As we first mentioned last Tuesday ( Impressive Storm System Next Week? ), a strong storm system by August standards is on the way to the Region. Unfortunately, there isn’t much clarity as of this Sunday evening post in terms of how EXACTLY this storm system will play out. It all hinges on the amount of instability Monday afternoon in the atmosphere above us.
SEVERE THREAT MAP
As of Sunday night, the Storm Prediction Center has highlighted the best chance for severe weather from south-central Illinois into west-central Indiana. I could see this threat area shifting a bit to the north in the next update if we get two things:
- An initial round of rain that has a small, unimpressive coverage area
- Partial sunshine at some point during the day
TIMING OF THE STORMS
This is always the last thing that gets figured out, but as of Sunday night it looks like we’ll see two “main” rounds. The first moves through earlier Monday with just rain and embedded thunder. It’ll likely be OFF OF what we’re seeing develop in Missouri right now. This is the round that will determine how the afternoon/evening storms shape up.
If we see longer lasting morning/early afternoon rain–we’ll have a low risk for severe weather late Monday.
If we see a quick dose of morning/early afternoon rain as we see some sunshine during the afternoon–we’ll have a higher risk for severe weather late Monday.
It ALL depends on that morning/early afternoon round of rain.
Here’s what our model says. I’m taking it with a grain of salt, because it’ll likely change:
It shows a dry morning followed by strong to severe storms in the afternoon and evening.
It brings another round in here along the actual front late tomorrow night into Tuesday morning.
BEHIND THIS FRONT?
Cooler, drier air won’t punch in here right away. Tuesday looks showery, windy, and still a bit humid before drier air works in late Tuesday into Wednesday and Thursday. But it’ll be here and you’ll feel it!
And here are our lingering rain chances Tuesday as the system wraps around over us:
We’ll see showers and storms tomorrow, but the main focus is around how strong they’ll be. The potential is there for severe weather, but it all hinges on our atmosphere’s ability to become unstable throughout Monday afternoon ahead of the actual cold front. Heavy rain is a sure bet as we’ll have a ton of moisture up above us. Cooler, drier air won’t arrive right behind the front, but will move in by Wednesday and Thursday.