A strong push of warm, unstable air ahead of low pressure moving north from the Central Plains to southeast Minnesota tonight will set off scattered to numerous thunderstorms over southern Wisconsin. This will be the beginning of several periods of thunderstorms with the potential for heavy rainfall from tonight through Monday night as, first, a warm front lifts through southern Wisconsin as the low deepens over Minnesota and Iowa, followed by a cold front that will track from west to east across the state Monday night.
Here are graphics that depict expected rainfall across southern Wisconsin and all of Wisconsin through Tuesday. The heaviest rainfall over portions of southern Wisconsin is expected tonight into early Monday and again Monday night.
Rainfall totals across southern Wisconsin range from around 1 inch in the far southeast to just over 2 inches in the northwest.
Click Here to see the Hydrologic Outlook that is in effect for southern Wisconsin.
There is also a Slight Risk of severe thunderstorms later this afternoon and tonight, as well as on Monday into Monday evening. Large hail and damaging wind gusts will be the main threats. Below is the SPC outlook for today and Monday:
The probability for seeing heavy rain is predicated on seeing repeated rounds of slow-moving thunderstorms over the area. A change in the timing of the system or the location of frontal boundaries in the region could alter the total amount of rain at any one location. Stay up with the latest forecasts for updated information on the heavy rain and severe weather potential.
National Weather Service - Milwaukee/Sullivan