All images and text © copyright Gene Moore unless otherwise indicated.
On 24 May 1989, a dryline and intersecting jet stream produced a series of severe storms across Minnesota, Iowa and northern Missouri. This is the best tornado we have photographed in Missouri. It was 3/10 of a mile wide at the largest and had a damage path of 11 miles in length. The tornado was down for a little over 20 minutes. Officially, its listed as a small short track event, but the damage path as we measured it was much larger than the condensation funnel on the ground. Images of the tornado at it's greatest width are not available as it was buried in rain at that time.
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Our chase began as we traveled south out of Iowa on a series of farm roads and joined the interstate near the Missouri border. In the first image the main storm complex is on the left with the anvil overhead. At center and right is the flanking line of cumulus that is feeding into the storm. This is the updraft region of the storm and we intercepted the region where this updraft meets the rain core of the storm. The tornado was forming overhead as we neared the town of Blythedale.
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After the tornado passed we measured the path width where it crossed in front of us in the rain. We saw many busted and destroyed trees, fence posts and power poles use for our measurement. The path width measured just under 3/10th's of a mile wide on the car odometer. This is much wider than the width of the condensation funnel, and probably only lasted for 2-3 miles of the total length. Officially the tornado was much smaller than this width. |
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The tornado is one mile to our north moving east in this image. The bottom of the funnel was beginning to narrow considerably from the first time we saw it in the rain. At this distance we can hear a swishing sound and cracking as the tornado breaks trees. A grey swirl of debris covers the bottom third of the funnel further reducing the contrast. The colors change as dry air lets more sunlight into the storm. |
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At this time we had gotten enough light from the west to improve our photography. Mike Watts took advantage of the scene to get some vertical shots of the tornado. The funnel remains up against the rain wall of the thunderstorm, but quite visible to us. I saw no lightning during the time we did this photography. There was considerable lightning, thunder and hail near the interstate when the tornado was forming. |
The funnel is shown here in the rope stage. It has been down
for 15 minutes and covered almost ten miles. It continues in the rope stage for
another five minutes for a total of 20 minutes of down time, which is longer
than most of the tornadoes we observe in a season. Note, a small white contact
point may be seen below the funnel. |
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At this point I have to ask.....is the fun over? The rope stage persists much longer than we anticipate. The funnel at one time reforms and gets larger then narrows again going through a second rope stage. Thinking the show was over, we let the funnel take off to our east, only to have to catch up again for more "rope shots". |