The Storm Prediction Center issued a mesoscale discussion for parts of the region with a 95% issuance of a Severe Thunderstorm Watch just before 3 pm. It is possible this watch will be issued just to the South of the Rockford area. Full discussion is posted below!
Mesoscale Discussion 0413 NWS Storm Prediction Center Norman OK 0237 PM CDT Mon May 14 2018 Areas affected...central/northern IL Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 141937Z - 142030Z Probability of Watch Issuance...95 percent SUMMARY...Severe thunderstorms are expected to develop across the discussion area the remainder of this afternoon with a risk for large hail and damaging winds. A Severe Thunderstorm Watch will be issued prior to 20Z. DISCUSSION...Latest visible imagery shows deepening cumulus in the vicinity of the front over central/northern IL at 1935Z, and modification of the special KDVN sounding for current conditions shows little remaining CINH. Thunderstorms are expected to develop and will likely become severe over the next few hours given an environment characterized by moderate surface-based instability and 40-45 kts of deep-layer wind shear. Damaging winds and large hail will be possible, and a Severe Thunderstorm Watch will be issued prior to 20Z.