2026-02-19 EVENT: IL/IN/KY

[Dan Robinson]

The first viable tornado chase opportunity looks to be on our doorstep, a typical Midwest winter event where a significant wave manages to bring moisture northward under one of the cool season's many potent shortwaves. Dewpoints reaching 55-60F will wrap into a surface low with the classic arc of supercells blooming to the southeast of the low. Models have been slowly improving the thermodynamics of this setup, leading to sufficient low-level instability to support a respectable tornado threat on par with many similar events we've seen in this region between December-February in the past.

CAMs have been rather messy with this event, depicting multiple waves of storms beginning in the late morning near St. Louis and tracking generally northeast along the I-70 corridor into Indiana. While the I-70 depictions would make for a convenient chase, what typically happens with these is the more classic arc of supercells setting up from Peoria through Mount Vernon, with the northern cells in the arc more favored for tornadoes (closer to the surface low vorticity and better low-level turning). However, the core of the jet has been shown farther south, and storm motions should be more easterly in these regions. CAM UH tracks are also not as useful in these setups, as I expect that any discrete storm will have a healthy low-level meso (not just the I-70 storm that the HRRR wants to highlight).

I'm not sure I buy the viability of the early storms, as they could be more elevated/across the boundary. I'd be leaning more toward the later-firing cells to the west as the better plays. We'll also need to watch the look of the dry slot at the morning's first satellite image - a good one will of course portend a better result. My feeling right now is to stage between Vandalia and Effingham to hedge for the morning activity, then leave those and get into position slightly SW of there for the main round later.

 

[Andy Wehrle]

I would be all in on this setup if there was better model agreement on the shortwave coming through in time to cool off the mid-levels over top of the moisture tongue during peak heating. It might still happen, but it's far from a guarantee. I have tomorrow and Friday off so I'll be looking at tomorrow morning's observations/CAMS ready to bolt out the door.

 

[Jeff House]

If I lived in STL or Indy I'd give Thursday a try. No travel for me but it could be a day with reasonably good visibility for early season, and perhaps somewhat sculpted cells - especially the back line if two lines form.

Looks like first thunderstorms develop mid-afternoon, but they could be elevated and a little messy. Most CAMs have a second line just to its west late afternoon. Later in the season I'd go after a convergence zone east. This one, I'm thinking closer to the TP and that second batch farther west.

Agree with Dan that the north side of the arc may be more rewarding. It will have the low-level shear on the boundary. This T/Td they could be nice sculpted low-tops. UH tracks are noted with beefier cells south. I believe that's a function of CAPE and upper-level jet.

 

[Jeff House]

Good morning it's game day! Already got stuff going in Missouri which complicates the plan. Nothing like more questions in the morning than on the day before.

Most CAMs hold this Missouri stuff together all the way to Ohio. They also develop a dominant cell or two on the south end of it by late afternoon. Unfortunately the forecast latitude of the said cell(s) is all over the place. Fortunately we can just follow the east-west boundary's latitude.

I still favor whatever redevelops behind. That's a bit of a gamble on the Atmo recharging. This would be a much easier chase out of Indianapolis. While driving west, watch the leading cells just in case. Then at some decision point in Illinois, decide on them or to keep moving west.

Out of STL is more complicated. Follow what's going on now or wait until much later for re-development? I'm sure Dan has a plan but I'm writing for others in eastern MO and western IL.

Follow the first east, with option to turn back west, risks getting too far east late in the day to return to western cells in time. Waiting on new development pretty much scratches any attempt farther east. I guess I'd lean toward follow the first batch until about central Illinois. Then it's the same decision point as I have in the Indianapolis paragraph. West would just be a U-turn vs continuation.

Too tough to call right now. Low level shear might be slightly better east, but the cells could be a mess. West target is greater risk but perhaps greater reward. Guess I'd eat lunch in east-central Illinois and decide from there.

 

[Sean Ramsey]

I'm not chasing today but if I were my first inclination would be to target the southern end of the blob and hope for the best. I'd have some concerns about re-development so close to sunset, and given the distance I'd have to drive to get there from the west I'd be focusing on the daytime storms in the eastern target. As Jeff mentioned though, it could be messy and hanging on too long could put you in a tough spot for the later show, if there is one.

Good luck to those who are out today!

 

[Dan Robinson]

Not as optimistic this morning. It feels cold, there isn't a nice dry slot and surface flow isn't robust. I know it will improve later though. I still like the western storm idea, but models aren't as optimistic and we'll likely run out of daylight for that round. I'll likely stay with the lead storm for a while. If it has a good look, I might try to stay with it into Indiana. I'm not expecting that to be the case though. If the CAMS are right, it will be well south of the Interstate and impossible to keep up with.

The storm SW of STL looks like that's going to be it. I do like that has slowed a little and turned in the past 2 hours.

 

[Dan Robinson]

Early stuff is garbage, easy decision to bail on it. I already like the look of the western Cu field, we may get a storm there much sooner than expected.