MARIETTA, OKLAHOMA TORNADO MAY 6, 2001
5:03 PM to 5:13 PM
Approximate Location of Tornado: N33 58.76 W97 10.25 (about 3 miles NW of Marietta)
Chasers: Amos Magliocco, Guy Story
Click on any image to enlarge.
MAY 6 2001 MARIETTA, OK TORNADO
Unable to ignore a setup so close to home, I traveled north on I-35 to Valley View. At the time, I had the idea I would stay within fifty miles of Denton to make it back in time to write my paper. The DOW trucks scanned from atop the Hockley Creek Road overpass, and I continued north of their position by about a mile, parking off the northbound access road. I pulled up a few maps and saw a moisture convergence and CAPE maximum more or less in our area and south, and that the dryline was bulging significantly in our direction. Surface winds that had been a concern in the morning blew briskly from the south and southeast, though they showed more backing in Southern Oklahoma.
As Steve Miller had analyzed in the morning, an outflow boundary lay parallel to Interstate 35, and I suspected this could also serve as a convergence mechanism, as per the 1630Z SWODY1. Soon I was joined by Guy Story, KC5GOI, and we watched towers to our west rise and fall victim to the shear, or the cap, or both. Finally a cell to the northwest gained some height, and while it looked weak on radar, the storm displayed a dramatic overshooting top. We left our location and drove north on 35. The storm presented a crisply backsheared anvil and solid knuckling beneath in addition to a powerful new updraft region southwest, apparently propagating along the outflow boundary.
We arrived east of the updraft around 4:45 PM where a prominent lowering hovered ominously over open fields. I exited the highway on a perfectly-positioned crossover and pulled to the side of the southbound lane. We enjoyed a perfectly backlit rain free base on this classic supercell, like a dream. The first funnels struggled to reach the ground, and finally at 5:03 PM black debris swirled beneath a thin, gangly tornado, which changed shapes and sizes several times during its ten minute lifespan. The tornado never grew particularly large or violent, but created some interesting patterns on the ground, including a possible multi-vortex display, though I'll watch the video several more times and show it to others before promoting that claim. Mainly it was a nice payoff to a long weekend of chasing and studying.
Afterwards, we drove east on 32 to stay ahead of a new updraft region. Another lowering formed just north of the road but retracted back into the cloud base. The rest of our chase was uneventful, continuing on to Durant, OK and filming dramatic towers against the red, setting sun. A great chase day.
Amos Magliocco's Storm Page