Chase Log: May 14th, 2018 Arkansas City, KS Tornadoes

Another great chase day in 2018 started with very low expectations and resulted in two tornadoes in south-central Kansas northwest of Arkansas City, my third and fourth of the year and fifth and sixth overall.

Days like May 14th, 2018 are pretty common late spring/early summer days; a lot of instability with not much wind shear. This can lead to lots of storms that aren’t organized enough to produce tornadoes. On the morning of the 14th, I woke up to a Slight risk by the SPC with less than 2% tornado risk. I still had some hopes of a chase, so I paid some attention to how things progressed. By late morning, the SPC put a 2% tornado risk for eastern Kansas and western Missouri. I noticed a surface boundary of some kind (maybe the synoptic stationary front or an outflow boundary) moving slowly southward near Wichita, then stalling out. With a large amount of instability and a diffuse boundary of some kind, magic can happen. I figured in a slow year like 2018 I had to take my chances, so I left home around 1 pm to my initial target of El Dorado, Kansas. I got on the turnpike and saw some severe-warned storms to the east of Cassoday. I should note this was my first time in that area of the Flint Hills, and it was beautiful. I considered driving east towards the storms once I got to El Dorado, but there were some storms trying to form further south, near Winfield and Arkansas City. I thought these storms would have the best shot at having good structure at least. I arrived in Arkansas City as some updrafts were going up, but they were still competing for space. I found a good spot to watch things west of Arkansas City for a while. One storm started to look good, but a left-moving supercell developed and started to move towards it.IMG_0511

4:26 pm, a few miles south of Geuda Springs, Kansas, looking southwest. You can see the updraft base on the right (or north) side of the storm, meaning it had anticyclonic rotation, and posed no tornado threat. The storm wasn’t severe warned at the time, but it looked like it might contain some hail, so I wanted to sample the core. I drove through the tiny town of Geuda Springs, heading north, (where a turtle was in the road and a kid came out to grab it) and found a paved road heading north. I stopped at the Slate Valley Church four or five miles northwest of Geuda Springs where I awaited the heaviest precipitation. Sure enough, I saw some small hail after a few minutes, and I was fairly satisfied with my chase day.

A peculiar thing happened around this time; the left moving supercell merged with another storm to its north and became a right-moving supercell. I noted this on radar, and as I was in the core (north of where the updraft base would be) I headed back south towards Geuda Springs. I found a good spot to watch the storm for a while just west of town.IMG_0513

5:23 pm, just west of Geuda Springs, looking northwest. A nice updraft base is quite prominent here. I was beginning to have some hope for this storm, but there were other storms forming to the southwest that kept crashing into the big storm and disrupting it. I made a comment to my group chat at this time that I thought it would have a chance if other cells stopped merging with it. About ten minutes after this shot, another cell merged with it. I stayed at this spot, waiting to see what happened.IMG_0516.JPG

5:49 pm, same location. After the merger, another updraft base formed in about the same location. This one wasn’t as impressive as the first, but I had some hope still, as there looked to be one more merger coming up. If the storm could survive it, we might be in business.

After the merger, I headed northward now, as it looked like the storm was moving a bit north of due east. I stopped at the Slate Valley Church (again) and checked the radar on my phone. I was stunned to see that rotation in the supercell had rapidly increased. It appeared to have ingested a boundary of some kind, increasing the helicity in the near-storm environment. I could see a clear slot, but there was no visible rotation in the cloud base. My phone rang, and my phone said the call came from Wichita. The National Weather Service in Wichita called me to ask what I was seeing. I told them I saw on radar the rotation had increased, but I couldn’t make out any visible features of interest (like a wall cloud, funnel cloud). They thanked me and told me good luck, and I drove back south towards Geuda Springs. I found a good gravel road to stop on with a couple other chasers. I looked to my north and gazed upon an amazing sight.IMG_0519.JPG

6:09 pm, a few miles northwest of Geuda Springs, looking north. A wall cloud is visible less than a mile to my north. It was an incredible feeling, being so close to the center of the storm. The storm was strengthening rapidly at this point. My phone got an alert saying that the NWS had issued a tornado warning for that area.IMG_0520

6:11 pm, same location. There was visible rotation in the middle of the photo. There was even a funnel-wannabe at a couple points, but the storm seemed like it wasn’t ready to produce quite yet. I was lashed by rain as the rear-flanking downdraft pushed eastward, signalling a temporary end to the tornado threat. The storm was nearing the Arkansas River, meaning I had to pick a good river crossing to my east. I drove through Geuda Springs (again) and found a good road with a bridge heading east.IMG_0523.JPG

6:28 pm, just east of Geuda Springs. The small feature just above the cedar bush in the middle-left was something to keep an eye on. Sure enough, as I continued eastward, it developed into an impressive funnel. I found a gravel road to stop on a few miles northwest of Arkansas City.IMG_0525

6:35 pm, a few miles northwest of Arkansas City, looking north. Obvious funnel in the middle (obscured by a power pole). You may be able to make out a darker area in the rain where the tornado is touching down. I could see a swirling motion at the ground, so a tornado was in progress. Later, it was confirmed as an EF0 tornado that downed a few power poles. The tornado appeared to be weakening after a few minutes, so I drove eastward and found a spot to get a look into the storm as I came into Arkansas City. I could barely make out a tornado roping out in the heavy rain as I looked northwest. Turns out that this was a separate tornado, so that’s two on this chase. I drove east of Arkansas City, hoping to keep ahead of it, but the combination of terrain, bad road networks, and the fact that the storm appeared to have permanently transitioned to an outflow-dominant state made me decide to head for home.

For a day with almost zero expectations going in, this has to be considered a great chase. Hopefully there is more to come in the next few weeks.

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