06/15/2026
Long read folks, but we explain everything for you:
The storm prediction center has a level 3 risk for severe weather this Wednesday already. This is pretty significant being three days out. Let’s lay out the facts:
1. This is a powerful storm, typically more of a March-April set up. A strong 986-990 mb low pressure will move to our NW, putting us in the warm, unstable sector.
2. This system will usher in a warm, moist, unstable airmass. This will make the environment conductive for severe weather.
3. Shear will be absolutely incredible, especially for June standards. A powerful mid-level flow of 70kts will be compounded with a powerful SW low-level jet of 50-55kts. This is a textbook example of what a high-end tornado outbreak may look like. Any time a powerful spring-like storm occurs in summer, we get nervous.
4. Now, let’s hit the breaks; because holy smokes, the set up we have is not what we enjoy seeing but that doesn’t mean we will guarantee see major severe weather. Let’s look at limitations:
Limitation 1: Storm mode. This will probably be the most impactful factor for the tornado situation. If storms blossom fast and cluster, then this could be more of a linear event which means widespread damaging winds and spin-up tornadoes. If storms stay more discrete, then that would pose more of a risk for long-track tornadoes that could be intense. That’s not hype, that’s the fact. Now, some good news is we do see signs that storms will cluster up quickly. We want that. We’d rather have widespread damaging winds than long-track, strong tornadoes. Storms probably will initially be discrete as they’re developing so there will be a window we want to watch, but we’re not quite sure where that will set up. For now we recommend everyone watches closely, particularly central and northern IL.
Limitation 2: Morning convection. We know there will be morning storms and clouds. Typically this would hamper severe weather, but given this is a powerful storm in June, the atmosphere can recover fast. Now, storms could linger longer than anticipated, we saw this last Thursday in northern IL. If storms linger into mid-afternoon then that could limit coverage and severity somewhat, but it won’t be enough to end it. If storms move out before lunch, then we will be worried at that point. We’re waiting for high resolution guidance to come in.
Limitation 3: Warm front placement. This is the big question. Where does the warm front set up? Where that sets up is where we’ll see instability and moisture pool, leading to a locally high chance for tornadoes. North of that warm front it’ll be more of a damaging wind and hail risk, weaker tornadoes too. Along that front is where we will see higher tornado risk. Right now central IL is favored for it, I-80 south to I-70(a narrow corridor somewhere in that region). It’s possible morning storms limit the northern progression of that front too, which could keep it closer to I-70. That’s a question we don’t have answered yet.
Now, this is a lot of info to process. So we recommend you follow for updates.
Our goal is to lay out the set-up so you can understand what we see.
As usual we’ll update, and join our group to see other forecasts: Illinois Storm Community
