Sun-Thur, Aug 8-12th Severe T'Storm Event Update #10

(10:00AM - 8/12/21) Several disturbances will continue to move through the region through tonight, bringing a continued severe t'storm potential to portions of the state, through tonight.

Summary...
Several disturbances will continue to move across the Plains, Midwest and Great Lakes through tonight. These disturbances will bring severe t'storm potential to portions of the state, through tonight. With this update we have upgraded portions of the state to a level 2 severe t'storm risk for today/tonight.

Forecast...
This Morning - Tonight, Aug 12th...
Areas of rain and t'storms have been ongoing across portions of Central Illinois this morning. Some of this activity is expected to continue, as it pushes eastward across Central Illinois into this afternoon. Another complex of rain and t'storms along the Missouri/Iowa/Illinois border area is also expected to push southeastward across Central Illinois, through this afternoon. Additionally, other areas of scattered showers and t'storms will develop across Iowa and Northern and Central Illinois this afternoon, which could form into clusters and spread southeast across much of the state this afternoon through tonight. An environment will be in place across the state supportive of a severe t'storm risk with this activity. This environment will feature high instability of 2,500-5,500J/KG, dew points in the upper 60's to low 80's, good shear, good forcing, and good lapse rates of 6.0-8.0C. This environment will be supportive of upwards of an isolated to sporadic severe t'storm risk (levels 1-2) across much of the state. Damaging winds, hail and an isolated tornado will be the severe weather threats.

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

​Recap...
Sunday Afternoon - Sunday Night, Aug 8th...
A large complex of t'storms that originated across Missouri spread northeastward across a large portion of the state, Sunday afternoon into Sunday night. Isolated to sporadic t'storms were severe with this complex, producing damaging winds. A few additional clusters of rain and t'storms moved across portions of the state Sunday night into early Monday morning, however none of this activity was severe.

Monday Morning - Monday Night, Aug 9th...
A large complex of t'storms that originated across Iowa on Sunday night, spread eastward across Northern Illinois Monday morning. No severe weather occurred with this activity. Additionally, a complex of rain and t'storms developed across Central and Southern Illinois Sunday night, which pushed across Central and Southern Illinois through Monday morning. No severe weather occurred with this activity. The main focus was Monday afternoon into early Monday night, as several supercell t'storms developed and moved southeastward across Northern Illinois. Scattered activity was severe, producing several tornadoes, and a few instances of damaging winds and hail.

​Tuesday Morning - Tuesday Night, Aug 10th...
A large complex of severe t'storms developed across Southwest Wisconsin and Eastern Iowa Tuesday afternoon. This complex of severe t'storms then quickly moved eastward across Southern Wisconsin and Northern Illinois Monday, later Tuesday afternoon into early Tuesday night. This complex produced scattered severe t'storms with widespread damaging winds, causing widespread tree damage and power outages across Northern Illinois.

Wednesday Morning - Wednesday Night, Aug 11th...
A complex of rain and t'storms developed across Northwest Missouri, Southeast Iowa and Western Illinois early Wednesday morning. This complex quickly moved northeastward across portions of Northern and Central Illinois Wednesday morning. This complex produced sporadic to scattered severe t'storms with widespread damaging winds, causing widespread tree damage and power outages across portions of Northern Illinois. An additional round of widespread rain and t'storms developed Wednesday evening into Wednesday night across portions of Northern and Central Illinois. Isolated to sporadic t'storms were severe with this activity, producing some instances of damaging winds and hail.

JP