Good morning and happy new year!
A wintry mix and snow will move in this afternoon. Starting off the new year with an impactful storm system.
Timing:
Freezing rain will arrive along the I-94 corridor around 12pm. By 2pm, the precipitation will reach I-96, mixing with sleet and snow initially. After 4pm, light freezing rain and freezing drizzle should occur with temperatures 30 to 32 and a fairly deep layer of warm air aloft. This should last through about 8-10pm, before changing back to sleet and snow. Snow is likely between 12am and 3am before ending tonight.
From Grand Rapids to Alma, northward, this will mainly be an all snow event. 2-4 inches of snow is expected. Along and south of I-96 a mixture of sleet and freezing rain is expected, with a period of light freezing rain likely during the late afternoon and evening. This freezing rain should result in at least minor accretion on objects such as power lines and trees. This is not a major ice storm, but enough to cause travel problems with icy road conditions. Temperatures remain below freezing all afternoon and into tonight. Additionally, power outages are possible. The more ice there is, the higher the potential for power outages. It doesn't take much ice to cause hazardous travel conditions. Winds will also be gusting to around 25 MPH during the afternoon and evening, which could aid in downed power lines and trees with the weight of ice on them. On a widespread basis, a glaze to 0.1" of ice is likely, but amounts of 0.2" to 0.25" locally are possible if conditions become just right. There is a risk for sleet mixing in, which would hold some areas to lesser amounts of ice. Either way, need to watch areas between I-96 and I-94 very closely this afternoon and evening into tonight for ice to occur, followed by 1 inch of snow towards midnight, combined with gusty winds and temperatures remaining at or below freezing.
Roads will likely become icy after 12pm today and remain hazardous through at least Saturday morning. Power outages are possible, especially between I-96 and I-94. Again, this is not a major ice storm, but any amount of ice is dangerous for travel conditions, especially for areas that locally see the higher end of the potential ice amounts. Stay tuned for updates later this morning and during storm for the latest information.
Here is a video further breaking down the details. This was created at 11:15PM 12/31/20: