By Dr. Robert Thorson
Connecticut was lucky on Wednesday night, and then lucky again. The east-west bullet of tornado destruction merely grazed the top of our state, and wind damage was restricted to its woodsy, rural towns. In southern Massachusetts, however, several tornadoes lined up between Westfield and Sturbridge, taking direct hits on downtown Springfield and Monson. We were spared by a quirk of fate, and nothing more.
“Devastation” was the headline of Thursday’s Hartford Courant. Below that were two dramatic photos. In Springfield, heavy brick buildings were literally blown apart. In Monson, the structure of a Unitarian church made of cut granite blocks survived, but everything made of lighter stuff – roof, windows, yard – looks destroyed.
After an initial groan of sympathy, the story of the “Three Little Pigs” swirled up from childhood memory. The prudent pig was fine because he built his home with bricks, rather than sticks or straw. On Wednesday night, however, not even he could withstand the huffing and puffing of the wolf in tornado clothing. Bricks tumbled. Stone sundered.
Have we entered a different era? Do such old stories no longer apply? My instinct says yes. The facts say it’s too early to tell.
More specifically: Was the degree of damage something new to New England?
No! Tornadoes – and their oceanic equivalents, waterspouts – have always been part of our environmental history. Within my own lifetime came the Worcester Twister, which killed 94 people in 1953. In Connecticut, a tornado scored a line between Windsor to Suffield in 1979, causing three casualties and more than $400 million in damage. Over the long term, our background rate is roughly one tornado and one related death per year. This is low enough for most residents to think of them like airline disasters – something that happens to someone else, someplace else. And so far, they’ve mostly been rural enough to cause relatively little economic impact.
Jumping in scale is another question: Is this year’s tornado season part of something new at the national level? The jury is still out on this one. Scientific, regulatory and insurance professionals are divided, even among themselves.
Anecdotally, during the past few months, I’ve followed the stories of veteran tornado-watchers who’ve never seen anything like this season. To them the April 27 tornado in Tuscaloosa was amazing until Joplin came along. And then, Massachusetts became national news.
Numerically, this year’s tornado frequency is well above the long-term average, which has risen over the past 50 years. Most meteorologists see nothing at work beyond the volatility of nature. Statisticians see at least some of the rise as the result of better record-keeping.
Historically oriented climate scientists suspect there’s a change in the air, especially since the previous year experienced almost record-breaking heat, the energy from which tornadoes are born. Insurance companies are rethinking their long-term rates for customers. It’s still too early to tell whether this is due to climate change, because such assessments can only be done in hindsight.
For those who are getting concerned, a well-informed and politically neutral report, “Weather and Climate Extremes in a Changing Climate,” was published by the U.S. Climate Change Science Program in 2008. It’s available online for free (http://courant.com/noaa). One of the report’s most straightforward conclusions is that, on balance, a warmer world will be one with more extreme events.
Southern New England may lie beyond tornado alley, but as we have just witnessed, it has all the ingredients for making violent funnel clouds. We’ve got the conditions of warm, muggy air. And to the west north-northwest, we’ve got masses of cold, dry air that sweep our direction. Though tornadoes result from several distinct meteorological scenarios, many form when cold air lifts warm along a boundary called a cold front. The resulting updrafts and downdrafts create a line of thunderstorms that, when conditions are right, create tornadoes as a side effect.
It’s fortuitous that we’re well removed from oceanic moisture near the Gulf of Mexico; downwind from the Appalachians in the prevailing flow; and that our hills and forests sap incipient tornadoes of their power. But when adverse conditions coincide, these factors are overwhelmed with terrible consequences.
Perhaps you learned as I did when a child, that tornadoes are miniature hurricanes. It’s a story less true than that of the Three Little Pigs. Hurricanes are the giants of myth, entities unto themselves, enormous air masses that strengthen and then track for days. Tornadoes are the trolls of myth, each a small, transient, unpredictable and dangerous expression of something larger and more powerful – our climate.