Tue-Wed, April 27-28th Severe T'Storm Risk

(11:45AM - 4/27/21) Multiple disturbances will move through the region today through Wednesday, bringing a severe t'storm risk to much of the state, tonight through Wednesday night.

Summary...
With a trough in place across the Western US, multiple disturbances will eject out into the Central US, moving through the region today through Wednesday. These disturbances will bring a severe t'storm risk to much of the state, tonight through Wednesday night. Model guidance has been firm on an isolated to widely scattered severe t'storm risk across Central and Southern Illinois for Wednesday and Wednesday night. However, within the past 12-18 hours an isolated severe t'storm risk also appears likely across Northern and Central Illinois, tonight into early Wednesday morning.

​Forecast...
Tonight/Wednesday Morning...
A cold front expected to slide southward across Northern and Central Illinois tonight and a disturbance will be moving through. Scattered showers and t'storms associated with this disturbance across Iowa and Missouri this evening and early tonight will spread across Northern an Central Illinois overnight, with some additional development possible as well. This activity will then continue through Wednesday morning. An environment featuring instability of 2,000-3,000J/KG, dew points of 58-65, good forcing good shear and even mid level lapse rates around 8C is expected to be in place. Given the aforementioned environment expected, this will set the stage for an isolated (level 1) severe t'storm risk across Northern and Central Illinois, tonight into early Wednesday morning. Hail will be the main threat.

Wednesday/Wednesday Night...
A front is expected to be draped across Southern Illinois on Wednesday, with multiple disturbances expected to move through. Several wave of showers and t'storms are expected to move across Central and Southern Illinois, Wednesday morning through Wednesday night or early Thursday morning. An environment featuring instability of 1,000-2,500J/KG, dew points of 64-71, good forcing good shear. Given the aforementioned environment expected, this will set the stage for an isolated (level 1) to widely scattered (level 2) severe t'storm risk across Central and Southern Illinois, Wednesday morning through Wednesday night. Hail and damaging winds will be the main threats.

Below is the severe t'storm forecasts for this event.

JP