Wed-Thur, July 28-29th Severe T'Storm Episode Update #2

(9:30AM - 7/28/21) A storm system moving through the region today and Thursday will bring severe t'storm potential to portions of the state, this evening through Thursday night.

Summary...
A storm system will move from the Northern Plains into the Midwest today, and will then push eastward across the Great Lakes on Thursday. This storm system will bring severe t'storm potential to portions of the state, this evening through Thursday night. Little to no change was needed to forecasts with this update.

​Forecast...
This Evening - Tonight, July 28th...
Areas of scattered showers and t'storm have been ongoing across portions of Northern Illinois this morning, and this activity may continue into the afternoon for some areas. The overall severe t'storm risk with this activity is low, but wouldn't rule out an isolated severe t'storm being possible. The main focus will be this afternoon and evening across portions of Minnesota and Wisconsin, where of scattered showers and t'storms are expected to develop in the vicinity of a storm system advancing southeastward. This activity is likely to grow upscale into one or more clusters, which will then push southward across Wisconsin, Western Michigan, Northern Indiana and Northeast Illinois from this evening through early Thursday morning. 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, 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.
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Thursday Morning - Thursday Night, July 29th...
Clusters of rain and t'storms from Wednesday night may be 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