June 30, 2020

From my email discussion with the team the previous day:

"Tomorrow is a difficult, complicated, and messy deal. It looks like multiple rounds of storms could rake North Dakota overnight and in the morning. It could be quite loud in the hotel rooms tonight with the thunder and wind. Hopefully hail and tornadoes are at bay in the overnight hours.

Current preliminary target is Bismarck, North Dakota at about 20-21z or 3-4pm Central. A training line of north moving storms is forecast to be ongoing from morning into afternoon as strong flow aloft from the south continuously drags up both storms and the warm moist air they feed off of. Disclaimer: I'm basing my target pick off the HRRR model. It handled today pretty decently in terms of initiation location, timing and mode. The NAM NEST has been utterly wacky in its convective trends, but it shows some agreement with HRRR again on big picture idea.

So back to the big picture idea, we catch new development off the southern end of the ongoing MCS, a Tail End Charlie storm where parameters are maximized, as Tail End Charlie is a moving target that will keep firing further and further south as the day goes on. But from the HRRR solution, looks like a nice compact surface low and eastward extending CAPE plume with values approaching 6000 J/Kg feeding into the complex at this intersection point. Severe parameters peak at this 20-21z timeframe with the highest CAPE and low level flow which is starting to wane. I was a little worried about storms being caught behind what looks like a very sharp, convectively reinforced boundary. Think like today's blast of cold west wind we got as storms approached, but even more intense, and extending from the top of North Dakota all the way into Nebraska. But it looks like in that 20z to 21z time range, storms are still right on the boundary and potentially tapping surface based inflow. If storms are instead caught behind the outflow reinforced cold front, the tornado threat will be pretty much mitigated.

I'm also a little concerned about storm mode and how best to play this. Storms will be moving north again. Still a southwest shear vector on the HRRR, so they might present in a familiar configuration with the hook/meso on the southern flank or eastern flank of the storm. Hopefully we'll have a view from immediately east in the warm air, and we won't have to do something weird or hazardous like chase immediately north. But with stronger flow aloft displaced well to the west, I anticipate some problems with deep layer shear and storm mode as a result. We'll probably have a "squidgefest" here, where watery, sloppy clusters go up rather than crisp, discrete supercells. Tornado chances are fairly low as result, but the possibility is there, and it's close."

Brindley and I were paired up with Zack and Drea, a film crew making a documentary, while the rest of the team was scattered after the previous day's flat tire mishap in Montana. We spent the morning in Dickinson getting setup for action and interview shots. A DSLR camera was suction mounted to the hood of the car and bagged to keep the rain out. We'd be taking this into supercells and near tornadoes potentially, and I wondered if it would hold up.

Rolling to our Bismarck chase target and getting looks:

I picked a spot just outside of town for some interview shots with an appropriate storm chasing backdrop: flat, empty plains. Roads were muddy and treacherous so we had to be careful not to get stuck before the chase even began. Meanwhile the rest of the team worked on recovering the Seimons' van from Montana. The plan was to reunite in the afternoon for a chase through central North Dakota.

Storms fired. We went north out of Bismarck on the east side of the MIssouri River and then east to play the initial activity. We dropped south ahead of a congealing line of storms and then ran east down I-94 toward discrete cells firing downstream. Hank and the Seimons had gotten ahead of us I-94 and we planned to catch up with them near Jamestown on the discrete activity. Then the line immediately behind us started to kink with a distinct inflow notch and velocity couplet. A tornado warning might have also been issued, but one of those things prompted us to double back at the next exit and get back on the line. We drove north directly into the notch, stopped and found that we were looking at a developing QLCS tornado square in the eye. In the path of the mesovortex circulation, it was a tense couple of moments as we redirected the film crew north so we could safely film the circulation crossing the road.

We jogged north a mile and turned around to face south. A cone funnel cloud was forming, low contrast against the turbulent updraft base.

Extreme contrast edit:

The funnel looked like it condensed almost half way to the ground. Trees obstructed our view from confirming a ground circulation at the time.

Post event analysis using high contrast video showed what looks like a dust tube extending from the funnel at a forward angle to the surface. That would technically make this a tornado. It was super brief, weak looking, and not corroborated by other sources, so I'm not going to count it. But it doesn't surprise me either, as I'm under the belief that most well formed yet not fully condesned funnels beneath surface based storms are at least weak tornadoes, especially on these non-supercell cases.

The funnel retreated, but the rotation in the QLCS mesovortex was still extremely prominent visually and on radar. We reported the feature via Spotter Network, and I believe a tornado warning was issued shortly thereafter. It wasn't a big, photogenic tornado, but the funnel and circulation provided some excitement for the film crew to shoot.

We ran east, tracking with the inflow notch kink in the line with moderate to strong rotation in the QLCS mesovortex. Nothing on the level of our initial intercept was spotted again, however.

The rest of the day was spent chasing Whale's Mouths and gust fronts. The tornado show was over, but it was dramatic structure for us and the film crew to marvel at and shoot. We never caught up with Hank and the Seimons, but they had a similar chase noting circulations and gust fronts.

A scud funnel or another weak attempt in the QLCS inflow notch:

A little friend greeting Brindley at the hotel in Jamestown after the chase: