The latest models are in and the stage is set for a high impact period of weather beginning with snow tonight and record cold by Tuesday. Winter storm warnings or advisories are out for most of the area along and north of I-80
The trend in most of the models, especially the latest U.S. based models has been for a slight southward shift on the heavier snow band. With the depth of the cold air currently in place I think that idea has merit. Here is what the NWS shows for snowfall in my area. I think the 5" line could extend further southwest running near and north of a line from Waterloo to Cedar Rapids and then towards Clinton. That's more in line with the recent 18Z runs which I will show below.
Now here's the 18z GFS
The 3k NAM 18Z
The NAM 18Z
The GEM (Canadian) 18Z
The EURO 12z (Currently the outlier further north and lighter.
The regional EURO
As you can see, there's good consistency on all the modeling except for the EURO. It will be interesting to see if the king once again rules the kingdom. I'm not so sure on this one. I'm leaning towards the NAM and 3k NAM right now.
The snow spreads into the area this evening from northwest to southeast. Most of the accumulating snow will be out by daybreak. In the south especially south of HWY 30 some sleet, freezing rain, or freezing drizzle is possible before that happens.
Then the winds turn to the NW and the onslaught of bitterly frigid Arctic air begins. All-time record cold is still on the table along with wind chills to 55 below. Tuesday through Friday will be an eye opening experience. This is deadly cold...can't emphasize that enough. Roll weather...TS