Monday, February 18, 2008

Tornadoes Connected to Global Warming?


Toto, I've got a feeling we’re not in Kansas anymore—Dorothy Gale

Does the Flap of a Butterfly's Wings in Brazil set off a Tornado in Texas?—Edward Lorenz

Do you believe in fate? I must confess that there is more to my global warming nightmare than I had let on earlier. About a week before having that nightmare, I went to Louisville, Kentucky, to visit a friend recovering from an illness and during my short stay I experienced a winter tornado! I didn’t even know I was experiencing the ripping force of a twister until the day after, when I heard it in the news.
It started on the evening of January 29 at around 8pm. It was dark and I’d just entered the grocery store for supplies when a severe storm swept in like an angry god, hailing down a deluge of wind and rain and drawing the attention of the store keepers. It cast down the store’s huge neon sign, smashing the car below (three cars from my rental) and blew down trees and power lines everywhere. My drive back to my friend’s place was an obstacle course as I swerved around sparking power lines on the road, fallen branches and debris and totally uprooted trees. One of the tornadoes touched down twice just blocks from my friend’s house. It burst windows, destroyed cars, signs and buildings, ripped off rooftops and uprooted concrete driveways and massive trees and left my friend’s house (and neighbouring houses) in deep darkness, prey to the vagaries of a howling wind. I now know why the lovely heritage-style houses in this part of Kentucky are made of brick. Remember the lesson of the three little pigs?...

I discovered later that the tornado had touched down four times in Louisville and was 100 yards wide and an EF1 strength tornado on the Enhanced Fujita Scale (used to rank twister destructiveness; see below). NOAA’s National Weather Service Forecast Office reported that “a powerful cold front sparked a lengthy squall line that crossed all of southern Indiana and central Kentucky on the evening of January 29, 2008. A large number of locations had 60 to as much as 100 mph winds, causing extensive property damage.”

The January 29 storm was followed by another spate of tornadoes on February 5/6, which wrought even more damage, with many a person spending a harrowing night punctuated by breaking glass, sirens, rain and hail as tornadoes “tossed trailer homes into the air, collapsed the roof of a Sears store in Memphis, whittled away half a Caterpillar plant near Oxford, Miss., and shredded dorms at Union University in Jackson, Tenn.” (New York Times). One thousand houses were destroyed in Tennessee. Much of the havoc was caused by rare “long-track” tornadoes, which stay on the ground for distances of 30 to 50 miles. One tornado in Arkansas burned a path of destruction through five counties before lifting, according to Renee Preslar, public education coordinator for Arkansas Emergency Management. I read about one tornado in Broken Bow, Oklahoma, that carried a motel sign 30 miles and dropped it in Arkansas.

Accuweather.com labeled the January/February cluster of storms “historic”. These unseasonable tornadoes (as winter tornadoes are called by meteorologists) that swept the mid-southern states claimed 55 lives and injured hundreds of others (New York Times). Called the deadliest set of tornadoes in memory by Environment News Service, ninety-one tornadoes touched down in Arkansas, Alabama, Mississippi, Tennessee and Kentucky (where I was).

In addition to the tornadoes, 109 cases of hail and 189 cases of high winds were reported. According to John Kocet, Senior Meteorologist at Accuweather.com, the hail was more than two inches in diameter. He added, “To have such a large tornado outbreak so far north during midwinter is quite unusual to say the least.” Tornadoes are not typical in the winter. Kocet said that the storms were formed by clashing air masses and wind shear, a change of wind direction and speed with altitude. Unseasonably warm and moist conditions across the Mississippi and Tennessee River Valleys were a major factor in the formation of this spate of tornadoes, according to Greg Carbin, warning-coordination meteorologist with the National Severe Storms Laboratory (NSSL). Temperatures as much as 25 degrees higher than normal spawned this deadly set of storms. “The big problem is that [winter] tornadoes themselves tend to be moving faster,” said Harold Brooks, a research meteorologist with NSSL. He said this is because the winds in the upper atmosphere that produce tornado-spawning thunderstorms are faster in winter.

