Higher coverage of rain showers possible this weekend

 Most in the Stateline missed out on beneficial rain from Thursday night's storms, but never fear: We have more chances on the way this weekend in the form of a pair of upper-level disturbances coming between Saturday and Monday. Wind speeds a few thousand kilometers up are the main drivers of our weather systems known as the jet stream. Dips in the jet stream, or troughs, typically are the weather-makers, and a couple of them will traverse the Midwest over the next few days.

One of the things these troughs do is transport a lot of moisture in the atmosphere which will eventually fall as rain. One way we see this moisture is through a map showing precipitable water. This shows how much water vapor there is in a vertical column of air. Darker colors of green and blue indicate where the better-quality moisture lies. We will see a healthy amount of it lining up with the second trough between the Sunday-Monday window, but there is a lot of dry air just North, which may eat into rainfall totals across the Northern edges of the Stateline.

Futurecast depicts how these systems move through in the form of predicted radar. Our first shot at scattered showers arrives Saturday evening as the first weather system brings a warm front quickly followed by a cold front into the region. A few storms may be possible within this window as well. The better moisture and forcing arrive Sunday morning into the afternoon, reflected on Futurecast as more widespread showers. This would be our best window for picking up more of the beneficial rain through Sunday evening. Scattered showers them may be possible Monday as the drier air moves in behind the system.

 

All told, the better moisture between the two days combined will be down to our South across Central Illinois, but some spots in the Stateline may still be lucky enough to receive upwards of 1.0" of much-needed rainfall. Some of our Southern Wisconsin counties may see that drier air eat into those totals though, with the lower ceiling of 0.75" that direction.

One other thing this weather system will do is bring in a much cooler air mass to settle in across the region through next week. This will bring both afternoon highs and overnight lows back closer to average, with highs in the 70s and lows in the 50s most days next week. Spotty chances for rain may be possible early Tuesday, but we look to stay mostly dry then the rest of the week.