Wed-Thur, July 28-29th Severe T'Storm Episode Update #3

(11:00PM - 7/28/21) A storm system moving through the region through Thursday will bring severe t'storm potential to portions of the state,tonight through Thursday night.

Summary...
A storm system moved from the Northern Plains into the Midwest today, and will push eastward across the Great Lakes on Thursday. This storm system will bring severe t'storm potential to portions of the state, tonight through Thursday night. With this update we have adjusted tonight's forecast based on real time observational trends, and little to no change was needed for Thursday's forecast.

Forecast...
This Evening - Tonight, July 28th...
As expected, widespread showers and t'storms developed late this afternoon across portions of Eastern Minnesota and Northern Wisconsin. This activity congealed into a loose complex, and has been pushing southward across Northern and Central Wisconsin this evening and early tonight. This complex is expected to continue to move southward, eventually pushing into and across Northern Illinois overnight tonight and into early Thursday morning. An environment is in place that is supportive of a severe t'storm risk with this activity. This environment features high instability of 3,500-5,500J/KG, dew points in the mid to upper 70's, high shear, ample forcing, and high lapse rates of 7.0-8.5C. This environment will be supportive of upwards of an isolated to widely scattered severe t'storm risk (levels 1-2) across portions of Northern Illinois. Damaging winds and hail will be the severe weather threats, though an isolated tornado can't be ruled out.
​
Thursday Morning - Thursday Night, July 29th...
Clusters of rain and t'storms from tonight will ongoing Thursday morning across portions of Northern Illinois. In the wake of this early day activity, a new round of scattered showers and t'storms is expected to develop Thursday afternoon along a cold front moving southward across Central Illinois. After development, this activity will push southward across portions of Central and Southern Illinois Thursday afternoon into Thursday night. An environment will be in place supportive of a severe t'storm risk with this activity. This environment will feature high instability of 3,500-5,500J/KG, dew points in the low to upper 70's, modest shear, modest forcing, and modest lapse rates of 5.5-6.5C. This environment will be supportive of upwards of an isolated severe t'storm risk (level 1) across portions of Northern Illinois. Damaging winds and hail will be the severe weather threats, though an isolated tornado can't be ruled out.

​Below are the severe t'storm forecasts for this event.

JP