Let us begin by taking a look at the weather scenario that Michigan is about to face with a major winter/spring storm.
I believe the best way to get started is with a radar forecast for tonight through Wednesday night. Simply looking at the forecast animation a few times will give you an idea of the bad weather that is on its way.
The next storm will move through Michigan overnight tonight. For at least the northern two-thirds of Lower Michigan, the first six to twelve hours will be completely winter-like.
By mid-morning Wednesday, the winter weather will move to far northern Lower Michigan, while southern Lower Michigan will begin to feel thunderstorms brewing.
A major severe thunderstorm outbreak is then possible Wednesday evening. The Storm Prediction Center (SPC) has already become aggressive in its approach to potential severe storms.
I’ll go into greater detail about each aspect of the storm throughout the day. Let’s start with a general idea of where and how much winter weather to expect. Then we’ll move on to the early forecast of severe thunderstorms and tornadoes.
This is the most accurate snowfall forecast we currently have. Anywhere from Grand Rapids and Flint northward could see one to five inches of snow within a few hours. A heavy three to six-inch snowfall is possible from Baldwin and Cadillac to Houghton Lake and Harrison.
After the snowfall, there will be sleet and freezing rain for about an hour or two. While northern Michigan is still reeling from the weekend ice storm, this shot of freezing rain should only total one-tenth of an inch.
Now comes the much more dangerous part of the storm: a warm severe thunderstorm warning between 5 p.m. and 11 p.m. Wednesday.
I know many of you are still recovering from the severe thunderstorms that hit Sunday. I’ll give some of us some good news. We refer to the severe weather outbreak as a “conditional” severe weather chance. All of the major severe weather factors are present, with the exception that it may remain cloudy on Wednesday. Thunderstorms may not be severe in areas where the weather remains cloudy and cool. I’ll have more on that later this morning or early afternoon, once we deal with the upcoming winter weather advisory.
So, here are the Storm Prediction Center’s severe weather predictions for Wednesday evening. The black hatched pattern indicates the area where “significant severe weather” is possible.
The severe wind gust forecast indicates that all of Lower Michigan may experience quick, damaging thunderstorm gusts. The southern half of Lower Michigan, particularly the area south of I-94, should be concerned. The black hatched area indicates that gusts of 75 mph are possible somewhere.
We anticipate a lot of low-level wind shear with this storm system. Tornadoes are caused by low-level wind shear during severe weather outbreaks. Tornadoes are expected in the southern half of Lower Michigan at a rate of 5%. Fortunately, the black hatched area on the tornado forecast is far to our south.
Remember: this is a “conditional” severe weather situation. If you see warm sunshine Wednesday afternoon, you should be on high alert. If it stays cloudy and cool, we’ll probably avoid widespread severe weather.
At the moment (5:30 a.m.), it appears that Grand Rapids, Flint, and all areas north of this line will remain cloudy and cool. I believe we may be able to avoid severe thunderstorms in Michigan’s central region. South of Grand Rapids and Flint, it appears to heat up and become unstable. The southern third of Michigan is most likely to experience severe weather.
This provides you with a general update on what I’m calling a 1-2-3 punch storm–snow, freezing rain, and severe thunderstorms.
Many updates await fellow Michiganders. We’ll get through this storm, but you can stay updated at MLive.com/weather. You can also download the MLive app for your iPhone or Android phone.
I provide live coverage of severe weather outbreaks. The MLive app will notify you when I begin broadcasting live. Make sure you allow notifications from the MLive app.
Our next round of good computer models is usually ready by 10 a.m. Watch for an update on snow and freezing rain first, followed by a closer look at the potential severe thunderstorm outbreak.
