Thursday, April 30, 2009

A few more details

Pretty frustrating day as I mentioned on the nowcast part of the boards. Left Odessa after lunch to see storms to the north and a red box issued for them. We cruised north realizing the dry line had mixed further east than I though. I should have known that it was going to be loosely defined since it was not dynamic with a well-defined pressure trough. As we finally got back into the better moisture near Big Spring it became apparent that nothing was going to happen with that wave. What is it with all the high frequency short waves this year?

We saw the storm that was about 50 miles south of Odessa go tornado-warned but decided we were going to stay within our forecast area and not chase it.
We did think that the newly formed outflow boundary would be a great mechanism for new storm growth and tornadic potential with enhanced vorticity. But of course, no storm formed in that region at all. So after making it to Gail, TX, it became clear to us that the only real good storms we north of that boundary along some of the older (and colder) ones further to the north. Wind fields were weaker but you have to have storms before you can have supercells.

So we flew north (gosh I had forgotten how beautiful that part of TX is!) The storm that came off from Plainview (which btw was in an area of cu's that had been present north of the dry line bulge) was moving more easterly. Further to the west that was a real good supercell with tor's out and several other cells forming on some old boundary. They had a more northward moving motion to them and I felt that the storm out west could move just south of those others and move right along a better moisture or outflow feed.

As we were near Floydada, we could see excellent tower growth to the NW so we pressed northward. As we approached there was a high based shelf cloud that looked almost base-like. Given the conditions, I felt that could not be the true base. Matt Powers texted me that on radar it looked like a big cold machine and I agreed. Nonetheless, I felt we needed to get a better look. Inside that base (and wide RFD) I saw a lowering, not unlike other HP storms with the low scuddy wall cloud. Given its proximity to earlier convection I wanted to make sure that it was really cold inside there. Heading north our driver radioed that it was a tornado he was observing possibly. I warned him to be careful of those words over radio and we were still too far to be sure.

We moved north and it was a large barrel-like cone as Scott Blair indicated. We were driving right to it. We got out and snapped some pics.

A second tornado formed to its east at the same time. Enhanced shear along the gust front I reckon. We got onto some really hairy mud ruds so we headed back south and west. A student believes that there was a third tornado and I tend to believe him. (so that might make Scott B's third if he did not see the secondary needle.)

After heading south I saw vigorous cloud growth and figured I would bust south near Dicken's to get to these storms in less tainted air. There were impressive towers. Just east of Dickens we saw a great looking and scary storm. Todd Lindley from LBB called me and said they were interested in that storm as an OFB from the north storms was surging south and about to interact. We watched for a while and there was very strong low-level rotation. Unfortunately just as I though it had a chance to tornado, temperatures dropped like a rock and I knew it did not have a chance.

We were not going to play in the core so we bolted west and south to get out of its beasty path. Lots of loops and CC bolts made it fun to watch for a while. All in all, a saved day.

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