UPDATED 9PM - Flash Flood Warning Madison Wisconsin
Update 900PM - Flash Flood Warning in Madison tonight with the worst of it on the west side. Radar estimates showing 6.0"+ rainfall accumulation with an additional 2-4" possible. Significant flooding is occurring with reports of stranded cars. Highway 12 through Madison is shut down. "Streets have turned to rivers".
830AM - The National Weather Service has issued a Flash Flood Watch for sections of southern Wisconsin until 9:00am Tuesday. This includes the cities of Madison and Milwaukee.
Low pressure will slide across northern Illinois over the next 24 hours producing rain and thunderstorms north of the low track. Like last week's heavy rain event, this system will be a slow mover. Thunderstorms may become stationary producing locally heavy rain exceeding 3.0". Overall confidence is low. The best chance for heavy rain seems to be along or south of I94. Rain is less certain across central and northern Wisconsin, perhaps a scattered chance at best.
Here is the latest regional radar loop