(9:45PM Friday - 3/4/22) A storm system moving through the region will bring a severe t'storm risk and a period of high winds to portions of the state and region, Saturday afternoon through Sunday morning.
A strengthening storm system will move from the Plains Saturday morning, through the Midwest Saturday night, and then through the Great Lakes by Sunday morning. This storm system will bring a severe t'storm risk and a period of high winds to portions of the state and region, Saturday afternoon through Sunday morning.
With this update we have slightly expanded the isolated (level 1) severe t'storm risk a bit further east across Northwest and Western Illinois.
Saturday Afternoon - Saturday Night, March 5-6th ~ High Wind Episode:
A strengthening storm system the region will bring a period of high winds to the state, Saturday afternoon through Sunday morning. High winds aloft, characterized by a low level jet (850MB) of upwards to 50-70KT and 925MB winds of 40-55KT, will be in place. Adequate mixing is anticipated at least up to 900MB, along with strong warm air advection ahead of the storm system and cold air advection behind the storm system, which will aide in transporting higher winds to the surface. During this period, wind gusts of 35-50MPH are expected across much of the state, Saturday afternoon through Sunday morning. Isolated wind gusts of 50MPH+ will be possible across Northern Illinois Saturday night through Sunday morning. Winds Saturday afternoon into Saturday night will be southerly, winds from Saturday night through Sunday morning will be westerly.
Saturday Afternoon - Saturday Night, March 5-6th ~ Severe T'Storm Episode:
The main risk for an isolated severe t'storm risk will exist across portions of Northwest and Western Illinois, Saturday evening through later Saturday night. While a few isolated showers and t'storms will be possible Saturday morning and afternoon across portions of Northwest and Western Illinois, the min focus will come later. A line or two of rain and t'storms will develop across Minnesota, Iowa and Missouri this afternoon, along and ahead of an advancing cold front. This activity is expected to sweep eastward across much of Northern and Central Illinois, Saturday evening through later Saturday night. Ahead of this activity, an environment will be in place supportive of some severe t'storm risk with this activity. This environment will feature low instability of up to 1,000J/KG, dew points in the mid 50's, good shear, good forcing, and good lapse rates of 6.0-8.0C. This environment will be supportive of upwards of an isolated severe t'storm risk (level 1) across Northwest and Western Illinois. Damaging winds, hail and an isolated tornado will be the severe weather threats.
Below are the severe t'storm and high wind forecasts for this event.