The southeast Wisconsin, Waukesha and Milwaukee forecast for the rest of your Sunday night has that front just to our north, so I can't rule out the slight chance of a sprinkle or light shower late. Overnight lows will botton out in the upper-30's under partly to mostly cloudy skies. Most of the night will be fine.
Monday will be mild with a cool front slowly approaching the area. Most of the day should be okay, but I can't rule out a sprinkle or light shower in the morning. Highs will top out in the mid-50's for Milwaukee's temperature and lakefront communities before falling there and low-60's for Waukesha's and inland temperatures.
Monday night should start off okay, but as the night goes on and that cool front starts rolling in, rain will develop overnight. The rain will not be heavy. Overnight lows will bottom out in the low-40's.
We should see some rain mixing with snow at times on Tuesday night. There may be some light snow accumulation for a few folks that night. Lows will bottom out around freezing.
Wednesday looks dry and there will be a slight chance of a shower Thursday with highs slowly creeping back up into the 50's. There will be small chances of rain then next weekend with temperatures then getting close to 60.