The Final Chase - 7th June 2018
Chase day 19 (7th June) was our last full chase of our epic storm chasing trip of 2018. A slight risk was issued by the SPC for discrete supercells initiating off and just to the east of the western Rocky mountains of Colorado and Wyoming. A stationary front was situated across the region, and this was also expected to provide a focus for some marginally-severe storms to develop. Starting the day in Brush, Colorado, we drove north-west into Wyoming, targeting a discrete storm that developed close to Chugwater.
WPC surface analysis for 10:00 CDT. A stationary front lies across the Central and Northern Plains, with dewpoints in the high-50s to low-60s Fahrenheit for the target chase area. Credit: Weather Prediction Center. 
SPC convective outlook, valid for 15:00 CDT. A slight risk was issued where the greatest probility of significant severe convective winds and large hail was expected. There was also a 2% tornado risk issued for all of eastern Wyoming and the Nebraska Panhandle. Credit; Storm Prediction Center. 
There was some fun driving on dirt roads once again - I was driving at the time, and remember the car constantly looosing and gaining grip on the soft sandy roads. It doesn't take much on these roads - especially when driving quickly - one lapse of concentration or slip of the steering wheel - to have a huge accident. The storm initially appeared to be splitting visually, although we later determined that the two updrafts we could see were more likely separate storms developing on a weak outflow boundary. However, the storms never remained very discrete, as separate cells constantly appeared on radar, competing for low-level moisture and shear. 

After watching these updrafts do very little for close to an hour next to a mosquito-filled field on some dirt road close to the town of La Grange, we decided to head east into Nebraska, chasing after a slightly more discrete storm about 20 miles to our south-east. The storm ultimately produced a lovely shelf cloud, which we chased east, to the south of Scottsbluff. We ended up near to the Courthouse and Jail Rocks, impressive buttes overlooking the North Platte valley. Here we watch an impressive lightning display as the shelf cloud passed gracefully overhead. Timing the shutter right, we snapped some incredible pictures of the lightning striking around the buttes. My favourite, and incredibly lucky shot (below), is of a huge CG which struck less than a kilometer in front of us - no doubt a strong positive strike, as it tears the sky open from the top of the cloud.

Our retreat to the car was soon warranted, as a barrage of cloud-to-ground lightning strikes soon fell left, right and centre around us. The closest strikes were around 200 metres away, with a brilliant flash soon followed by a the distinct “crack, crack, crack” sound as very close thunder ripped through the air. The sun set right behind the thunderstorm, whose orange disk could be sen through the rain shaft, and which set the entire storm ablaze with an ethereal orange glow - one final, fitting tribute to Team Volatility’s tour of the Great Plains in 2018. 
Super-res reflectivity and velocity images of the thunderstorm to the south-east of the town of Scottsbluff, in the Nebraska Panhandle. The storm wasn't even severe-warned! The lightning photo below was taken just to the south of the town of Bridgeport. Credit: Radarscope.
Positive cloud-to-ground lightning strike with Courthouse and Jail Rocks in the foreground.
Cloud-to-ground lightning strike in-between the Courthouse and Jail Rocks.
One of my last images of the trip: a well-striated shelf cloud over a classic American road stretching off to vanishing point.