As we get further into the Merry Month of May, we all rush out and want to play. We garden. We rake. We even get the dock into the lake. In general, we’re outside a whole lot more!
But the problem is that at the very same time we humans burst upon the outdoor scene, M. Nature is gearing up for the start of our thunderstorm season.
So today I want to spend a bit of time talking about thunderstorms and their associated hazards.
First of all, a thunderstorm does not need to be a “Severe Thunderstorm” to be deadly. Flash flooding and lightning are thunderstorm’s most lethal threats, in terms of average annual fatalities, yet neither are part of the definition of a Severe Thunderstorm! More on each of these dangers shortly.
But first, just what is a “Severe Thunderstorm”? It is a thunderstorm that produces damaging winds and/or damaging hail. A given Severe Thunderstorm Warning will always specify the speed of the wind and the size of the hail. But even without knowing those specifics, when you hear “Severe Thunderstorm Warning” it means that storm has winds and/or hail sufficient to do damage.
By the way, if you ever experience damaging weather, please post information about it as soon as possible on the Wall of my Facebook page, facebook.com/tedsweather. Always include both your location and the time that the damage occurred. This provides real, boots-on-the-ground information as to what the storm is doing, and it gives your neighbors in the path of the storm a clear picture of what is heading their way.
Now, earlier I said we’d return to flash floods and lightning, and now we shall. When talking about thunderstorms, there is one thing that surprises just about everyone. In terms of annual lives lost, the most dangerous weapon a thunderstorm has in its arsenal is — water!
Sometimes the rain in thunderstorms is so heavy, water begins to flow over the road. Water is much heavier than people tend to think it is. Weighing in at around 1,700 pounds per cubic yard, when it is moving (flowing water is moving water), it exerts tremendous pressure on whatever it pushes against, and that includes vehicles!
It only takes about shin-deep flowing water to sweep cars, SUVs, and pickups off the road and into a raging stream. The National Weather Service uses the phrase: “Turn around, don’t drown!”, and I think it is very good advice! It might surprise you to know that, on average, flash floods result in more deaths in the USA than lightning. And of those who die in flash floods, 75 percent are in their cars. Death by flash flood outpaces death by lightning strike by a 4-to-1 margin!
When there is flooding, such that creeks or streams are flowing over roads (sometimes washing them out), the NWS Caribou office will issue a “Flash Flood Warning” for the area affected. You can see these right on your smartphone by going to the homepage of the NWS Caribou office, ( www.weather.gov/car/) .On their homepage is a map of Maine, on which the affected area will be identified. Many folks have weather alert apps, but if you are not one of them, that’s where to go to look for all advisories, watches and warnings, at any time of the year. You can also pick up warnings with a weather radio, which I have written about in past columns.
Now, let’s talk about lightning. People tend to focus on lightning fatalities. But many more people than are killed, are struck and live, but sustain life-altering injuries. Lightning is no joke.
Fortunately the safety rules for lightning are really easy to remember!
1) If you can hear thunder, you are right then and there in the lightning threat zone. Suspend outdoor activities at once and seek shelter. 2) Remain safely sheltered for a full 30 minutes after the last thunder has been heard.
By the way, a car with a metal roof is a safe place to be when lightning threatens, due to the body of the car conducting the charge around the occupants, and down into the ground. Contrary to (very) popular belief, it is not because of the rubber tires that a car is safe. If you don’t believe me, google “Faraday cage.”
Oh, I mentioned last time that the date of today’s paper, May 18th, is the 36th anniversary of the eruption of Mt. St. Helens in Washington State. If you have never seen the astounding video of this, go to youtube and check it out.
Ted Shapiro holds the Broadcast Seal of Approval from both the American Meteorological Society and the National Weather Association. An Alexandria, Va. native, he has been chief meteorologist at WAGM-TV since 2006. Email him at tshapiro@wagmtv.com.