Many of the tornadoes were rated EF3 on the Fujita scale with winds raging 158 to 200 mph (254 to 322 kph), causing severe damage. Only 5 percent of tornadoes reach at least F3 intensity and cause at least 70% of tornado fatalities, said Brooks. (National Geographic News).

Senator John Kerry suggested that the frequency of unseasonal severe storms and tornadoes is the result of global warming. In an interview on February 6th, he called attention to scientific predictions that link stronger storms, including tornadoes, to rising atmospheric temperatures. Kelly’s suggestion was met with cool skepticism from scientists to outbursts of rage from conservative groups.

While no weather event can be scientifically attributed to global warming, climatologists have predicted that wintertime temperatures, more than summer temperatures, will increase due to global warming (New York Times). The Daily Green asserts that data already shows that winter and nighttime temperatures are rising faster, on average, than daytime and summer temperatures and that strong thunderstorms and tornadoes will be more frequent as a result. More than 1,000 high-temperature records have been set already in 2008, according to Gannett News Service. NASA scientists have found a greater chance of updrafts (the precursor to thunderstorms and tornadoes) due to warmer climates. NASA developed a new climate model that indicates that the most violent severe storms and tornadoes may become more common as Earth’s climate warms, adding that “the central/east U.S. experiences the most severe thunderstorms and tornadoes on Earth.” Meteorologist, Harold Brooks, doesn’t think that global warming is the cause of increased unseasonal tornadoes (National Geographic News), although he suggested that La Niňa (the cooling of tropical waters in the Pacific Ocean) may have contributed.

The Glossary of Meteorology defines a tornado as: a violently rotating column of air in contact with the ground, either pendant from a cunmuliform cloud or underneath a cunnuliform cloud, and often (but not always) visible as a funnel cloud” For a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base (Edwards, 2006). The word tornado comes from the Spanish word tronada, which means “thunderstorm”, and the Latin term tonare, which means “to thunder”. Tornadoes range from weak (most common) to violent, and their intensity is rated on the Enhanced Fujita Scale (by damage caused). For instance, the EF1 tornado that I experienced is associated with winds from 60 to 110 mph with some structural damage (e.g., roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken) whereas an EF3 tornado (136-165 mph wind) causes severe damage (e.g., entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance). Tornadoes vary in shape and size and type. For instance, meteorologists have catalogued multiple vortex tornadoes (with two or more columns); satellite tornadoes (a weak tornado near a large one); waterspouts (tornadoes over water); and landspout. Their shape can vary from a narrow funnel, a few hundred meters across to a small swirl of dust on the ground or wedges. Tornadoes may resemble narrow tubes or ropes (e.g., rope tornado) and may curl or twist into complex shapes (e.g., roping out). Tornadoes will often take on the color of the debris they kick up. When back-lit the tornado would appear intensely dark but if viewed from the other side may be brilliant white. Sunset tornadoes may take on a yellow, orange or pink hue. Nighttime tornadoes often appear like a specter, illuminated by lightening. Apart from the roaring storm sound, tornadoes produce infrasonic and seismic signatures and emit on the electromagnetic spectrum. Field research programs like TOTO (the TOtable Tornado Observatory) and Dopper On Wheels (DOW) are solving many questions still plaguing meteorologists about tornadoes.

It was nighttime when the tornado storm that I experienced swept across the quiet town of Louisville. Although I experienced the freight train roar and associated heavy rain and gusting wind, this is what I would have seen if it had been daytime: I would have been staring at a dark, possibly greenish sky and an intense wall cloud, rotating and moving ominously toward me...then the condensation funnel descend as wind gusts slammed into me and kicked up dust and debris... Finally, as the funnel touched ground, I would have seen the destruction of trees, buildings, signs and cars… It’s probably just as well that it was night time…

But here's the rub (as Hamlet would, and did say) and as I return to my question at the top of this post about fate ... Like my friend and colleague, Teresa, I believe that everything happens for a reason (whether we can fathom it or not). Here's what I think: I was meant to visit my sick friend in Kentucky not just to help her out but to experience that tornado...



