(11:30AM - 3/25/21) A storm system will move through the region today into Friday, bringing a severe t'storm threat to the southern half of the state and high winds to Northeast, Eastern and Southern Illinois.
A storm system will move from the Mid-Mississippi Valley and Ohio Valley as it rapidly strengthens today/tonight, and then push into the Great Lakes by Friday morning. The northern side of a larger and more significant severe t'storm risk to the south will reach into the southern half of the state, with a severe t'storm threat expected this afternoon through this evening. Additionally, a period of high winds are expected across Northeast, Eastern and Southern Illinois, this afternoon through early Friday morning.
Areas of rain and isolated t'storms have spread across portions of Southern Illinois this morning, as a warm front lifts towards and into Southern Illinois. In the wake of this early activity and with the warm front continuing to lift northeast into far Southern Illinois, a lower end environment will develop. This low end environment will feature low instability, modest moisture and great shear. Additional areas of scattered showers and t'storms that develop along and ahead of cold front across Missouri and Arkansas during the afternoon, will spread across the southern half of the state this afternoon through this evening. Given the aforementioned low end environment in place, a severe t'storm threat will exist with this activity, with isolated to widely scattered severe t'storms being possible. Hail, damaging winds and an isolated tornadoes will be possible with any severe t'storm.
In addition to the severe t'storm potential, high winds are expected this afternoon through Friday early morning, across Northeast, Eastern and Southern Illinois. High winds aloft, characterized by a low level jet of 40-65KT, will develop as the associated storm system rapidly strengthens as it moves through the region. Mixing depth will be limited, but will be enough to support wind gusts of 25-45MPH and 40-60MPH across portions Northeast, Eastern and Southern Illinois, this afternoon through Friday early morning. Isolated power outages and minor tree damage will be possible for areas affected by the higher end winds.
Below is the severe t'storm and wind forecasts for this event.