Isolated shower/storm chance for the holiday weekend

 

The chance for rain and thunderstorms will return to northern Illinois and southern Wisconsin as we look towards the holiday weekend, but it won't be a complete washout and there should still be plenty of dry hours to get out and enjoy.

For the remainder of Thursday evening, skies will continue to fill with cloud cover as a cold front sinks south across the Midwest. Temperatures Thursday afternoon warmed into the upper 80s and low 90s, reaching 92 degrees in Rockford. Under the partly to mostly cloudy sky Thursday night, low temperatures will dip into the upper 60s - rising into the low to mid 80s Friday afternoon.

Friday morning will be our first chance for rain heading into the extended weekend as showers and a few thunderstorms are expected to develop along and ahead of the cold front. No severe weather is expected with the front coming through during the morning, but a few pockets of heavier rainfall are possible. As the cold front passes through early afternoon, an isolated shower or storm may still occur during as some moisture lingers around behind the front. It does appear that most areas remain dry, however, heading into Friday evening.

High pressure is quick to build in Saturday, but with the position of our jet stream overhead Saturday and Sunday, several loosely organized upper level disturbances are expected to move through the Midwest. This is known as a 'ring of fire' pattern. Heat and instability build under a strong ridge of high pressure where sinking air dominates and doesn't allow for the development of rain or thunderstorms. On the outer edge of the ridge and right along the heat dome, however, thunderstorms develop and follow the flow of the jet stream, feeding off of the heat and instability to the south. This type of pattern is very typical for July and August and often leads to more nighttime thunderstorm activity which produces very heavy rainfall and strong winds. With the heating of the day, a couple isolated showers and thunderstorms may develop this weekend. However, there looks to be many more dry hours than rainy/stormy ones through the weekend. High temperatures will warm into the middle and upper 80s.

The 4th of July itself may actually hold our best chance for rain through the weekend, which could come towards Monday evening and overnight. A little more of an active storm pattern looks to develop heading into next week with a ridge of high pressure building across the Plains, placing much of Wisconsin and Illinois under the favorable storm track for low pressure systems to move along. Timing these types of systems can often be difficult, especially several days in advance. But the latter half of Monday appears to have a slightly higher chance for rain/storm activity that could carry over into Monday night. While it's too early to cancel any plans for the day, you'll definitely want to pay close attention to the forecast for Monday. The rain and storm chance will remain with us into early next week.