Widespread Rainfall Likely for the End of the Weekend and Early Next Week

Widespread rainfall will be possible for the latter part of the weekend and into early next week.  Low pressure moving through southern Illinois Thursday night will continue to spread rainfall up through central and east-central Illinois and Indiana through Friday morning.  Skies will remain mostly cloudy Friday and Saturday as another low pressure system develops in the Plains late Saturday afternoon and evening.

Warm air ahead of the low will spread north across Illinois Saturday night, bringing rain showers into northern Illinois and southern Wisconsin, but a light mix further north across central and northern Wisconsin Sunday morning.  Moisture being pulled from the Gulf of Mexico may be just enough to allow heavy rain to fall across the Stateline through Sunday afternoon.  Rainfall totals could be heavy, between half an inch to an inch, depending on how much moisture is pulled north.

The heaviest rain should be coming to an end by Sunday evening with scattered showers likely lingering into Monday afternoon.  A second, and possibly stronger, low pressure system will develop over the southern Plains and lift northeast Monday night into Tuesday.  This low will pull even more moisture north with it, potentially leading to more widespread rain through Tuesday night.  Forecast models, however, don't necessarily agree just yet on the overall track of Tuesday's low.  A more southward tracking low would keep the heaviest rainfall to the south (along with any thunder potential) but a more northward track would likely bring the highest rainfall totals into northern Illinois.

Once the cold front passes Tuesday night, winds will increase from the northwest pulling down a much cooler air mass.  This will push temperatures into the low 40's for highs towards the middle to end of next week and lows back into the 20's.