How long have people stood in awe or cowered in terror as thunderstorms rolled across the land? Seldom have I seen a cow get very worked up over them, but dogs often do. Mine, in particular nearly becomes a basket case long before the fireworks really get under way. Darkening skies and freshening breezes send her scuttling for protective cover.
Well before humans had any inkling of the natural processes involved in storm development, religion and myth combined to produce fanciful beliefs in a gigantic bird whose flapping wings rolled thunder over the western deserts. In the Adirondack Mountains of the eastern U.S., dwarves playing ninepins were believed responsible for the crashing that accompanied storms.
Personally, even though I understand the process, thunderstorms evoke a great measure of excitement and exultation in me. No matter where they perform, their flashing and rumbling is beautiful and awe inspiring to behold.
The most impressive storms I’ve ever experienced were at Grand Canyon where I served as a National Park Service Ranger. In that season when thunder roams the land – July and August – towering cumulus clouds rise from the hot desert lands to the east and the high plateaus north of the Canyon. Usually the storms came in the afternoon, black at their base with brilliant white anvil tops blowing off in the high winds nearly sixty thousand feet in the sky. Often, they arrived with gray curtains of virga (rain that doesn’t reach the ground) streaming down, thunder rolling, reverberating and echoing through the depths of the Canyon’s ancient recesses. Ferde Grofe, the composer, was so impressed with these atmospheric upheavals that he musically painted them into The Grand Canyon Suite. Anyone who has heard that music has experienced the storm in his imagination, and having both heard Grofe’s rendition and witnessed the real thing, I can tell you he captured a Grand Canyon thunderstorm to perfection from start to finish.
As I write this, I am many miles from the Grand Canyon, on the high plains of eastern Colorado, as just such a massive and dangerous storm breaks around me. Yes, I’m thrilled, but also a little worried as I see rotation in the bulging mammatus clouds directly overhead and listen to NOAA radio warn everyone in this small town of Burlington to immediately take cover.
Yet, how lucky we are that our fluid atmosphere surging, rising, and falling across the land maintains the necessary balance of moisture that is essential to life on this planet. So many things happen as thunderstorms develop. The first chill downdraft winds rush through the trees and many of them, for reasons I do not understand, turn their leaves upside down, displaying their pale undersides. Lightning flickers in the distance and gentle rumbles herald the approaching storm.
Thunderstorms storms frequently form along weather fronts and sometimes as “popcorn” squalls from rising thermals caused by the sun’s heating of the land surface. But whether air is forced up at a front or rises because of heating, for every thousand feet of altitude gained, its temperature drops 3-5 degrees, and contained moisture condenses around microscopic nuclei of smoke or chemical particles to form the first cloud puffs that mature into stratospheric monsters that spawn terrible straight-line winds, devastating tornadoes with winds exceeding 300 mph, and hail sometimes up to the size of grapefruit that wreaks havoc as it plummets to earth. Lightning flashes within the growing clouds and from cloud to ground, sometimes with disastrous results. The average lightning bolt produces electrical discharges of 150,000,000 volts and 125,000 amps. Imagine! Darkness seems to well up from the earth, birds flee to secure roosts, and a dead calm may develop in stark contrast to the tumult to come. Icy raindrops the size of nickels spatter the ground, and finally the downpour comes in torrents.
Nevertheless, all things pass, even thunderstorms. The dwarves tire of their bowling, and the thunderbird soars away into the distance. The rain eases, then slows to a sprinkle. Sunlight, refracted through retreating drops, paints that spectacular promise of God’s mercy, a rainbow, sometimes double, across the sky. Birds burst into song and refreshed, all nature seems to take a breath and joyously, life goes on, although this evening’s 4th of July fireworks at the high school were entirely upstaged and replaced by those of the storm.
Dr. Risk is a professor emeritus in the College of Forestry and Agriculture at Stephen F. Austin State University in Nacogdoches, Texas. Content © Paul H. Risk, Ph.D. All rights reserved, except where otherwise noted. Click firstname.lastname@example.org to send questions, comments, or request permission for use.