Fri-Sat, July 9-10th Severe T'Storm Risk Update #1

​(10:00PM - 7/8/21) Multiple disturbances are expected to move through the region Friday and Saturday, bringing periods of severe t'storm potential to portions of the state Friday and Saturday.

Summary...
Multiple disturbances will eject out of the Plains, and push eastward across the Midwest and Mid-Mississippi Valley on Friday and Saturday. These disturbances will bring periods of severe t'storm potential to portions of the state, Friday and Saturday. There has been growing support within model guidance for a severe t'storm risk to extend into portions of the state during this period.

​Forecast...
Friday Afternoon - Friday Night, July 9th...
Scattered showers and t'storms will develop Friday afternoon across Iowa and Missouri, in the vicinity of a warm front. This activity will grow upscale into a few clusters, which will then push southeastward, affecting portions of Central and Southern Illinois later Friday afternoon through Friday night. The overall environment supportive of a severe t'storm threat will be in place across portions of Central and Southern Illinois. This environment will feature moderate instability of 1,500-3,000J/KG, dew points in the mid 60's to mid 70's, good shear, good forcing, and  modest lapse rates of 6.0-7.5C. This environment will be supportive of upwards of a an isolated to scattered severe t'storm risk (levels 1-3) across Central and Southern Illinois. Damaging winds and hail will be the severe weather threats, though an isolated tornado can't be ruled out.

Saturday Afternoon - Saturday Night, July 10th...
​Areas of rain and t'storms will be ongoing across Central and Southern Illinois Saturday morning, as well as adjacent portions of Missouri and Indiana. Some regeneration of this activity is possible, in addition to the potential for new development of scattered showers and t'storms Saturday afternoon, with all activity pushing east-southeastward across Central and Southern Illinois through the day on Saturday and Saturday night. The overall environment supportive of some degree of severe t'storm threat will be in place across portions of Central and Southern Illinois. This environment will feature moderate instability of 500-2,000J/KG, dew points in the low 60's to low 70's, good shear, good forcing, and  modest lapse rates of 5.0-6.0C. This environment will be supportive of upwards of a an isolated severe t'storm risk (level 1) across Central and Southern 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