A strong cold front is moving through Michigan this afternoon and tonight. Eventually fairly cold air will settle over Michigan by Sunday morning.
Saturday morning will be chilly, but Lower Michigan won’t worry about frost. Saturday morning will have clouds and wind, both factors that keep temperatures from plunging.
Sunday morning will be a different story. Skies will clear Saturday night, and the wind will die off. Sunday morning will be the chilly to cold morning depending on your location.
I want to show you three different temperature forecasts so you know the risk to your plants.
First let’s look at the forecast produced by human beings. Yes we real people still get to put input into forecasts. It’s not all computer driven. The forecast below is made by the National Weather Service offices in Michigan, after they look at all of the data. It’s usually the best forecast.
Sunday morning low temperature forecast from the National Weather Service
In looking at the forecast above, frost would be a worry from Clare northward. The populated areas of the southern half of Lower Michigan will not have frost based on this forecast, but just chilly morning temperatures. The interior section of northern Lower Michigan will have frost or freezing temperatures. The fruit growing areas along the water around Traverse City and Leelanau County should be okay with temperatures in the mid-30s.
But the human forecast doesn’t always show the bottom-end possibility for temperatures. So let’s look at two computer models.
Sunday morning low temperature forecast from the North American Model (NAM)
The image above comes from a short-term model that usually is pretty accurate on cold mornings. It shows the chance of light frost in low-lying spots down into the Lansing area. If you see a temperature forecast of 35 degrees it would be cold enough for spotty light frost. So the scenario out of this model would say folks along U.S. 127 should think about covering plants that are very frost sensitive.
Finally let’s look at the low temperature forecast from the European Model. It just gives us another feel for what the lowest temperatures may be Sunday morning.
Low temperature forecast for Sunday from the European Model.
The Euro isn’t quite as cold as other models. We will use this one and just see which way the trend goes over the next 48 hours. If the other models trend toward the Euro, we know the threat of spotty frost is lessening in the Lansing area. If the Euro trends toward colder, we know you’ll need to cover your frost sensitive plants in the Lansing area.
With any of the temperature scenarios, the Detroit area, Ann Arbor, Flint, Saginaw, the Thumb, the Grand Rapids area and Kalamazoo should not have frost.