“I fought the cap and the cap won,” one storm chaser said in the aftermath of Saturday, May 23.
I had been keeping tabs on what was looking to be a severe weather event during the afternoon of Saturday, May 23 nearly a week beforehand. The 2020 severe weather season has been notably quiet and I hadn’t had the opportunity to chase during prime severe weather season.
What looked like a sure set up in north central Nebraska then changed to western Nebraska, then eastern Colorado. Models were showing completely different set ups, giving me little confidence in a solid forecast.
As Saturday neared it seemed severe weather would break out along a dryline which stretched from eastern Wyoming, down through eastern Colorado and western Kansas. One worry which became clear was the strength of the cap.
The, “cap,” as it is known is a stable layer of warm air, warmer than the air below it, above the ground. It is the reason why thunderstorms always seem to break out in the late afternoon. It plays a crucial role in storm development, if the cap is too strong, storms might not develop at all, if it is too weak, the lone supercell you hope to chase might turn into a nasty line of storms.
On Saturday the cap looked particularly strong and it was debatable on where storms would form. One area which looked consistent was eastern Wyoming into the Nebraska panhandle. Models showed storms consistently in this region, but I had reservations about their potential to spawn a tornado.
Some models showed discrete supercells firing in central Kansas, but others show nothing at all, a total cap bust of chase. As the time drew closer I had no faith storms could breach the cap in this region.
I settled on a middle target, Sterling, Colo. Models had shown with some decent consistency discrete storms initiating in eastern Colorado and proceeding into southwest Nebraska. I gambled storms could breech the cap here.
This was my first time chasing outside of Nebraska, and hoped the whole trip would be worth it.
Proceeding into eastern Colorado, I set up at Sterling and waited for the atmosphere to do something. My confidence began to erode as late afternoon approached and little seemed to happen. A mesoscale discussion issued by the Storm Prediction Center said there was a chance storms could form in my area, but found it unlikely.
A patch of cumulus clouds seemed like it was trying to start organizing and I followed this complex east to keep up with it. Not far out of Haxtun, Colo., my fears came true. The cap was too strong for these storms and the meager updrafts seemed to be strangled, they withered and died without much fanfare.
I worried I had driven three hours into Colorado for nothing, the Wyoming storms were ongoing but were struggling in the low dewpoints and were too far away for me to catch up with.
I looked to the south and there were some larger thunderheads which were going up near Goodland, Kan., and were moving northeast. I thought I could intercept the storms as they moved further north, but they were over 100 miles away, a two hour drive.
I didn’t want to go home empty handed, so I thought, “in for a penny, in for a pound,” and pointed my car south in an effort to catch up with the storms.
After the two hour charge, I made a turn on Highway 36 and headed west, crossing into Kansas. By this point the lead storm was dying out, but the second one was showing a strong precipitation core. The possibility of tornadoes at this point was shot, but I still wanted to see what the storms would do.
Driving through the High Plaines was an interesting experience, with vast expanses between communities, large ranches and miles of barbed wire, it felt like something out of an older time.
Near St. Francis, Kan., I got an eye on the storm’s base and it seemed to be showing off low precipitation supercell characteristics.
An, “LP,” supercell is a true rotating thunderstorm, but are on the weaker side, compared to their classic and high precipitation peers. They contain light precipitation, which is well separated from the updraft of the storm, giving it something of a, “barber pole,” appearance.
The storm was clearly weakening, as the updraft became smaller and less defined. This was my first time witnessing an LP supercell, which as a storm chaser I took as a plus for the whole trip.
As the updraft withered away, the outflow from the storm became stronger. I was driving along when my car was violently jerked to the left, like it was kicked by a giant. I knew some weather phenomena was driven by the outflow of the storm and kept my eye out for anything suspicious.
Sure enough, I began to seem columns of dirt being kicked up and rotating close to the ground. These were, “gustnadoes,” and it was my first time seeing something like this.
Gustnadoes are small, short-lived vortexes which are driving by the downdraft and outflow of a storm. They can often fool storm chasers into thinking they are tornadoes, but in reality they have more in common with a dust devil than they do a tornado. The tell for gustnadoes is they are not connected to a storm’s base, like a true tornado is.
After watching several spin off into the distance and with the storm dying out, I called the chase quits and headed for home.
While I had higher expectations for this chase, and it was a complete bust in terms of witnessing tornadoes or severe weather, I still considered it worth the trip. Witnessing a dying LP supercell and several gustnadoes at the end of the trip made everything feel like it was worth it.