A complex set-up exists late this afternoon and evening for strong to severe thunderstorms in my southern counties, especially south of I-80 in SE Iowa and WC Illinois. The potential is complicated by the lack of robust heating but shear profiles and convergence are there for a few supercells towards evening. Low level hodographs are also enlarged and with any supercells that develop there is a risk of a tornado. Some of the hi-resolution short term convective models are showing a decent threat. In fact, the Storm Prediction Center has done a double upgrade increasing the tornado risk from 2 to 5 percent. The greatest chance for the strongest storms looks to be near HWY 34 south. While there are some strong indicators there are some negatives and this is far from a slam dunk. Will need to watch the trends the next few hours closely
The latest significant tornado outlook pin points southeast Iowa between 5 and 7 PM
This is the risk area from SPC. The enhanced region is where the chances for any tornadic storms resides.
This graphic was produce by the NWS in the QUad Cities.
Along with the severe weather aspect, heavy rains are possible where convection occurs. Rainfall rates of 1-2" per hour are possible in the strongest updrafts.
Already parts of the area have had excessive rain bands on the order of 1-3". Some areas near and east of Peoria may have seen as much as 6 inches. Flash flooding is a real risk in local spots.
Heavy rain looks to be an issue on an occasional basis into the middle of next week. A very unusual pattern for the end of September. Roll weather...TS