Brief tornado spin-up - 27th May 2018
The 27th May involved chasing an Enhanced severe weather threat issued by the Storm Prediction Center in far NW Kansas. The greatest tornado threat was in Wyoming, which was too far for us to chase - we therefore decided to stay in Kansas and wait for discrete supercells to quickly upscale into a quasi-linear system. The day involved a lot of backtracking on the same road network, as we had several false alarms from storms that initially looked interesting but soon decayed. We initially saw a nice gust front pass over us just to the south of Goodland, Kansas - lots of dust was kicked up (but there was no calamitous boot shenanigans as last time). We saw a nice shelf cloud in far SE Nebraska, and lots of cloud to ground lightning. After driving around a lot and not seeing much, we eventually saw a lovely discrete supercell develop in eastern Colorado. The storm quickly became tornado-warned and we soon had a view of the sculpted updraft. We settled on a spot in farmland between St Frances and Goodland, KS, where we watched the mesocyclone and disorganised wall cloud rotating in the fading sunlight. We did witness a very brief tornado, which generated a rotating column of dust from the base of the wall cloud - although it was hard to discern at the time, Ben’s time-lapse of the storm revealed the twister (it didn’t last more than 20 seconds). 

​All in all, it was a nice way to end what was an otherwise frustrating day on the High Plains.
Surface weather map, valid for 16:00 (Central Time) on the 25th May 2018. Much of the Central and Northern pains remained in a shallow warm sector, with a dryline extending south from south-central Colorado to Mexico. Storms were expected to develop in a corridor along the Colorado/Kansas border, where mid-level height falls would encourage severe storms to develop, including a few supercells.
Credit: NOAA/Weather Prediction Center.​

SPC convective outlook issued at 15:00 CDT. An Enhanced risk was issued for the Kansas/Colorado border. A 2% tornado risk was also issued in a corridor from Wyoming down to the Texas Panhandle.
Credit: Storm Prediction Center.

SPC hail outlook issued at 15:00 CDT. This illustrates how the Enhanced risk was issued for good confidence in a large hail event. Credit: Storm Prediction Center.
 Updraft and mesocyclone of the supercell we saw around dusk. I’ve no pictures of the brief tornado, unfortunately.
Angry skies between Goodland and St Frances. Lightning in the background too. 
Super-res reflectivity and velocity images for the storm(s) that developed to our west. A wind farm just ahead of the storm is providing the anomalous reflectivty and relocity returns. Credit: Radarscope.