Summary of the day: June 29, 2017

Thursday was supposed to be the day.

We outlined 4 areas, all with pluses and minuses.  The #1 target was northeastern Nebraska. #2 was southeast CO. #3 was northeast KS. #4 (not chaseable) was around Buffalo, NY.

We got going north to our initial target of Norfolk, as the surface low was very close to there. We had a quick lunch there and came out to see big towers going up to our northeast, right on the warm front emanating eastward from the low.

We followed it along and it grew rather quickly as we approached it. Once its tops reached about 50,000 feet it got severe warned. It even had a TBSS on it.

The storm quickly split and started rotating. As we approached it, we got up on a hill and saw a couple of attempts but it couldn't focus its rotation.  We got back on the highway and the storm continued to strengthen, as did its RFD. We had to stop a couple of times a) to watch and b) to avoid the rotation on the storm.

Navigation became an issue, though, as the storm was heading straight for Sioux City. The problem with that is the Missouri River, which has one crossing right there and another about 30 miles to its south. We decided to tuck in closely behind the storm, cross the river and then get ahead of it once again. We passed through some heavy rain and some hail along the way--through Sioux City there were some hailstones that might have been quarter-sized, maybe a touch larger.

As we once again got in view of the storm, it showed us some decent structure but then another storm started to go up to its south. Destructive interference was occurring so (after a flat tire scare) we dropped south to see if the south one could organize.  And it did.

The roads, hills and trees made it difficult to get more than a glimpse of the storm, but we could see (both visually and on RADAR) that this storm was quickly organizing.  We finally found a good option south of the storm where we could see it, and a glorious scary supercell was right in front of us.  It had a fairly round bowl mesocyclone, and a good inflow tail was hugging the ground.  It made a few attempts to produce a tornado in the green hue, but (again) couldn't quite focus the rotation.

After that, the storm lined out and then another south one tried.  That farther south one didn't do as well and linear forcing was becoming more prominent, so we called the chase for the day and for the trip.

We had dinner at Texas Roadhouse in Sioux City and stayed there for the night.