The Arthur, Nebraska Supercell - 23rd May 2018

The 23rd May 2018 marked the first storm chase of the 2018 Chascation. We had waited patiently for several days prior to this event, as the weather had been quiet in the Plains since our arrival on the 19th. Our overnight hotel was in Hays, Kansas (a town that we would become accustomed to staying in due to is favourable central position in Kansas and proximity to I-70). The morning target was the town of Holyoke in north-east Colorado, where we thought we might be well positioned to catch any Trailing Charlie storms developing in the region. 

Surface weather map, valid for 15:00 (Central Time) on the 23rd May 2018. A warm front lifts slowly north across the Northern Plains, while a trough line lies north-south across the western high Plains and into Mexico. 
Credit: NOAA/Weather Prediction Center.

SPC convective outlook issued at 13:33 CDT. A slight risk across the Nebraska Panhandle and Northern Plains, mainly for large hail and strong winds. A 2% tornado risk area was also issued for the Nebraska Panhandle and Western South Dakota.
Credit: Storm Prediction Center.

We arrived at about 2:30 pm MDT, and after getting fuel, watched some aggitated cumulus begin to build all around us from a dirt track. After being questioned by several interested locals, we decided to chase a healthy-looking cell which had developed about 45 minutes to our north-west, in a similar location to where a couple of severe-warned storms had previously initiated. This turned out to be a good decision, as the growing clouds and outflow boundary soon prevented nearby clouds from developing any further. 

A full-on storm chase of about 3 hours then ensued. Wthout going into too much detail about the exact locations (since I was driving and have no idea where we went), we core-punched a high-precipitation supercell with 1-inch diameter hail, most likely somewhere to the south of Chappell, NE and Oshkosh, NE. Praise must go to the car and it’s 4-wheel drive and traction control system, which kept us firmly on the road with standing water and hail several centimetres deep all over it, 40-50mph crosswinds, as well as almost zero-visibility and hail and rain exploding over the windshield so loudly that we had to shout to be heard. We first stopped near the town of Oshkosh, Nebraska, where we watched our storm become increasingly disorganised. This was because a second thunderstorm was rapidly developing not far to the north-west, and this storm soon became dominant.

The first storm of the day developed behind some railroad tracks.

A second storm then developed to the north-west of the initial storm (above, which then soon decayed). This second storm would become the focus for the remainder of the day.

The road network around the developing storm was alarmingly poor, with very few paved roads to choose from, and often open countryside surrounding us, with no options for dirt road driving. We took state highway 92 south-east along the shores of McConaughy Lake, a desision which allowed us to drive ahead of the storm, and then drove directly north towards the town of Arthur. This decision was critical - although many other storm chasers had stopped to take pictures of a nicley structured supercell by this point, we knew that the window to remain ahead of the storm before it crossed the road ahead of us was rapidly closing - we did not have time to stop and find out how large dents the hail in the core of the storm would create on the car! By the time we got to Arthur, we were only about 5 minutes ahead of the storm - not enough time to stop, take pictures and get out safely. So we took an easterly route towards the community of Tryon. 

Action shot of the core of the supercell thunderstorm. Taken by Ben Pickering from the car at 60mph.

After driving east for about 15 miles in open countryside with few vantage points, since the rolling hills often blocked our line of view to the storm,  we lucked out to find a slight ridge on a dirt road, which gave us a view south-west towards the storm updraft. We were then in a perfect location to see the rotating and wind-sculpted updraft of the supercell thunderstorm. Further credit must go to Ben Pickering, for his expert radar analysis and steadfast navigational decisions, which got us ahead of the other storm chasers, and into a perfect location to view one of Mother Nature’s works of art. 

When we did stop to admire the beauty of the storm, we were graced with the presence of legendary storm chaser Mike Olbinski, who arrived after us to shoot at the same spot. He was incredibly gracious, and even offered to block the road with his team's cameras so no-one else could get in our shots. After introducing myself and complimenting him on his stormchasing timelapses, we had to quickly dive east once again, as the storm (with large hail and strong winds), had rapidly advanced on our position. 

For the next hour or so, we maintained our position ahead of the photogenic storm. Various other storm chasers joined us, with tails of having to drive through baseball-sized hail which dented their cars - we felt fortunate for having got through the storm unscathed! Towards dusk, we parked on a high ridge, and took some further photos as the storm became increasingly outflow dominated - eventually merging into a beautiful wind-sculpted severe squall line. The light soon faded and the storm began to die, so we decided to call it a day. This was an incredible storm chase; one which I will certainly never forget, and an epic way to kick-start (belatedly) our storm chasing trip! 

The Arthur Supercell 1.
The Arthur Supercell 2.
The Arthur Supercell 3.
Super-res reflectivity and velocity of the Arthur Supercell, from 20:40 CDT. Tilt 1. Credit: Radarscope.