Posted: Jan 9, 2020 / 03:59 AM ESTUpdated: Jan 9, 2020 / 03:59 AM EST
Let me start by saying we have a chance of a major ice storm across parts of Lower Michigan. I’ll begin with the heavy rain/flood threat. Above is the Flood Watch for N. Indiana, NW Ohio and far S. Lower Michigan. This is not the only area that will see heavy rain and flooding. This is from the N. Indiana NWS. They say:
"Widespread moderate to heavy rainfall will develop Friday evening and continue into Saturday evening. Rainfall amounts of 2 to 4 inches are likely across the watch area with locally higher amounts possible. * Flooding of low lying areas and along small creeks and stream is most likely. In addition significant river flooding is likely to develop this weekend and extend into much of next week."
Here is the NWS Graphic showing the area in orange that will get the heaviest rain. The Flood Watch is from Friday evening thru Saturday evening for the time when it will be raining. A general Areal Flood Warning will follow, along with Flood Warnings for specific rivers.
Rivers are already high. As I write this early Thu. AM – the Grand River in G.R. has a flow of 10,700 cubic feet per second – compared to an average flow of 3,240 cfs. So that’s more than 3 times the average flow for 1/9. The St. Joseph River has a flow of 5,930 cfs compared to an average flow of 3,240 cfs and the Kalamazoo River at Comstock has a flow of 1,600 cfs compared to an average flow of 773 cfs.
The Hydrologic Outlook from the Grand Rapids NWS says:
"People living in flood prone locations should monitor forecasts this week on this developing hazardous weather situation. Now is the time to think about preparedness and plan for impacts in the event the heavy rainfall and flooding materialize."
Heavy rainfall of up to 4″ would send these rivers significantly above flood stage, perhaps even to record high levels for the month of January.
There is a Lakeshore Flood Advisory for Bay, Huron, Sanilac and Tuscola Counties for strong northeast winds Saturday and Saturday night. The wind goes back northwest later Saturday night into Sunday and at that time there could be another period with a Lakeshore Flood Advisory for West Michigan.
This storm will be adding a lot more water to Lake Michigan. At a time when the water level of Lake Michigan is often falling slowly, it’s unfortunate that levels will be staying high during the mid-winter.
Here’s links to the National Weather Service Forecast discussions for Grand Rapids (West Michigan), N. Indiana (includes the Michigan counties that border Indiana), White Lake/Detroit (SE Michigan), Gaylord (N. Lower Michigan and Chicago/Romeoville (NE Illinois)….current Michigan weather observations and a Michigan weather map. Here’s Regional Radar:
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