Geography 101: Thanks to our weather?
Published 11:00 pm Friday, April 12, 2013
Marshall Ramsey, a favorite editorial cartoonist, drew a panel on Thursday and tagged it “How we learn geography in the South.”
The cartoon pictured a man sitting in front of a computer monitor, map in hand, as the reports of a “tornado warning in Yoknapatawpha County” were being broadcast. And, in a response the late William Faulkner could have never imagined, the image went viral on the web within a matter of hours of Ramsey’s posting it to his blog.
I can relate to the message. Moving to Alabama a decade ago, we had to learn a whole new set of county outlines when the weather alerts appeared on the television screens. My sons would pick out Pike County first – “it looks like a puzzle piece” – and then move on to surrounding counties, trying to match names and locations until we learned them all by sight.
So it was no surprise that Ramsey’s cartoon resonated with so many people on Thursday, as a deadly line of storms rolled through Mississippi and into Alabama. We’re weather weary, having been weaned on the watch-and-warning system, trained to prepare for the worst when skies darken on an April afternoon and ready to rally when an unexpected storm brings a tornado on Christmas night.
So what is it about our geography that makes Alabama, and this region of the South, such a target for tornadoes?
According to livescience.com, the United States “is essentially the world capital of tornadoes because of a fluke of geography.” Tornadoes form when warm, moist air is trapped under cool, dry air in supercell thunderstorms. As winds high up travel in a different direction than those a ground level, rotation takes place.
“This setup is common over the central United States in spring when warm Gulf air meets cold Arctic air and the jet stream dips back down over the country after its winter sojourn up north,” says the article. “What can happen in these storms is that rising warm air hits that change in wind direction and begins to rotate like a pinwheel. The heat continues to build underneath the pinwheel until it punches through this “cap” and turns the pinwheel on its side, creating a mass of rotating clouds called a mesocyclone that can spawn a tornado (though they don’t always, and scientists aren’t sure why).”
While the peak time for tornadoes is the spring, there is no defined season. And the incidence of tornadoes seems to shift from south to north from late sprint to midsummer. A second, unofficial season returns in November … and we know all too well that not even holidays are safe from the threat of tornadoes.
The livescience.come article goes on to say that twisters aren’t as well documented in other parts of the world as they are in the United States and are typically only noted when they cause significant damage or happen to be caught on camera, according to the U.S. Storm Prediction Center (SPC), part of the National Oceanic and Atmospheric Administration (NOAA). But the data that is available suggests that outside of the United States,other tornado-prone areas include Canada’s prairie provinces, northeastern Mexico, northern Argentina, southern Brazil, Britain, Bangladesh and parts of southern Russia, according to the SPC.
Of course, we all know that inside the United States, the same geography that makes us Southern and all that we embrace in that also brings all that we loathe and fear in tornadoes and storms.
A sad twist of geographic fate, if ever there was one.
Stacy G. Graning is publisher of The Messenger. She can be reached at firstname.lastname@example.org