LETTER:Picton area sees rare ‘Thundersnow’ event Friday

Editor’s note: A reader offers their experience on Friday morning when a rarely seen and heard weather phenomena violently shook parts of Prince Edward County.

Despite some formal training in climate (many years ago), I had never, ever heard of “thundersnow” storms before Friday, Nov. 18! While not comparing Picton to what Buffalo is experiencing, I think we did have a “hit” of this experience early in the morning (about 4:45 a.m if I read the clocks correctly) of Friday.

I was sound asleep at the time. There was a huge flash of light, and a simultaneous crash of thunder, infinitely louder than any I have ever heard in any storm despite having lived on the shore of the Atlantic ocean as a child.

I was – literally – jolted upright, eyes opened! When I pulled myself together and realized the house was not on fire (etc.) I set about re-setting telephones (the lights on some faces were turned on) and the heat which had re-set itself to 60 degrees from 69 degrees. Some other lights on various machines also required adjustment. The power generally was OK – street lights were still on, etc. When I looked out there was about 4” more snow than there had been about midnight, and it was snowing heavily.

When it seemed to settle a bit, I checked the computer and saw that we/Picton were in the midst of a very severe thunder storm. I saw the term “thundersnow” later and thought I should share it.


Mary Lazier Corbett


Wikipedia describes Thundersnow as a kind of thunderstorm with snow falling as the primary precipitation instead of rain. It’s considered a rare and unusual phenomenon. It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone. Thermodynamically, it is not different from any other type of thunderstorm, but the top of the cumulonimbus cloud is usually quite low. In addition to snow, graupel or hail may fall as well. And the heavy snowfall tends to muffle the sound of the thunder so that it sounds more like a low rumble than the loud, sharp bang that you hear during regular thunderstorms. There are usually three causes of thundersnow such as a normal snowstorm that sustains strong vertical mixing which allows for favourable conditions for lightning and thunder to occur. It can also occur from the lake effect or ocean effect thunderstorm which is produced by cold air passing over relatively warm water; this effect commonly produces snow squalls over the Great Lakes.