Although there was a thunderstorm watch for the area, this storm surprised me with it's fierceness. I watched the small blob grow on radar screen and decided to go take a look before I had a get together later in the evening. I have a great vantage point to watch storms about two miles from my house. It's a local farm field that the hedge rows were removed and I can see way out west.
When I arrived, I noticed a definite lowering of the clouds.
The wall cloud was forming and feeding off of the huge amount of moisture to the north of it and building although rotating very slowly.
There was some radio chatter about a rear flank downdraft opening up but I never saw it. Quickly the wall cloud slimmed down and continued feeding on warm moisture.
I was in a good position with inflow directly overhead. It kept the rain from cloaking the area. The cloud slowly rotated and radar finally indicated a cause for a tornado warning. If there was a rear flank downdraft, I think it choked out the tornadogenesis as the wall cloud became smaller. As it became smaller it began to rotate.
It was rumored that the storm was moving SE instead of straight E. Unfortunately, that's where my house is.
Part II coming soon.