Kevin Myatt is The Roanoke Times' weather columnist.

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An example of a hook echo

Many of you have read "The Perfect Storm," seen the movie, or at least heard about the 1991 event when three systems merged into one and created a storm for the ages over the North Atlantic.

A perfect storm on a much smaller scale came together in the Mississippi River Valley on Sunday night. It was a supercell thunderstorm with an almost flawless radar signature, dropping a series of tornadoes in northeast Arkansas, southeast Missouri and northwest Tennessee.

As a cold front pushed out of the Plains toward the Mississippi River, the relatively cool, dry air behind it encountered warm, moist air ahead of it. To the north, in Missouri and Illinois, a wall of thunderstorms developed, wreaking some degree of havoc, including a few tornadoes.

Farther south, the storms had a harder time developing, as a warm layer of air aloft didn't allow clouds to push upward as quickly. This layer preventing convection is known as a "cap," and often keeps storms from developing even when everything else is favorable for them.

But on this day, the thick cap only served to make sure things would get extra heated. Like a boiling pot, the moist air under the cap began bubbling upward in the afternoon sun, and finally blew the lid off. Massive cumulonimbus clouds towered nearly 12 miles up -- but not everywhere, only in a couple of places.

Two lonely storms, one in central Arkansas just north of Little Rock, one more than 100 miles north in the Ozarks near the Missouri line, exploded into the sky. Strong upper-level winds, moving in different directions with height, began spinning these two storms, ensuring that they would stay separated and not link with other storms to form a line.

In time, the spin in these storms would reach all the way to the surface, spawning destructive tornadoes. The one to the north, moving across northern Arkansas, would become a particularly impressive beast -- a long-track supercell, maintaining a rotation near ground level for hours, steadily marching eastward without losing intensity as it ripped communities in Arkansas, Missouri and Tennessee, killing more than 20 people.

You've probably heard the term "hook echo" before, but you may not have seen one. That's why I pulled out this radar image of the supercell over west Tennessee, to show vividly what is meant by the term. You can see a storm with lots of bright colors, indicating heavy rain and large hail, wrapped into a curl or "hook" on its lower left side, or to the southwest.

The hook shows where the storm is literally being curled around a powerful rotating updraft, which often includes a tornado as the rotation reaches to the ground. This powerful spinning rotation feeds the storm, and the downdrafts crash down around and away from the updrafts, slinging torrents of rain, gusts of wind, and hail large enough to dent cars and houses.

In a supercell, unlike the short-lived "pulse" storms more common here in summer, the updraft is one place, the downdraft elsewhere, and the two do not interfere with each other. This one kept rolling like a well-oiled machine from midafternoon well into the evening.

This particular storm spawned its own swirl of mixed emotions for me as I followed it on radar Sunday night, then read accounts of it afterward.

First, I was deeply saddened as I heard about the destruction wreaked in communities I'm intimately familiar with from my days growing up in the area. I once covered high school baseball and basketball games in Marmaduke, Ark., which was almost obliterated in the storm, with scores of people injured. The death toll in Tennessee is truly heartbreaking.

Secondly, I was thankful that my parents, living in Jonesboro, Ark., 30 miles to the south of the storm's path, were not affected. They were between the two big storms, and didn't even see a drop of rain. Dealing with tornadoes is just part of life there, and we've watched many go north, south, east and west over the years ... and a few get dangerously close.

But finally, there is an awe that takes hold, a wonder, that burrows deep inside contemplating storms of this magnitude. How meager my existence seems against the power exhibited in a single supercell. I am not even a bubble of foam in God's ocean.

And in this case, there was a realization that had I been home visiting my parents at the right time, I would have been in position to chase and photograph the storm of a lifetime.