January 3, 2023

Tuesday, January 3, was not on my radar as a chase day until the morning of the event. Noticing the local 2% on the morning convective outlook prompted me to check out what was happening on the numerical forecast models.

What I found was an alluring cold core setup with several analogs to 1 December 2018. At the surface, a low was moving over Iowa with a warm front (red) extending eastward across Northern Illinois. A diffuse cold front (dark blue) over Missouri was moving east, but ahead of that, a surface trough with a tighter moisture gradient (light blue) was forecast to push into central Illinois by midafternoon. This boundary looked like it would be the focal point for convective development. The winds ahead of it were backed slightly east-southeast, shifting to southwesterly behind the boundary, creating a wind shift line of favorable surface vorticity without the undercutting of a sharp cold front.

Surface temps in the low 60s F and surface dewpoints barely 60 F were pretty marginal for a robust severe weather event, but still attention grabbing for January.

It was the temperatures aloft that would more than make up for marginal conditions at the surface. A closed 500 mb low was moving over the Siouxland area, and, in 1 December 2018 fashion, a lobe of super cold air aloft extended well eastward over the far northern end of the warm sector. It was a cold core tornado play. My target was just off the surface trough/moisture boundary on a favorable gradient of colder temps aloft to the north and warmer, moister air at the surface to the south. The actual warm front didn’t look like it would be in play, too far removed to the north and cool at the surface for robust surface based storms. I set my target at Taylorville, IL around 20-21z.

Afternoon SPC Mesoscale analysis plots highlighted this target with a combination of very robust 0-3km CAPE and favorable surface vorticity along the boundary. These plots had me scrambling to get my gear ready for a chase. The pattern was ripe for low topped yet discrete storms with strong, rotating low-level updrafts.

The first Tuesday of the month, it was also the monthly outdoor warning siren test. I drove up to the north side of town and found a quiet spot in a park to shoot the 10 am test. It was a good practice run for the chase later in the afternoon as it made me realize how unprepared I was, with cameras and gear in various states of disarray.

The target was close enough that I could just hold at the house and watch the situation unfold. The morning clouds cleared and temperatures warmed into the 60s, making me anxious to get on the road and chase some spring-like thunderstorms. Clusters of showers started to initiate east of Saint Louis. I watched them struggle to get going, and this kept me from racing out the door after them. As they drifted east of 55, I realized I’d have to intercept them near Effingham at about dark, and I let this target go, instead waiting for something closer to home and my original target.

By 2 pm I could see percolating convection to my southeast and decided to hit the road. I went east out of Springfield down I-72, just far enough to get downstream of some of the more promising looking towering cumulus. I took the exit for Illiopolis/Mount Auburn, about 10 miles west of Decatur, and pulled off onto a gravel field access near the highway ramps, which I’ve probably used several other times before on other chases. And there I waited. For what, I wasn’t sure. At this point, and watching the sluggishly building convection, I thought I was probably just going out to see some pretty rain showers. A tornado was a long shot, but the possibility was there so I had to try.

Clusters of showers extended to my west and north, slowly gaining intensity on the radar with 40 dbz returns. A rainbow with a faint double lit up the winter sky to the north-northeast.

The cell just to my west finally started to emerge as the winner from the bunch, continuing to build while taking on a nice cellular shape. An updraft base and gust front extended southward from the precipitation core, something like a real storm that I could watch, but I still wasn’t expecting much.

A suspicious looking bump protruded from the base well south of the main precipitation core. I was slow to get a tighter shot of it, and even after a couple minutes of it taking on a more pointed funnel like appearance, I was still reluctant to believe I was looking at a legit funnel cloud.

The funnel quickly descended while I was training the camera and zooming in on it. I was pretty far away from it, at least a couple miles, but the AX100 has a sharp lens and the lighting was great, so I held my ground to watch it from afar. A truncated cone funnel extended from the base in shades of teal, backlit against cloud layers, and the sunbeams and orange skies of a winter’s late afternoon.

A classic cone funnel emerged, half way condensed to the ground. I realized I better try to report this as the process had been ongoing for minutes now. The Storm Prediction Center had decided against issuing a watch, the risk too isolated and marginal. And there was no warning on the storm, what still looked like not much more than a rain shower on the radar. I used the Spotter Network feature on my phone’s RadarScope app, forgetting that our local NWS office doesn’t really look at Spotter Network reports. I saw on my screen that another chaser had already sent in basically the same report.

The funnel narrowed and wavered like it was beginning to rope out, gorgeous in the late daylight.

