Scattered snow showers are possible later tomorrow, mainly in the south & then some will come in from the north in the evening courtesy of Lake Michigan.
Highs will run 31-35 with north-northeast winds 15-30 mph as skies become mostly cloudy to cloudy.
1" or less of snow is expected. The best potential of 1" is northern Jasper County from lake effect. Trace to 0.6" are mostly likely elsewhere.
Note how the heavier snowfall is just south of our area from the storm system.
All it would take is a slightly northward shift & we would see much more.
We will monitor for tweaks to this forecast.
Lows tomorrow night will run 16-22.
CIPS analog actually wants to shift the snow northward. This goes against every amount of model data, but it nailed the two systems that overproduced earlier in the winter.
We will monitor.
If we can lay down enough snow, it will get very cold late Thursday night-Friday morning as strong surface high with calm winds & strong inversion sets up over the area.
Some freezing fog is possible.
Lows of single digits to teens are possible & I have toyed with lower numbers. I have toyed with thoughts that the coldest air of the winter may actually set up more for mid-February than end of the week, too. We will watch though. It sure looks like a lobe of the bitter cold over the deep northern Illinois snow pack to Iowa may move into the area, especially with some at least thin mantling of snow pack here.
That's a cold night sounding with stout inversion with strong surface high & clear skies with calm winds.
CIPS analog suggests pretty high probability that our numbers will drop below model guidance to single digits to low teens. Again, my own numbers show higher potential.
Storm system Saturday-Sunday continue to show a more southerly track. The very deep Iowa to Wisconsin snow pack with below 0 nights is likely a dominant culprit.
At first it looked to track from Iowa to southern Wisconsin with 45-53 here by Sunday. With this track, I went more for 37-45 & it appears that the precipitation may begin as some mix & snow before going to rain with strong southeasterly then southerly wind. It may then end as a change-over from rain to snow Sunday as temperatures fall to 30-33 in the afternoon after 37-45 early.
Winds will be strong from the north to 35 mph on the back side of the system.
Heavy snwofall of +4" may occur from Madison, Wisconsin to Chicago, Illinois to north of Columbus, Ohio. Even up toward Fort Wayne, 1-2.5" snow may occur at the onset of the system before changing to mix then rain.
If it tracks too far to the south then we will need to talk about more in the way of mix & snow here.
Monday may see a few flurries & snow showers early, followed by clouds/sun, breezy conditions & highs 31-36, 20-26 Monday night, then partly cloudy & 33-39 Tuesday.
It looks to warm up Wednesday to the 40s, then 50s & even 60 with rainfall & even some t'storms.
Locally-heavy rainfall is possible.
Another big surge of warm (the warmest) is possible around February 9-10 with rainfall & even some t'storms.
We will watch for severe risk as far north as our area with either system.
Near/record warmth is possible with this system.
Locally-heavy rainfall is possible.
Here is CIPS analog showing the high likelihood of the impressive warmth:
You can also see the potential of at least one significant, long-track tornado with this system when analyzing all analogs with CIPS:
A bit of a pattern change & layer of deep snow in Iowa & Wisconsin will force warming south of the area & sort of split the eastern U.S. into two pieces. It looks warm in the South & southern Plains to southwest U.S. & much colder in the Great Lakes, Northern Plains & New England. We will be in the colder side in the middle.
Mid-February looks colder than normal.
Again, this is a very mild winter, but it could tie or exceed the single digits cold night here in late January.
Mid-February also shows above normal precipitation with potential of an icing event & a snow event with that boundary between warm South & much colder north with the Iowa & Wisconsin blanket of snow.
Late February to early March looks warmer than normal with above normal precipitation.
Overall, the spring is wetter & warmer than normal until May with increased risk of severe weather, including tornadoes. It appears that dry line will be forced eastward by expanding Plains drought. When the dry line is forced eastward, we tend to get more in the way of severe weather in spring in La Nina years.
Focus for the summer is still on heat & drought.
The warmer than normal & drier than normal weather may last through September & October.
Only the active tropics would be the real factor to help mitigate this & the main tropical storm/hurricane track with heavy rainfall is the Florida Panhandle to New England. This is a frequent tropical track in well-established traditional La Nina patterns with hot upper ridging from the Midwest & Plains to southwest U.S.
There is still higher than normal potential of a derecho or two in the "Ring of Fire" in the intense heat & instability on the periphery of the dominant upper ridge.
At this point, winter 2021-22 is trending lackluster for snow & cold. If you are looking for a snowy winter, it may very well not occur until 2023-24 after increasing potential 2022-23 El Nino when viewed from an analog perspective. However, El Ninos can be snowy IF the temperature anomaly of the event is focused in the central Equatorial Pacific, rather than the eastern or western.