I made a quick decision to chase a cold core setup in IL yesterday once I was done with class. Since it was a quick decision, and I have yet to get my laptop setup for chasing, I didn’t take the time to look at any surface observations, so it turned out to be what I call a “radar chase.” Honestly, I hate radar chasing, and yesterday was a perfect example of why. The storms that look the best on radar end up dissipating, and you’re left with nothing more than heavy rain. To add to the difficulty of yesterday, these were not traditional supercells, this was a cold core setup. So the tornadic storms didn’t even look impressive on radar.
As I was heading southwest on I-70, the storms approaching the southern tip of IL looked like the best bet. Once I got through Effingham, I did see towers going up to my north and west, and they actually looked fairly impressive. My concern with these was that they would soon cross the warm front and dissipate. So I opted not to go for them, and headed south to meet up with Rob instead.
Long story short, we got into a severe warned cell that probably didn’t even need to be severe warned. We witnessed some gorgeous mammatus, but that’s about it.
Taking a look at the surface observations this morning, I see that the tornadic storms (which were all near Springfield) were right at, or just south of the warm front. Here is a surface analysis at 2100z, 1-2 hours before the tornadoes.
This was an odd setup, with a warm front, stationary front, another warm front, and a cold front. I had done a little reading on cold core setups, and it highlighted the area south of the warm front and east of the surface low, east of the cold front. Having read that, I should’ve known the best position would be directly east of the surface low. The thought even crossed my mind, and I considered taking I-74 instead of I-70. But once again the SPC forecasts swayed my decision making. They seemed to really highlight southern IL, and even further south into MO, KY, AR, and TN. They did include west central IL in the tornado watch, however, so I guess they weren’t completely wrong.
Well that’s storm chasing. I’ve heard 1 in 10 chases on average results in a tornado. I have now been on 8 chases, so hopefully I’m getting close! This cold core setup was unfamiliar to me, so at least I learned something new, and the next time there is a setup like this, I’ll know where to position!