Last weekend (Easter Sunday) temperatures were in the mid 80s. This weekend snow and near record cold will be in place to provide us a humbling dose of spring infidelity. In my 43 year television career I don't recall any part of my viewing area going under a winter storm warning so late in the spring... a new benchmark going forward. Take a look at the extent of the warnings from Minnesota and Iowa into Wisconsin and northern Illinois. Wow...not bad for April 27th!
Here's the low pressure center Saturday afternoon running along the Iowa Missouri border.
It's producing a wide range in temperatures at 1:00 pm.
Precipitation which starts as rain Saturday morning should quickly go over to snow near and north of HWY 20. This is the area (near and north of 20) that has the best chance of seeing heavy wet snow that could accumulate 4-8". I've seen several models showing convective snow and banding between Manchester and Rockford with more than 10". That is a possibility given the impressive forcing and QPF over an inch but it's far from a given. In fact, there are lots of mesoscale details that will go into generating snow and determining where and how much falls. We just won't know for sure until Saturday due to the delicate thermal structure of the storm.
Further south, closer to HWY 30 rain should eventually mix with or change to snow at some point in the afternoon. Accumulations are possible here too, especially if the transition happens sooner rather than later. Little if any snow is expected near and south of I-80. That said, here's what models are showing for Snowfall as of Friday night.
The 3k NAM
Total precipitation looks like this on the EURO
For my area the storm wraps up early Saturday evening. Skies will clear and strong winds will diminish by midnight. Temperatures could fall to near record levels by Sunday morning, especially where there is snow cover. The 3k NAM has lows in the teens where the ground is white.
Sunday, while not great, will see improving weather with highs back in the upper 40s to mid 50s (coldest where melting snow occurs). That is the latest I have for Friday night. Saturday will be interesting to watch. It would not shock me to see a few record late season snow totals. Why not, it's almost May! Roll weather....TS