published 06/13/2017

Thunderstorms can be very dangerous. The National Weather Service (NWS) issues watches and warnings for severe thunderstorms. A watch means that conditions are favorable for the formation of a severe thunderstorm; a warning means that a severe thunderstorm has been sighted or has been indicated on NWS Doppler radar. Although they can occur at any time, severe thunderstorms are most common between the months of April and August.

Severe thunderstorms are defined by the NWS as storms with downdraft winds in excess of 58 miles an hour. They will also likely produce lightning and/or hail one inch in diameter or greater. A bolt of lightning can carry 30,000 to 500,000 amps of electricity of 15 million to 125 million volts. An average lightning bolt is 3 to 5 miles long and anywhere from 1/2″ to 5” wide.

What you can do before a storm strikes:

  • Know the county you work in and the names of the nearby cities and towns. Severe weather warnings and statements are issued by county and reference major cities.
  • Watch for signs of an approaching thunderstorm, which may include darkening skies, a sudden wind shift and drop in temperature. Keep a battery-powered weather and/or AM/FM radio with you.

When thunderstorms approach, consider doing the following:

  • Remember the 30-30 lightning safety rule: seek safe shelter if, after seeing lightning, you cannot count to 30 before hearing thunder. Even if you don’t see it, if you can hear thunder, you are close enough to a storm to be struck by lightning.
  • Wrap-up, pause or postpone outdoor work. Secure outdoor objects that could blow away or cause damage.
  • Seek safe shelter inside a building or hard-topped vehicle (a car or truck). Heavy construction equipment with a Rollover Protection System, doors and windows is safe, but you should shut down the equipment and close the doors. Sit with your hands in your lap (don’t touch the metal) until the storm ceases. Rubber tires provide no additional protection from lightning; it is the metal vehicle body surrounding you that protects you.
  • Never get out of your vehicle or equipment if lightning is striking close by.
  • Cordless and cellular telephones are safe to use. Use a corded phone only for emergencies.

What you should do during a thunderstorm:

  • If you are caught in the open, find a low area that is not near water. Stay away from trees, fences and water, as they attract lightning. Watch for flash flooding.
  • Remove your tool belt and don’t hold any objects in your hands. Avoid anything metal.
  • Crouch down with only the balls of your feet touching the ground. Do not lie on the ground, as current could flow through you, causing a heart attack, internal injuries and/or burns. Keep your head down and make yourself as small a target as possible.
  • Do not huddle in a group. Stay at least 15 feet away from others.

What to do if someone is struck by lightning:

  • Call 911 for medical assistance as soon as possible.
  • Check the victim’s pulse and breathing. If both pulse and breathing are absent, CPR should be administered at once.
  • If the victim appears only stunned or otherwise unhurt, check for burns, especially at fingers and toes and next to buckles and jewelry.
  • Give first aid for shock and do not let the victim walk around.

Download the recording form here.