Thunder

February 25, 2022

We have been trapped inside by the ice storm that descended on our state on Wednesday.  We received a heavy layer of ice that was repeated throughout the day on Thursday.  Melissa has her home office set up in our Bay window in the kitchen and watched as the few cars and trucks that tried to brave the storm slid into the ditch trying to make a turn.  Since I do most of my work from home, I do not normally get out every day, but being confined by the storm somehow made it feel different.  I was in my office yesterday when I heard thunder amid the sleet falling in the storm.  While most thunder is associated with rain, I have rarely heard it during snowstorms.  This was the first I recall hearing thunder during a sleet storm, but sleet is just short of snow.    

When I looked online, I found thundersnow, or a winter thunderstorm, is an unusual kind of thunderstorm with snow falling instead of rain.  Thermodynamically, it is not any different from other thunderstorms, but the top of the cumulonimbus cloud is usually quite low.  In addition to snow, graupel (snow pellets or corn snow) or hail may fall.  It is unlikely to see lightning during a thunder snowstorm.  First, you must be in the right place when a rare thunder snow happens.  It is estimated that only six snow thunder events occur in the US each year.  Second, in most cases it is not possible to see the lightning because the snow already makes the sky bright and white.  You may hear a rumble of thunder, but the significant snow associated with these storms will muffle the sound.  Typically, the thunder can only be heard within a couple of miles.

The cause of thunder has been the subject of speculation and scientific inquiry for centuries.  Early explanation was it was made by the gods, but the ancient Greek philosophers attributed it to natural causes, such as wind striking clouds (Anaximander, Aristotle) and movement of air within clouds (Democritus).  The Roman philosopher Lucretius held it was from the sound of hail colliding within clouds.  In the mid-19th century, the accepted theory was that lightning produced a vacuum and the collapse of that vacuum produced the sound known as thunder.  In the 20th century a consensus evolved that thunder begins as a shock wave due to sudden thermal expansion of the plasma in the lightning channel.  Experimental studies of simulated lightning have produced results largely consistent with this model, although there is continued debate about the precise physical mechanisms of the process.  I am always happy to hear the thunder, as it is the lighting strike that proceeds the thunder that will kill you.

THOUGHTS:  I faced another bout with winter thunder in Utah years ago.  We were skiing and made the last lift to the summit before it closed due to wind.  The fog and light snow caused the visibility to be about 30 yards, and this was a Blue run I had never skied.  As I dropped below the fog, I realized I was skiing into a bowl with a dense line of trees on the far side.  I cut too close to a tree and a powder drift exploded around my fall.  In that instant, lightning struck, lighting the sky around me, followed by a loud boom of thunder, and then silence.  My thought was, “If this is the Rapture, why am I still here?”  While the noise of thunder may be frightening, it rarely causes permanent damage.  Too bad the same cannot be said for the noise that comes from politicians.  Do the work.  Change is coming and it starts with you.