Mesoscale Discussion 1681 NWS Storm Prediction Center Norman OK 0932 PM CDT Sun Sep 06 2020 Areas affected...Eastern IA...Northern IL Concerning...Severe potential...Watch possible Valid 070232Z - 070430Z Probability of Watch Issuance...40 percent SUMMARY...Isolated strong/severe thunderstorms are possible across eastern Iowa and northern Illinois over the next several hours. Large hail would be the primary risk. DISCUSSION...Southern influence of upper Great Lakes short-wave trough will glance eastern IA/northern IL over the next few hours. Latest IR imagery suggests deeper convection is beginning to evolve ahead of the front with showers now evident from north of DVN into extreme southeast WI. This activity is evolving within a fairly moist, but capped boundary-layer environment where MLCAPE is in excess of 2000 J/kg. 00z sounding from DVN appears to have sampled this pre frontal air mass well, and strong capping is evident near 750mb. However, large-scale forcing for ascent along with a focused LLJ suggest sustained elevated convection may materialize along this corridor. Latest CAMs support this as well and there is increasing concern that a few storms may strengthen enough to produce hail. Will continue to monitor this region for possible severe thunderstorm watch.