Thunderstorms are likely to return to the Stateline Wednesday afternoon as a cold front moves in from the northwest late Wednesday night/Thursday morning. Ahead of the front both moisture and temperatures will increase, holding on to the heat and humidity for the afternoon. However, temperatures Wednesday will be determined on how quickly cloud cover moves in during the morning. For most, temperatures will rise into the upper 80s and low 90s, but the heat index for some could reach the upper 90s, to near 100 degrees. This would be especially true for areas southeast of Rockford.
The atmosphere will have a cap, or lid, on it during the morning, but that cap will begin to weaken early afternoon as thunderstorms are expected to develop rather quickly. While not widespread, scattered thunderstorms are likely to develop locally Wednesday before forming into a line of storms stretching from northeast Illinois into central Illinois. It’s there that more widespread severe thunderstorms are possible.
Any storms that do develop would be capable of producing locally damaging wind gusts, along with the risk for heavy downpours and frequent lightning. The storms will be coming to an end Wednesday evening with only a few lingering showers sticking around through early Thursday. Winds will shift around to the northeast Thursday with drier skies expected through the start of the weekend.
The Ogle County Fair kicks off Wednesday and will run through the end of the weekend. If you’re going to be out at the fair Wednesday, make sure you stay updated with the forecast. Once the cold front passes, skies should remain dry through the start of the weekend with the next chance for thunderstorms either late Saturday night or Sunday.