I wasn’t really expecting too much this far north today in the way of severe weather. The early morning Day 1 outlook had southern Illinois in a moderate risk and the slight risk was just north of there. It appeared that the front was going to pass through quickly, taking all the severe weather with it to the south and east. Looking at the surface map, there was quite a temperature gradient so I knew something was up. Dewpoints were in the upper 50s and forecasted to hit the lower 60s. Convective parameters weren’t too shabby with CAPE values around 1500 and helicity around 200-250. The cap wasn’t a concern today with such a strong front, but clouds were definitely an issue. If we remained socked in with clouds, we probably wouldn’t get much severe weather. However, if we could get a few breaks it would be a different story.
During the morning, we had several little areas of storms move through the area. None were severe, but there was decent amounts of lightning. After each batch went through, the sun would seem to make another appearance. The 1630z Day 1 pushed the slight risk much further north and the moderate wasn’t too far behind. Watching satellite loops of the region, you could definitely see some destabilization occurring. A little after 11:00am, the SPC issued an MCD for central MO to IL stating that storms were expected to rapidly develop after 12:00pm. About an hour later they issued a tornado watch mainly west of I-55 in IL to central MO. Around 1:00pm, a cell had fired up east of Quincy, IL and was rapidly gaining strength. Numerous severe and tornado warnings were issued for it as it tracked across western and central IL. It appeared to take a right turn and head more east than its previous northeast direction. At 3:52pm, a tornado was reported with this cell in Clinton, IL.