5:56 Saturday, April 29, 2023
A significant spring/winter storm will bring additional heavy amounts of precipitation in the form of rain and wet snow to northern Wisconsin and also to far northeast Minnesota from tonight through Sunday night and lingering into Monday in northern Wisconsin.
This system will also produce strong north winds across the entire Northland the next few days with the highest wind gusts occurring near Lake Superior especially along the North Shore from Duluth to Grand Marais where a Wind Advisory is in effect from 4 AM Sunday to 4 AM Tuesday with wind gusts of 45 to 55 mph possible. The strongest winds are expected to occur Sunday night into Monday. Tree limbs could be blown down and a few power outages may result. A few trees may be uprooted from the combination of very saturated soils and strong wind gusts.
Travel could be very difficult to impossible at times from late tonight through Monday along the South Shore (higher elevation inland from Lake Superior) in northern Wisconsin, east of the city of Superior. Heavy snow loads on tree branches could result in downed branches.
Duluth area — The best chance for some wet snow will occur early Sunday morning (mainly before 8 AM) with snowfall accumulations of less than an inch expected. Otherwise expect occasional rain showers to continue through Sunday night.
Note — There is a chance for snow totals of up to 24 inches in a few locations in the 10-18″ zone in northwest Wisconsin.
Expect much lower snow totals near the immediate shoreline along the South Shore of Lake Superior with the more significant snow totals favoring the higher elevation in the Arrowhead of Minnesota, but more so in northwest Wisconsin along the South Shore.
Here’s my snowfall forecast through 7 PM Monday.
Additional precipitation amounts of 1 to 3″+ are expected in northern Wisconsin where northerly winds crossing Lake Superior gives a boost to the system driven precipitation.
NAM 3km model radar forecast through 7 AM Monday.
Snow (blue)
Rain (green)
NAM 3km model wind gust forecast through 7 PM Monday.
A look at our developing system this afternoon over the Great Lakes via Goes-16 satellite imagery.
Visible loop ending 5:16 PM CT, Saturday, April 29, 2023.
Water vapor loop ending 5:21 PM CT, Saturday, April 29, 2023.
Temperatures aloft are already cold enough to support snow in northeast Minnesota and northwest Wisconsin this afternoon, but as is always the case with these late spring snow events, it all comes down to temperatures closer to the surface as to whether or not precipitation is in the form of snow or rain as precipitation reaches the surface, and those temperatures near the surface will remain borderline to support all snow during the duration of this event, with a more likely scenario being periods of wet snow and other times where the snow mixes with and changes back over to rain. The exception to this may be in the higher elevation inland from Lake Superior where temperatures could remain just cold enough for mostly snow from late tonight through Monday.
This will be a very slow-moving system as low pressure which was over far southern upper Michigan late this Saturday afternoon moves into southeast Ontario but not until around daybreak on Tuesday.
A strong upper-level system will also remain over Great Lakes region through early next week.
Tim
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