May 27, 2017

Team Duck’s (remote) Forecast:

“This is looking like a messy targeting day at this stage, though I will be watching guidance closely today when I can. The models don’t want to blow up anything in Eastern OK until a pair of massive squall lines form. I think with the giant CAPE, impressive mid-level dry slot, modest deep shear (but enough with the shortwave) and rich deep dew points we are looking at a very very primed MCS environment (possibly the D word) - perhaps started by HP supercells or with rotating storms embedded. NAM tends to favor this solution - actually maintaining the previous evenings MCS from CO and subsequently spawning something mean and MCS through SE KS/MO/AR/TN/MS. Pretty much keeps things quiet in OK as well, until outflow from the northern MCS smacks the cold front and blows up to all hell with a SE propagating system. In either case I forsee a rich vein of wind reports. I wouldn't be surprised to see a wind driven moderate from SPC. Tornado threat will mostly likely be a lot lower and probably early or bust or perhaps if a storm can hit a boundary before getting caught up. Unfortunately, it looks like the warm front is going to stay too far south to make it useful for a local chase in the IL/IN corridor (too many trees down there), though I'll keep watching and make a call Saturday morning based on the surface analysis. Given extreme CAPE (AOA 5000 J/kg, possibly even higher depending on the model), and 45 knot shear, supercells with pretty intense buoyancy driven stretching early on, or possibly longer if they can find a boundary. Given there isn’t much of an option for a show elsewise – I would consider relocating yourselves toward south central KS to be in play for tomorrows show if you are wanting to get a shot here. There may be a play in northern TX given the better shear and more discrete supercell potential.”

Team Turtle’s Forecast:

“Real briefly here. Turtle is about ready to roll. Would suggest making a quick and early run east of El Dorado, KS to get storms at initiation. Explosive development of updrafts with maximum stretching while storms are discrete may give us a visible tornado shot ala Roanoke, IL July 2004. Models are saying 18z so we need to boogie east now due to open cap and explosive instability. The initial MCS may race off to the east. We could play further down the dryline/cold front into ne OK afterwards as we get later development.

Secondary target would be off the Ratan toward Pueblo. Nice discrete supercell being plotted over there. Thermodynamics are quite marginal for tornadoes, however. 500-750 SBCAPE 50-75 0-3km MLCAPE. It could squeak one out and lapse rates, especially in the low levels will be steep. Prettier storm than out east. But my inclination is if we are out to measure the fastest winds on Earth we should be making a play for the strong tornado target.”

May 27 was the last chase of Brindley and my several days run with Anton and Tracie across the Plains. Instability was forecast to be extreme with explosive updrafts making for the possibility of a violent tornado along the warm front. The setup was hyped, probably too much. We were hopeful this would be our biggest day of the run, however. We left Garden City, Kansas making for the southeast Kansas/Oklahoma border under a really cool looking scalloped sky: the turbulent wave pattern left in the wake of an overnight storm complex.

We met up with Anton and Tracie on the lake at a state park north of Bartlesville, Oklahoma. The air was hot, humid, and hazy. It was a great day to be on the lake, but bumming around in a hot parking lot waiting for storms, not so much.

Team Woodchuck

Squire

Towers were going up by midafternoon, rocketing up in the extreme instability with pileus caps. We sat and watched them, waiting for a dominant cell.

The lead and dominant storm went up way to our east past Vinita, leaving us behind as we made a mad and futile effort catch up to it.

The lead cells were converging into a complex while new updrafts were unzipping behind us to the west, right where we had begun the day. We double backed to Bartlesville, meandering down country highways and through small town. We spent two hours driving around before we finally had a visual on a base. It looked like a classic supercell as we approached.

Terrain isn’t ideal in northeastern Oklahoma between the hills and trees, but we found a few spots. Our storm looked like it was attempting to organize with a wall cloud. It, and the others unzipping east to west, were solidly north of the warm front/outflow boundary. Inflow winds north of the boundary were slack and the base appeared stagnant. We feared our storm would never root to the boundary, staying quiet to the north of it.

Oklahoma in May on a 10 hatched day means the roads are thick with storm chasers.

We went south to catch our next east highway to keep up with the storm. We passed directly underneath the rain free base, which was totally uneventful. The storm had peaked and began to wither in the golden evening light.

We spent the next couple of hours zigzagging through the hills and trees of northeastern Oklahoma, getting into progressively worse terrain chasing progressively messier storms. We finally called the chase at dusk under whale’s mouth structure and cut north for the turnpike and for home.