May 30, 2022

My email to the group:

"We like the north play scenario. Deepening low, height and temp falls aloft, strong LLJ, diverging northerly midlevel jet, should be numerous supercells. We're going to make a play on Round 1, which is early development on the surface low in the Sioux Falls vicinity by early afternoon. We're going to use the 80 mph speed limit on I-29 to track cells toward Watertown. Then we expect to scoot across a Red River crossing into Minnesota for a Round 2 coming off the dryline, where moisture convergence yields forecast strong instability coupled with favorable shear. Continued height and temp falls should force a really intense line. We may just play down the line by running east and letting cells pass over us as they mouth south to north, probably winding up in the Alexandria to St. Cloud area. Models show a mess, but pattern recognition makes me think storm mode will be a broken line of supercells."

Anton's thoughts:

"Today… my goodness, this is one of the more complicated setups I can recall. First principles first: (1) this system has the strongest late-May 500 mb flow I can recall, with an exceptionally well defined jet streak; (2) the warm sector is fully juiced with high CAPE; and (3) the areas advertised by the morning CAMS for widespread rotating convection in eastern SD and western MN are not well juxtaposed with both 1 and 2. Under the circumstances, what is an avid suntan-loving oversized ground squirrel to do?

The overnight convection has laid out a sharply defined outflow boundary that is lifting northward through northeast Nebraska as a warm front. The Roger Edwards 13z SPC outlook calls for it to mix out as an intense low-level jet hauls the high energy air northward. I have yet to see evidence for this in observations, however. Further west in Nebraska, cells are firing in over cold air from Ainsworth SSW to Gothenburg in response to the incoming upper level forcing.

It therefore seems plausible that the forcing will trigger new convection before 18z in the increasingly uncapped warm sector over Nebraska as it expands northward across the Missouri River. Echoes now developing near Burwell may be the precursor to such activity. Woodchuck plans to situate on the northwest apex of the warm sector in the chance that one of these cells roots in the boundary layer and remains discrete as more linear convection erupts further north and northeast. If this scenario fails to materialize, we will head north through Yankton and try to work the southern end of the developing line of twisting South Dakota updrafts. "

Getting the motorized camera enclosure ready for the chase. When fully completed, "The Toad" should allow for an unobstructed 360 degree shot, which would be needed on a day like today with lots of fast moving storms and little time for stopping.

Strong diverging northerlies running ahead of the higher cape air on the SD/MN border was the pattern. Models showed messy convective trend, but with deepening low was optimisitic for tornadic supercells. We left early to get on the early afternoon play near Sioux Falls. Skies were cool and misty.

We double backed for a cell southwest of Madison, SD that picked up a tornado warning. It quickly became rain wrapped and was swallowed by the developing line before we could get a visual on the area of rotation, so we scrambled east to stay ahead of it. We crossed into Minnesota, gassing up in Pipestone and then watching the approaching line from the edge of town. Doug Raflik stopped by to say hi.

East of Madison we noted multiple areas of interest with low level rotation on the lead edge of the gust front.

A couple of them looked like brief funnel clouds.

Brindley spotted a momentary corkscrewing tendril of condesation flick up from the ground off her right shoulder while I was driving. It was too fast for either of us to get a camera on it, but other chasers reported it as a tornado. We decided not to count it, being unable to document it ourselves and because of its fleeting, weak nature.

We stayed ahead of the line as a couple more tornado warnings were issued for circulations that were embedded or on the lead edge like a QLCS, but the line quickly congealed and we never really had a discrete play on anything. We watched the gust front for awhile before running east to stay ahead of it again, but storms were starting to dissipate so we began to stair step our way down to Albert Lea for the evening. Surface winds in the warm sector were gusting above 50, rocking the car and kicking up large amounts of dust.

We called the chase and checked into the same Albert Lea hotel we were at a few days ago. Chilling on the patio with a pizza, we were completely oblivious to the sky behind us until Brindley went out to the car to grab a ginger beer. And there stretched across the southern sky was a spectacular mammatus display.

Brindley raced to get her camera and a wide lens while I snagged a few shots with my phone.

Along with a few other people in the parking lot, we marveled at what was the most spectacular mammatus display we had seen in years. Looking around, I then realized Brandon Ivey was standing next to us and the group was his tour that he was leading. They had just stopped for dinner before continuing on their way.

We spent the evening at the same fire pit where we were on the way out to the Plains. Unfortunately Brandon's tour van was having mechanical issues and wouldn’t start, so they wound up joining us at the fire pit, and spending the night. We hung out until the squall line eventually caught up with us. I believe they were rolling the next day without issue, and there wasn’t much to miss anyway.