Rain to begin late Monday morning and could lead to flooding, weather service warns

Rain will begin to fall this afternoon and become heavier tonight leading to the chance of localized street flooding, the National Weather Service said Monday morning.

The snow pack and deeply frozen ground will lead to rapid runoff. Local rivers and streams could reach flood stage, the weather service said in issuing a flood watch Monday morning.

"A frontal boundary will push into the area and stall, acting as a focus for multiple rounds of moderate to possibly heavy rainfall," the weather service forecast says.

Thunderstorms are possible in southeastern Wisconsin. 

"If heavy rain accompanies these storms, flash flooding becomes a concern," the forecast says.

"There is still some uncertainty as to just where the heavier rain bands will set up and how the icy rivers and ground will respond," the weather service said.

"For now, prepare for the potential of this heavy rain and possible flooding across southern Wisconsin during the Monday through Tuesday night timeframe. If flooding does occur, it would persist through much of the week ahead."

Travel could be difficult because freezing rain is possible from late afternoon through tonight, the weather service warned. Power outages are also possible.

"Plan for a slow commute this evening."

High temperatures of 39 degrees are expected Monday and a low of 34 is expected tonight. It'll be even warmer Tuesday, with a high of 47 degrees, the weather service said.

Further north, an ice storm warning was issued for this afternoon and evening for an area extending from Portage to Fond du Lac.

"Ice will make travel difficult, may damage infrastructure," the weather service warned in a tweet.

The hazardous conditions are expected to begin about 2 p.m. and extend into Tuesday in the affected area.