Rainfall between 1 and 2 inches is expected tonight. Combined with the snowmelt from today's warm temperatures, it will create an elevated risk of flooding of small streams and rivers from 7 tonight through Wednesday afternoon.
A slow-moving cold front and associated strong low pressure will bring heavy rain tonight. In addition to a very moist air mass in place, the cold and — in some cases, frozen ground — will result in higher-than-normal runoff.
Rain will change to snow on Wednesday afternoon as temperatures drop below freezing.
The forecast for the Grand Haven area:
Tonight: A chance of showers before 8 p.m., then showers and possibly thunderstorms after 8 p.m. Some of the storms could produce heavy rain. Widespread fog, mainly between 8 and 9 p.m. Low around 35. Breezy, with a south wind 16 to 21 mph becoming northeast 7 to 12 mph after midnight. Chance of precipitation is 100 percent. New rainfall amounts between three-quarters and 1 inch possible.
Wednesday: Rain showers before 8 a.m., then snow likely. Some thunder is also possible. Temperature falling to around 29 by 4 p.m. Breezy, with a west wind 7 to 12 mph becoming west-northwest 17 to 22 mph in the afternoon. Chance of precipitation is 90 percent. New snow accumulation of less than 1 inch possible.
Wednesday night: Snow showers likely. Mostly cloudy, with a low around 18. Windy, with a west-northwest wind at about 30 mph, with gusts as high as 40 mph. Chance of precipitation is 70 percent. New snow accumulation of around an inch possible.