As it roped out, the vortex tightened up for one last show, condensing nearly all the way to the ground. Likely a weak tornado at this point, it was reported to the weather service as such by other spotters.

The weak tornado reportedly moved through a field where it had no impact that could be surveyed. It was logged EFU or Unknown on the Enhanced Fujita scale.

It roped out as a helical hollow tube. Amazed and energized by what I had unexpectedly witnessed, it took me a few moments to realize that probably wasn’t just a one-off fluke rain shower funnel and I better switch into active storm chasing mode. The chase got real, real fast.

My phone finally went off for a TORR (confirmed tornado) tornado warning. I went north into Illiopolis without really planning my route, picking roads by sight and hoping that they went through. Emerging from town, it was obvious I was looking at a legit supercell now with a rounded, horseshoe shaped updraft base and rear flank downdraft clear slot. The storm was starting to drift off to the northeast, and I raced to catch back up.

I turned east once I was about even with the storm’s longitude and had a long through road. Another bowl lowering was visible southward down the storm’s gust front to my east-southeast, and it was soon apparent that the next cycle's funnel cloud was developing.

A wispy point condensed halfway to the ground. The funnel was displaced well south of the storm’s main updraft, an evolution similar to the first funnel.

I continued eastward to maintain my view and hopefully get a bit closer. A long truncated tube took shape. It looked quite a bit more robust than the first funnel, yet I couldn’t really make out debris or a dust cloud at ground level, so I reported it as only a funnel cloud via Spotter Network.

I stopped at an intersection to get a zoomed shot and watch it for a few moments before proceeding eastward. The funnel probably had a surface based presence and may have been a weak tornado, but I couldn’t confirm it. It roped out a minute later with accelerating, twisting motion.

I paused after the rope out before continuing to stair step in the storm’s wake. Looking northeast from behind the storm’s rear flank gust front toward the main updraft:

Tornado warnings continued as I entered Macon County. I turned north as the storm began to sport some gorgeous classic structure with a sculpted base.

More stair stepping east and north, as the storm’s base looked ominously dark while bowing out into a large horseshoe.

The forward flank started to dump precipitation, and the rear flank gust front fanned out with whale’s mouth structure. I thought the storm was gusting out with cold air and may be done at this point. The colors and textures were gorgeous though, and the storm had an impressive run that exceeded my expectations, so I was totally cool with this.

I was wrong, however. Turning north again, the base reorganized with what looked like a robust wall cloud and low level rotation.

A large funnel cloud took shape before I could pull over and get my dashcam on it. It was a truncated cylinder, centered within an impressive cyclone aloft. A much more robust tornado looked imminent. The storm was moving away from me, and my contrast wasn’t amazing, so I decided to try to get a tad closer before the tornado fully formed. I raced north and took the next crossroad east.

A classic looking cone started to condense and I quickly pulled over to get a shot. The previous funnels had been displaced from the main updraft well southward down the gust front. This funnel, however, was collocated with the main updraft, and I suspected a more significant tornado was developing as a result.

The funnel changed shape rapidly as I tried to get a tighter shot.

Now pretty much fully condensed and the most robust funnel of the day, I confidently reported this one as a tornado via Spotter Network.

The tornado was receding to my northeast. I didn’t realize how close it or I was to the town of Maroa at the time. The funnel cloud lifted, but then the camera barely caught large airborne debris in the moments before I pulled away to catch back up with the storm.

I went east then turned north on US-51. Traffic slowed, and I should have been expecting it, but I was still surprised to see debris in the road as I crossed the tornado’s damage path. I found out what the large debris was that my camera had captured: A grain bin rolled nearly into the road, the top laying a ways away, and the adjacent fields were littered with light debris. These were not merely cold air funnel cloud curiosities, but legitimately threatening tornadoes.

I began stair stepping again, while the tornado warnings and supercell structure was ongoing. My light was rapidly fading, however, the sun setting before 5 pm. The storm also appeared to be accelerating to the northeast and I was having trouble keeping up. Lightning was meager and rather than screw around with low topped cells in the dark I decided to call the chase. I stopped on the grid to get once last peek as the storm moved off to the northeast toward Weldon.

Another chaser vehicle had been tagging along with me since before the Maroa tornado, and as I suspected it was Chuck and Carrie Haskin. I had given them a heads up about the setup before I headed out the door, and I was happy to see they had gone for it and caught the show in time. We chatted about the day before saying our farewells. I took 54 southwest back to Springfield, making sure to avoid the Maroa damage path and ongoing tornado warnings in the line to the south.