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May 20, 2001: Tornadic Supercell in Eastern OK

(Dave Lewison, Chris Kridler & George Kourounis)

Click any image to enlarge to full size...

520.jpg (45235 bytes) Started the day in Denison, TX, after the previous day's complete washout in the TX panhandle. (The huge outflow boundary that scoured out all moisture, and with it, any hope of storms).

We hung out in Sherman, TX, at a local truck stop getting data and enjoying the assortment of pies they had. Very good! There was a large instability bulls-eye in our neighborhood, but the main upper dynamics looked to be setting up further north. A stalling outflow boundary near I-40 sealed our decision to head north towards Atoka.

A quick data stop in Atoka revealed two storms beginning to fire to our north. Both were kind of spindly looking, but we decided to target the western most cell, thinking it would make the easiest intercept.

520wallcloudsm.jpg (7584 bytes) 520overpasssm.jpg (13933 bytes) Near Wetumka, OK, we got a view of the storm's base to the west. It had a very suspicious looking protrusion, but we later saw that this feature was not rotating much.

Hearing the tornado reports just to our east near Dustin, we decided to head that way to investigate. We stopped on an overpass and saw the utter confusion happening on the Indian Nation Turnpike, near the town of Hanna. These people were not chasers, just worried travelers.

520TVradarsm.jpg (17755 bytes) 520dirtroadsm.jpg (12844 bytes)  

Now within range of the Tulsa TV stations, we got a clearer view of what we were up against. Our location on Rte. 9 is shown in the picture.

Unfortunately, we had to deal with a little eastern Oklahoma topography first.

520stiglertornadosm.jpg (9608 bytes) 520stiglersm.jpg (12052 bytes) After having followed in the hook of the storm along Rte. 9 for quite some time, we began to pull ahead slowly near the town of Stigler. Just before town, I noticed an interesting pointy lowering just off the the north of the road (about 1 mile NW of Stigler). This is a contrast-enhanced image. The tornado is the dark area to the left of the tree.

Once in Stigler, our winds switched from NW to S and increased dramatically. There was no doubt in my mind that an intense circulation was just north of town. View here is to the east on Rte. 9.

520meso1sm.jpg (8037 bytes) 520nightradarsm.jpg (17507 bytes) We continued following the storm to the east, periodically getting in front of it to take pictures. You can barely make out the meso here with an inflow tail off to the background. View here is to the North. The storm appeared to be turning into a HP hailer with almost no visibility, so we decided to give up and head back SW towards McAlester.

However, we weren't done yet. Heading back west on Rte. 270, we encountered another supercell east of Red Oak. It, too, had a nice looking hook echo. That dark blob is my fat finger pointing at where we were. We stopped in Wister to observe. Unfortunately, it was 9:30 PM and totally dark, and a mountain ridge blocked our view of the base.

 520nightwindsm.jpg (9189 bytes) We were treated to very gusty winds, hail, and power flashes though.
520lightning2sm.jpg (11788 bytes) 520lightning1sm.jpg (9882 bytes) Continuing back west towards McAlester, we encountered another TWO severe storms with frequent CG lightning.
Summary:
Overall, an interesting day. I just wish we had decided to intercept the eastern storm at the beginning, which was the one that produced the pretty multi-vortex tornado near Dustin. If we had decided in Atoka to take 69 northeast instead of 75, then we could have done it, but there was no way to know it would be the better storm.
Heck, even the DOW's took our route! Well, that's chasing for ya!

Email me at: dave@facethewind.com

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