For three days now, the forecasted track of a Friday storm system has changed very little. What’s made this storm a little difficult to forecast has been the snow ratios we can expect when the precipitation arrives. This morning, we have a little more certainty on that front as well.
As a result, the National Weather Service in Des Moines has posted a Winter Storm Warning for counties along and north of Highway 30. This warning is for much of the day on Friday. You can see the counties affected in red in the graphic to the left.
Counties in northwest Iowa shaded in blue are under a Winter Weather Advisory and counties in green over eastern Iowa are currently under a Winter Storm Watch. I would expect that to be replaced with a warning later today with an advisory for counties further to the south.
The storm set to strike Friday does not have a lot of moisture to work with, but with such a cold atmosphere in place, snow ratios will be high, producing a significant, but fluffy snowfall.
In the graphic below you can see the forecasted snow projections at this time. Widespread 6”-7” amounts are possible over northern Iowa which is enough to warrant the Winter Storm Warning. One bit of good news with this storm is winds will not be exceptionally strong. That should limit the amount of blowing snow.
But there still is another problem. With the frigid temperatures, it will be tougher to treat area roads. We’ll continue to monitor this changing situation and bring you the very latest as it becomes available.