Slushy snow is possible in the southern half of Minnesota on Saturday, but just how much falls is the big question as a storm system is now just 48 hours from arriving.
In short, the storm system is set to bring a low-pressure system through central Iowa with rain and snow possible on its cold side – that's Minnesota, to the system's north.
The National Weather Service writes Thursday morning that "it does not appear cold enough" overall – temps in the 30s and 40s – for the storm to produce widespread accumulating snow, but there could be a narrow band of heavy snow somewhere in the southern half of the state with "better chances" in southeast Minnesota and southern Wisconsin.
At this same time yesterday, all indications were that any slushy accumulations would be much further north, from the Mille Lacs Lake area into northern Wisconsin. Things have changed and they could change dramatically again.
A warm ground and a pretty strong late-April sun mean this storm is going to have to be impressive to overcome everything that doesn't support accumulating snow at this time of year. Most computer models don't suggest it'll be cold enough to support widespread plowable snow, but the NAM 12KM does and it's got southern Minnesota getting slammed with heavy snow.
Check out these snow totals the NAM is throwing down, but know that the National Weather Service says this model is the outlier and isn't convinced it'll prove true.
Repeat: The National Weather Service is not sold yet on the map above being correct. They're thinking the other models are trending more appropriate, as evidenced in the American (GFS) model below, which shows some accumulations in southeast Minnesota.
You can see the differences in the NAM and GFS radar simulations (these might not show up in some browsers). First, the NAM:
As you can see, it's got a lot of blue, which equates to snow and thus the heavy snow totals it's projecting. Secondly, the GFS, which you can see has a lot more green, which equates to more rain than snow.
Regardless of what happens, it's going to be a wet and cold Saturday, and whatever snow falls will melt within a couple of days.
We shouldn't have to discuss temps 30 degrees below normal for this time of year, but it's the weather and it does whatever the hell it wants. We'll have more updates as the storm gets closer, and we'll cross our fingers that the NAM is wrong.