Storm Chasing in Tornado Alley
by John L. Daly
13 Aug 2002
plus - see this movie clip (.mov format, 2.7 MB download)
Chasing is a `sport’ which anyone can do – old or young, male or
female, athlete or couch potato, and people with disabilities.
All you need is a reliable car, a full tank, a camera, a good
map, and steady nerves! A little experience would help too - but
you have to start sometime.
was my idea of a fun activity for my visit to the United States during
May and June this year. I
spent the first few weeks touring many states, giving talks on climate
to community and university groups, and most of the remainder was spent
in western Oklahoma, USA, right in the middle of `Tornado Alley’ and
right at the peak time of year for them. After a lot of research about
these `supercell’ storms,
I wondered how the real thing would compare with how storms were
portrayed in the Hollywood movie, Twister.
first two chases turned out to be disappointing as the storms failed to
develop beyond ordinary thunderstorms.
Even the professional chasers from one of the research
institutions, with their
bright gleaming chase vehicles, gave up in disgust, as I saw them
returning to Oklahoma City on Interstate 40 in a neat single-file
convoy, just like the `baddies’ in Twister.
on Friday 24th May, my third such chase, I met a full-on
supercell for the very first time - actually two of them. My eyes
and ears for this endeavour was my colleague and friend Jerry Brennan,
who from his home in Connecticut was able to monitor real time radar
pictures from the Internet and convey the results to me by phone.
the morning of 24th May, Jerry informed me of an internet report that a
promising target area for that day would be Childress, Texas (see
radar map downloaded by Jerry, Fig.1), so I drove down there from my
temporary base (an old Route-66 motel in Clinton,
Oklahoma) only to find lots of ordinary cumulus clouds in the sky
stretched out in a fairly narrow band across the sky from north-northeast to
south-southwest. This was the
so-called `Dry Line’, the breeding ground for supercell thunderstorms
where dry air from the south-western desert collides with warm humid air
from the Gulf of Mexico. Other
storm chasers also arrived in the town, presumably acting on the same
information, almost turning the place into a storm chaser convention.
This was around 1 pm, and everyone was waiting around for the
expected afternoon thunderstorms to develop.
I remember wondering what the local people thought with so many
storm chasers in town.
We did not have long to wait. One of those harmless-looking cumulus clouds started to get bigger and darker than the rest, the cloud churning and `boiling’ so rapidly that it looked more like a speeded-up movie. Yet this was happening in real time. Within half an hour I could hear faint rumblings of thunder coming from it. Another half an hour and a cup of coffee later, I watched it hover over Childress, growing like some science fiction monster into a full-blown thunderstorm. Hail started falling and lightning was coming from the cloud. Then it started to move rapidly northeast, heading for Oklahoma.
this a typical day for a storm chaser?
Hardly. About 90% of storm chasing seems to be spent waiting,
more waiting, drinking lots of coffee, reading `War and Peace’,
getting bored and frustrated by the fine weather that others might revel
in, but which spells a day of impatient boredom for you. (On
two such days, I took an excursion to Roswell, New Mexico, hopefully to
have a close encounter with an `alien’). Only when the word
gets out that a supercell is forming somewhere, usually on a dry line,
does everyone rush for their cars and race across the high wide plains
to meet Nature’s most spectacular show.
As to the comparison with Twister, the reality was much different. I chased two more supercells on different days in northern Texas and found the skies are much darker than in the movie, black even, the lightning is all pervasive, not just pretty flashes, but high-energy bolts coming straight down from the low cloud to the ground in rapid succession. The rain and hail is a second major problem as the hailstones are so big that they can smash the windscreen of your car if you are not careful.
asked several local people in Oklahoma about tornadoes, and was
surprised to find that many of them had never actually seen one.
When the storm warnings go off, usually with warnings on the
radio and TV accompanied by loud wailing sirens, most people seek
shelter rather than hang around to get hit by golfball-sized hailstones,
electrocuted by the numerous lightning bolts, struck by debris from
violent winds, or swept up by a tornado which is often invisible behind
a dark wall of rain and hail until it is almost on top of you.
That’s why so many people have been killed or injured by them
over the years. During one of the storms I chased, near Pampa, Texas, a local
resident was struck by lightning.
I do it all over again? You
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