Recommended Reading:

Edwards, Roger. 2006. The Online Tornado FAQ. Storm Prediction Centre.
Glossary of Meteorology, 2nd Edition. 2000. American Meteorological Society.





Nina Munteanu is an ecologist and internationally published author of novels, short stories and essays. She coaches writers and teaches writing at George Brown College and the University of Toronto. For more about Nina’s coaching & workshops visit www.ninamunteanu.me. Visit www.ninamunteanu.ca for more about her writing.

10 comments:

  1. Those particular storms were caused by an interesting pattern in the Jet Stream, which I wrote about at the time. It was broken into little pieces, and as they circumnavigated the globe the southerly one caused a lot of havoc - including the nasty ice storm in China.

    Since that time, they have evened out some - but not completely. Weather patterns like this go 'round about every 12 days, and we're seeing the same blip right about now. It's caused some cold weather here, but that's it. It's smoothed out substantially.

    Will these become more pronounced with global warming? The standard response is that the bubble of warm air over the equator will simply push the Jet Stream further north. I happen to think that it is about as likely to create more turbulence at the boundary, especially if the troposphere is considerably taller than it used to be. That means more of these kinds of Jet Stream deviations.

    It's not an effect that is generally predicted, however. We'll just see.

    ReplyDelete
  2. The weather certainly does seem more varied and traumatic in these times, which would suggest that the climate is evolving.

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. Interesting observations, Erik...And, yes, good choice of words, Jean-Luc... climate evolving... we'll just see...

    ReplyDelete
  5. Nina, your question, “Do you believe in fate?” though very simple (it containing no more than five words) has profound implications, and as such not at all easy for me to answer.

    You say: “I believe that everything happens for a reason (whether we can fathom it or not)”

    And I would add, Nina, I believe that I happen for a reason whether I can fathom it or not or whether anyone else can fathom it or not… :) I wonder have I just said something profound or not. Or is Profundity merely playing with me?

    Last night in a dream, I was with visiting my childhood home here on the island. And with viewing the southeastern sky, I beheld an airplane flying low in from the southeast. As I was watching it, it turned in my direction, and while doing so ‘coiled’ itself into the shape of an almost ‘flatten football’ which was rotating and hovering soundlessly. It looked very beautiful and it was about half the size of an acre.

    With watching it, I knew ‘they’ were back and I felt good about that. Then I found myself drifting away into another scene in which I could ‘see’ the visitors from [who knows were] transforming themselves from being invisible into everyday people just like you and me. And I was thinking to myself (in the dream) that this is something I have always known… And then I awoke.

    Now how can I apply fate to this dream? Did it happen for a reason?

    Lyrically, are tornadoes giant ‘ice-cream’ cones for giants? Now where did that thought come from; coming as it did quite unannounced? How would I know they to be so or not to be so? Who could I ask that would know? Might Will of Avon know? Ah, methinks no. :)

    Fathom-ly,

    Richard

    ReplyDelete
  6. Well, Richard, I'd say you did answer my question quite nicely! As for your dream... Very cool! "I knew ‘they’ were back and I felt good about that. Then I found myself drifting away into another scene in which I could ‘see’ the visitors from [who knows were] transforming themselves from being invisible into everyday people just like you and me. And I was thinking to myself (in the dream) that this is something I have always known… And then I awoke."
    Your question (referring to your dream), "did it happen for a reason" provides a wonderful opportunity to contemplate what dreams really are, what they mean and where do they all go...

    ReplyDelete
  7. OUTSTANDING POST...:-) You simply light up my day.
    http://climateofourfuture.org/you-light-up-my-day-award/

    ReplyDelete
  8. Hey, lady! YOU'RE the one lighting up people's days! And minds and hearts!... Thanks for the award, Deborah! I'm honored.

    ReplyDelete
  9. Amazing post!

    Tornados are the one thing that frighten me...I can barely look at the photos. Don't know why, never seen one. I have seen funnel clouds...they were scary enough.

    ReplyDelete
  10. Yeah... Tornadoes ARE scary. I think what makes them particularly scary--aside from their incredible force and destruction--is how unpredictable their movements are. My Kentucky friend was apparently "chased" in her car by one across an open field!

    ReplyDelete