Because of how cold it's been lately, we haven't had to think about any other type of precipitation other than snow for a while! With warmer air moving in now temperature profiles will be changing and that will bring the chance for more of a mix in parts of the Midwest Sunday.
Winter Weather Advisories have been posted south of the Quad Cities into most of Missouri and central Illinois. The latest from the National Weather Service in the Quad Cities:
From NWS Lincoln:
From NWS in St. Louis:
The storm will move in late Sunday morning and continue to move east through the night. Timing is pretty consistent, but there are some differences on how warm it gets in the mid levels of the atmosphere - and that will mean the difference between sleet or snow.
Here's the latest accumulations of the GFS showing the different types of precipitation expected:
Just ice accumulations on GFS:
Ice/freezing rain accumulations are general light - less than 0.10" with some snow possible where it's going to be colder. Here's the European:
Pretty similar with some higher amounts of freeing rain right near the Iowa/Missouri border. The WRF and NAM have been more bullish with warmer temperatures in the mid levels and leading to much higher ice amounts. I think a little too high:
I do think these ice amounts are way too high and there may be some isolated spots that receive up to 0.15" of ice accumulation. I also think both models are too far north and the chance for ice accumulation is going to primarily be south of I-80.
There is still uncertainty on the exact amounts but it is going to get slick out there, especially on untreated roads. Ice may also impact the Monday morning commute in southern Iowa, Missouri and Illinois.