The system we've been tracking since late last week will finally bring our first widespread severe weather of the year later tonight. Here is a look at the surface map from this afternoon. You can see the cold front to our west. Storms are expected to line up along and just ahead of the front this evening. Arrival time in the western counties of the Tri-State will be between 8-11pm, the line of storms should be along the Wabash River around midnight and over US 231 and the eastern counties of the Tri-State by 2-4am Thursday morning.
Here is the SPC's risk of severe storms for tonight…you can see the Tri-State is completely in the Slight Risk zone, meaning an elevated risk for storms with large hail and damaging winds.
Here is the probabilistic chart showing large hail (1" or great in diameter) for the event.
Damaging winds will likely occur early in the event, especially over Southern Illinois and far West Kentucky as the front arrives there tonight.
A tornado watch is already in place over Southwestern Illinois until 9:00 p.m. Here is the chart for tornado probability:
The biggest impact from this event will likely be heavy rainfall overnight and early Thursday. Localized flooding will be a concern, and smaller creeks and waterways may quickly rise in response to the storms. Here is the 48-hour potential rainfall for the Tri-State