Active pattern begins today, strong storms possible Thursday

It's quite remarkable to think that our average high doesn't hit 70° until mid-May, and yet Rockford has witnessed six 70° days in 2024.

That is now the most on record through March 12th since records began in 1905. 

Temperatures remain rather warm for Wednesday, though tagging along with today's warmth will the start of what is to become an active pattern.

Following last night's weak disturbance, a ridge of high pressure will briefly settle in. This will leave most of the daytime hours, especially to start, dry. As we jump into the afternoon, clouds will increase, turning skies mostly cloudy. Not too far behind that will be a chance for a few widely-scattered showers and an isolated thunderstorm.

Again, temperatures will end up unseasonably warm compared to mid-March standards. However, not warm enough for a third 70° day. 

A round of showers and storms will develop over the Midwest this evening. This is what we will have to keep an eye on for tomorrow morning as forecast models lift this activity into the area.

By the time they enter the Stateline, they will have likely be in a weaker state, posing a risk for heavy rainfall and small-sized hail. Now, there is still time for the forecast to change. With that being said, the stuff that passes through during the morning will play a huge role into the late-day threat. 

If the morning activity comes through with more intensity than what models are showing, this would toss the afternoon threat into the garbage. Why? Lapse rates and instability would take a hit. But also, this will help keep the warm front that we've talked about in prior updates well south of the area. 

If this activity manages to weaken and we do end up seeing a sizable break, this will allow the warm front to creep closer to I-88, increasing the potential for severe weather locally. Concerns would include large hail, following by heavy rain, strong winds, and an isolated tornado. From what I saw from forecast models this morning, it's going to be tough for the warm front to lift into north central Illinois. Plus, the northeasterly flow north of the front will also make things difficult for any organized convection. Again, something to monitor this afternoon and overnight tonight. Rain should carry on into the early stages of Friday, tapering off before mid-day. Highs will briefly hit the 50° mark.