Lightning 101

A late afternoon lightning strike in Kemptville, Ontario. (ValleyWeather Photo)

June 13 -19 is lightning safety week in Canada.

Summer weather means heat and humidity in Montreal, and along with that comes the ever-present risk of thunderstorms. Thunderstorms produce a variety of nasty by-products including hail, high winds, flooding and even tornadoes. However one of the biggest killers during thunderstorms in North America is lightning. On average, a lighting strike occurs every three seconds in Canada during the summer months of June trough August. At any given second, lightning is striking the earth somewhere. Nearly 2000 thunderstorms are active around the earth every minute! Lightning is responsible for numerous deaths and injuries, and significant damage to homes, electrical devices and power grids. Nearly 45 percent of forest fires in Canada are started by lightning.

You should know that there is no safe place outdoors during a thunderstorm; your best defence is to get inside. While your chances of being struck by lightning are statistically slim, in an average year, ten Canadians pay the ultimate price for taking the gamble. Another 150 to 160 are injured, some with injuries that will have lifelong repercussions. The average bolt of lightning contains 300 million volts, enough energy to light a 100-watt incandescent light bulb for about three months. The air displaced by lightning is heated to nearly 28,000C (50,000F), a temperature five times that of the sun and hot enough to melt car tires and burn skin. If you are stuck outside, get as low as you can, make yourself as small as possible.

One of the myths about lightning is that it never strikes the same place twice. The Empire State building in New York City is struck an average of over 100 times each year. Likewise, the CN Tower in Toronto, Ontario is struck several times each year. Lightning likes tall objects. Stay away from trees. Most thunderstorm-related deaths across North America are from those who seek shelter under a tree during a thunderstorm. It is one of the worst places
you can put yourself, another being anywhere on or near water. Head ashore as soon as threatening weather approaches. You should always know the risk of thunderstorms when boating or at the beach. Keep a weatheradio with you at all times. They are inexpensive and could be a lifesaver.  Alternately, you can download one of the weather apps for your smartphone. Environment Canada monitors lightning strikes across Canada, and displays the information at http://weather.gc.ca/lightning/ updated every 10 minutes. Know the risks, plan and prepare to take shelter. This is especially true during outdoor events including baseball, soccer and concerts.

Lightning can strike more than 5km from the parent storm, so as soon as you hear thunder, head indoors. Refrain from outdoor activities such as swimming, soccer or golfing for at least 30 minutes after the last thunder occurs. A recent study by Environment Canada indicated that as little as 3-5% of individuals injured or killed by lightning in Canada are victims of a direct hit. Most hits occur by ground current (40-50%) or side flash (20-30%). That is why it is so important to refrain from using electrical appliances such as phones or computers that are hardwired directly to your home. Cordless items are fine to use.

You are relatively safe inside a car. However, if a car is directly hit, significant damage, including fire and blown out windows can occur. Another popular myth is that people struck by lightning can’t be touched. A person struck by lightning is safe to handle immediately after the hit. They may need CPR or other medical attention. You should call 911 without delay.