Duncan, OK Supercell

March 17, 2003

Left Norman just after 4pm this afternoon to intercept a lone storm in southwestern OK. The Hobart storm had already done its thing and other cells continued (albeit maybe a little weaker) in that area. Low-level theta-e advection looked pretty good (on SPC mesoanalysis page) down in SW OK, and mesonet obs showed backed winds both near Hobart and in SW OK, so essentially made a flip of the coin, and went SW.

We basically went right by the first tornado-warned storm down there, as we thought it looked *very* messy and weakly organized by the time we got close to it, and we could see a good-looking storm to its west. Were (conveniently) driving through Duncan when Jeff P. radioed in his tornado report (needle tornado), catching glimpses of the base through downtown while he was talking... didn't see a tornado, but we weren't close enough to confirm for ourselves whether or not a needle tornado existed. Either way, it was very brief. By the time we emerged from town about a minute or two later and had an unobstructed view of the action area, it was clear there was nothing there.

First view of the westernmost Duncan, OK storm

From that point on, we observed pretty nice supercell structure, but somehow, nothing that made the bells and whistles go off in my head about a tornado. Occasionally, scud would rise from fairly close to the ground, with no obvious rotation from our vantage point, and the spotters went nuts reporting a funnel cloud, even when it was somewhat detached from cloud base. There *was* storm rotation, and it was a supercell, but the wall cloud/scud elements did not have rotation any greater than what they'd have if they were in solid body rotation with the rest of the base. (See here for a timelapse movie of the storm.)

Scud rising into updraft base.

Mesocylone of the storm with collar cloud and wall cloud.

Same structure a few minutes later.

At one point, we were coming through Marlow, OK, and one of these items came much closer to the ground, but again, we could see no significant rotation with it, despite the fact that the larger base had some weak to moderate rotation. Some one (Daphne and Jim??) radioed in "no significant rotation", and I chimed in to support that claim. Understandably, they weren't too happy to have someone from out of town disagree with their veteran spotter reports. I'm certainly not offended by that, since the item did *look* rather menacing, and I can be just as much an idiot as anyone else. I just didn't feel I was an idiot at that moment. It did not touch down.

Second scud item reported as a funnel. It looks really suspicious, but rotation is negligible.

Same item about a minute later.

Overall, very happy with the first chase... saw two supercells. Not unhappy about missing the Hobart tornado, as I got a fair bit of work done this morning and early afternoon. One thing is very clear to me... those who are most optimistic and take their chances against what seems to be some negatives with regard to the severe potential will do the best in this game. There is very rarely a day when things look very obvious.

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