Peoria, Ill. — Severe storms ripped through the Midwest on Friday spawning deadly tornadoes across the Midwest and the south. As of Saturday afternoon, there have been 80 reported tornadoes, 440 damaging wind reports and 328 reports of large hail across the country. In Illinois, EF-2 tornadoes occurred in Sherman and Riverton while an EF-1 hit just outside of Rantoul. More tornadoes were reported across the state, but damage surveys were still being conducted.
As many communities across the state start to clean up, another storm system expected to bring more severe weather to the Midwest on Tuesday. On Saturday, the Storm Prediction Center expanded their 30% severe weather risk area (equivalent to a Level 3 Threat or Enhanced Risk) eastward for Tuesday afternoon and evening, and it now includes all of Central Illinois.
Models suggest a large, weakly capped, warm sector (area between the cold front and warm front) across the Midwest. A dry line is expected to be located near the Kansas/Missouri border and should act as an initiation point for strong long-tracked supercells early Tuesday afternoon. These storms would be capable of all hazards, including strong tornadoes.
It’s also worth mentioning, areas east of the dry line may see discrete supercells capable of all hazards develop where breaks in the cap occur, but exactly where these occur is not known. Forecasting where these discrete supercells develop is like trying to forecast where the first bubble in a boiling pot of water will develop, a very large boiling pot of water. There could be several rounds of these storms in the area before the main line arrives Tuesday evening.
The cold front should eventually overtake the dry line late Tuesday afternoon and evening in western Missouri sending a squall line capable of damaging winds and tornadoes into Central Illinois late Tuesday evening.
The CSU Machine Learning model shows an exceptionally high risk for severe weather over Central Illinois and the CWASP shows that the environment is going to be ripe for strong tornadoes.
CWASP is a combination of several different weighted parameters and gives us an idea of just how severe and event can be, particularly with tornadoes. When you look back at past tornado events, 75% of EF-2 or stronger tornadoes occurred when CWASP values were over 65. In other words, the environment is going to be primed for significant severe weather, it’s just a matter of figuring out exactly where it will hit.
I know a lot of us are getting fatigued of hearing about severe weather after last week, but it is imperative that you continue to monitor the forecast closely over the next few days. I promise our rhetoric and sense of urgency will not be like this for every event. It’s just unfortunate that we are looking at back-to-back significant severe weather events in less than 5 days.