A deepening low pressure system will track through southern lower Michigan tonight. This powerful storm will have a variety of impacts across lower Michigan, inluding wintery precipitation, heavy rain, gusty winds, thunderstorms and a risk for severe weather. Gulf moisture will lift up through the Mississippi valley ahead of this storm. The colder air that is in place across Michigan will hold steady, forcing the warm moist Gulf airmass to ride over the shallow cold air. As a result some snow will continue up north and transition to sleet and rain. Areas south of a Muskegon to St. Johns line are expected to see surface temperatures warm enough for just plain rain through tonight. Further north though, a prolonged sleet event could occur, through tonight. Considerable uncertainty exists with whether the airmass will be cold enough to keep the precipitation as sleet and/or snow, so stay tuned to the latest forecasts.
The precipitation will be heavy at times and thunderstorms are likely, especially tonight. A slight risk for severe thunderstorms exists tonight mainly south of a Holland to St. Johns line. Large hail and Damaging winds will be the primary threat. Many areas are likely to see in excess of an inch of rain with over two inches possible. In addition east winds could gust to over 35 mph this afternoon and evening. Those gusty east winds will become westerly on Wednesday as the storm pulls away.
Rivers levels will be on the rise as we go into the middle to end of the week as the runoff from the storm works its way downstream.
Below is the latest severe weather outlook through tonight
Below is the latest rainfall forecast through tonight
As for Wintery Weather into tonight, the map below highlights the area most likely to see some impact