A morning round of severe thunderstorms producing small hail and creating power outages moved through Champaign-Urbana and surrounding areas just before sunrise this morning. This sets the stage for what is likely to be an active 48 hour period over much of the region.
We here in Champaign-Urbana should see a lull in the thunderstorm activity for a good chunk of the day today. I expect the next round of strong to severe storms to erupt in portions of Missouri - near St. Louis early this afternoon. These storms could eventually expand in coverage and progress into central Illinois during the late afternoon hours, into the overnight. This is when I expect CU to see the next potential for severe weather - likely in the form of damaging winds or large hail. While the situation is fluid and ever-evolving, I expect the next round of storms to hold off until after 4 PM today, likely after 7 PM.
Overnight, as storms move into central Illinois from Missouri we'll see the potential for several rounds of thunderstorms overnight. The threat from these storms again, will likely be dangerous lightning, large hail and perhaps damaging winds. Flooding could become a concern in areas that see multiple rounds of thunderstorms.
Tomorrow is the wild card. Thursday has the look of a widespread severe weather event across almost all of Illinois, but there are still some big question marks. It appears the instability/fuel needed for severe thunderstorms will be present in the form of a warm and humid airmass, aided by some spring-time sunshine during the afternoon. The question mark is whether or not the directional wind shear is present in the atmosphere that is required to make the thunderstorms rotate - and ultimately create the potential for tornado development. Right now, the computer forecast models do *not* suggest that adequate wind shear will be present for a widespread outbreak of tornadoes across central Illinois. That said - with a potent and dynamic system such as this, widespread strong to severe storms are still a good possibility, and large hail/damaging winds are nothing to laugh at. However, at this time I do not anticipate a major tornado event. Should anything change to even remotely suggest this as a possibility, I'll be sure to sound the alarms.
Here are the Day 1 and Day 2 severe weather outlooks from the Storm Prediction Center, highlighting their biggest threat areas over the next 48 hours.