StansWeather.net

I had been watching this day on the models for awhile now and was anxious to see what would happen now that it was finally here. The early morning Day 1 (06z) outlook painted a small moderate risk area from extreme SW IL to SE MO. This was the general area I was wanting to head to, so I was pretty excited. Unfortunately the moderate risk didn’t last long as the SPC downgraded it to a slight risk, stating that the risk of severe weather didn’t warrant a moderate risk. (blah!) Dewpoints were only forecasted to be in the mid-50s, while helicity values were looking much better around 200-300. I won’t even talk about CAPE since it was nearly non-existent. 😉 The CAP from the ILX and SGF 12z soundings was pretty high, so stuff was not likely to fire up until sunset or thereafter. Despite the limited ingredients, Darin and I decided to give it a go and see what happened. Our target area was the chasing hotspot of SW IL, better known as Pinckneyville, IL. 🙂

Darin and I left my place here in Champaign at 11:00am and headed south on I-57. Not much was going on with the weather at this time, just some partly cloudy conditions and very windy. We stopped south of Salem, IL at a rest stop to take a break from the non-stop driving. Inside they had a weather monitor that showed temps, radar, and a few other things. There appeared to be a small squall line that had developed just west of us, but we had no intentions of chasing it. After grabbing a Pepsi and some Potato Skins (great chaser snack food!), we continued south on I-57. We arrived in Mt. Vernon around 1:30pm and decided to look around for a computer w/Internet access to get some weather data. After going 0 for 2 at the local Staples and Radio Shack, we explored the main drag for the town library. Once we found it, we went inside and asked about using a computer. We were very happy that all we needed was a driver’s license to use the computers.

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.