By Vicki Schmidt
From thundersnow to microbursts, severe weather can occur anytime of year. But when it comes to fires, destruction, or death due to lightning, the hot and humid afternoons of summer months are prime time. What makes lightning so deadly? Remember back to grade school science and the basic fact that storm clouds are filled with tons of negatively charged particles that are highly attracted to, and seeking, positively charged ground?
Of the three most common types of lightning, cloud-to-ground, cloud-to-air, and cloud-to-cloud: cloud-to-ground strikes are the better-known and also the most dangerous. While the United States receives between 20 and 25 million cloud-to-ground strikes annually, here in Maine 60,000 strikes a year is the average.
An interesting fact about lighting is that statistically, the chances of you being struck by lighting in any given year are about 1-in 15,300, with a 1-in 1.2 million chance of being killed. In the last decade Maine has seen only two deaths from lighting strikes, both in 2008. Yet the chances that your home will be struck by lighting are an alarming 1 in 200!
Another curiosity is that while we think of lighting as hot, lightning is only the movement of an electrical charge and therefore does not have its own temperature. The heat associated with lightning is the result of atmospheric resistance. Air surrounding lightning heats rapidly to nearly 50,000 degrees Fahrenheit. Almost five times the temperature of the sun! Knowing this makes it easy to understand how lighting can cause fires, even when its raining out.
Lighting strikes can easily cause both wildland and structure fires. The only nonhuman cause of a wildland fire is lightning. According to Maine Forest Service data, lightning causes 4-5 percent of Maine’s wildland fires in an average year. While news reports of lighting causing a home fire make the headlines, structure fires caused by lighting are less common. The Maine Fire Marshals Office notes that 15 (less than 1 percent) of the 3,494 reported structure fires in Maine in 2020 were determined to be caused by a lighting strike.
Structures, especially modern lightweight construction with synthetic components, can be quickly ignited by lighting. If your home is struck you will hear a loud powerful cracking sound that can shake the building. Call 911 and report that your home was struck by lighting. Evacuate everyone and your pets immediately. You may or may not see or smell heat, smoke, or fire, as the potential for fire can be well hidden.
Most fire departments in Maine carry “TICs,” thermal imaging cameras, that can detect hot spots and fires within the walls or ceiling of your home. Potential fire threats can be detected and extinguished before they fully develop and cause extensive damage.
If you hear thunder, realize that lighting is also happening. If you see lighting, but do not hear thunder it means the thunder is too far away or atmospheric conditions are bending the sound waves upward and away from Earth. This phenomena is called “heat lighting” and again, is most often seen in the summer.
While it may seen that severe storms pop out of nowhere, the nature of weather does give us signs if we learn to watch, feel, and listen. Watch for darkening skies and black clouds. Note if you feel changes in temperature or winds that increase and often change direction. Listen for thunder and if you see heat lighting, indicating a storm is in the distance, take it as a clue that a severe storm could be headed in your direction.
— Vicki Schmidt is a Maine state fire instructor and volunteers with the Buckfield Fire Department, as well as several regional and state fire training organizations.
