Light snow continues to move eastward in the viewing area. The heaviest is toward the end & is still over east-central Illinois.
So far, I have measured 0.4" at WLFI.
Totals by late Friday night should run around 1" for much of the area. A few spots may see more (to as much as 2").
Temperatures should peak around 21 Friday night, then drop to around 11 by early Saturday morning. They should rally for a late-day high of 19 as a new wave of light snow approaches.
The next several hours:
Wave of snow Saturday evening-night should drop near 1". The potential is there for a bit more if frontagenetical forcing can become focused over our area, rather than just south of us.
Just a few flurries are possible Sunday with lots of clouds & highs in the lower to middle 20s after teens in the morning.
Overall, blowing snow will not be a big factor this weekend. With winds 10-15 mph from the west & west-southwest to northwest, some blowing of the powdery dry snow will occur, but it doesn't look substantial.
Snow will approach Sunday night as temperatures begin to rise from the teens to 20 to 26-30 with strong south-southeast winds kicking in.
Snow Monday looks to transition to sleet & then freezing rain. It may go to all rain for part of the area for a bit, then go back to snow.
Snow may accumulate initially 1-2" in the north & 1" or less elsewhere. Icy mix & even rain should follow. Snow should fall at the end, as well with another 1-2" in the north & 1" or less elsewhere. Gusty southerly winds to 35 mph are likely.
A flash freeze is likely as temperatures drop from 33-38 to 10-15 quickly. Winds will turn to the northwest & may gust 35-45 mph as the Arctic air roars in. Any snow that falls toward the end will blow & drift everywhere. A band of +6" will occur with this system, but it appears it will set up just north & northeast of our area.
If this storm shifts a bit more to the south, we could very well end up in this heavier snowfall with less ice & rain. We still need to monitor this quickly. Even 50 miles would make a huge difference.
Frost quakes could occur Monday night.
Tuesday may have a few flurries & snow showers early, followed by temperatures falling through the single digits all day. Skies look partly to mostly cloudy. Winds look sustained at 20-25 with gusts to 40 mph.
We could be down to -5 to 3 by 6 p.m. over the viewing area & around -11 to -6 by 11 p.m. Winds looks just as strong then!
So, wind chills Tuesday will tend to run -25 to -15. By 11 p.m., some areas will see their wind chill drop to -35. Any snow will continue to blow around everywhere & drift about. In fields stripped of their snow cover, topsoil on fields lacking corn & soybean residue (underwent aggressive fall tillage) will begin to blow, staining the nearby drifts of snow brown, black & gray. This dust will blow off deeply-frozen ground.
It will be so cold that light, glittery snow should fall with pillars, halos & parhelias (sun dogs) & parhelic circles will be visible around the sun when it comes out behind the hazy stratus/stratocumulus clouds. A light glitter dusting is possible.
Frost quakes are possible.
We should be around -16 to -10 by Wednesday morning with west-northwest winds 20-40 mph. Temperatures may fall some during the day to -20 to -15 by late afternoon. Winds will be just as strong then! Skies look partly cloudy. It will be so cold that light glitter snowfall should fall off & on. Only a very light glitter dusting is expected. Sun pillars, halos, parhelias (sun dogs) & parhelic circles will appear around the sun when it comes out behind the hazy stratus/stratocumulus clouds.
Wind chills of -47 to -37 are likely.
Wind chills should completely bottom out Wednesday night. With lows of -25 to -17 & west-northwest winds of 10-20 mph, wind chills of -50 to -39 are on the table.
Frost quakes are possible.
The lowest atmospheric thicknesses (480-485 dam) since the extreme 1994 & 1985 cold outbreaks are expected, which means historically-cold actual air temperatures are expected. This means that the troposphere is going to shrink so much over the viewing area due to the density of the cold air.
The last time we had wind chills near this cold was January 2014 when wind chills reached -45. You really need to go back to January 1994 to find wind chills to -50 (based on the new wind chill scale). The Blizzard of 1978 saw wind chills drop lower than -50, however. Temperatures were around -20 with winds sustained at 30 mph & gusting 50-55 mph.
My thoughts are that our temperature will bottom out at that -25 to -17 level & stay there 12 a.m. to 6 a.m. Thursday.
By 7 a.m. Thursday, we should be around -21 to -14 with west wind at 8-15 mph. So wind chills will rise a bit to around -40 to -33.
It may be so cold Wednesday night to Thursday morning that glittery snow may fall from a cloudless sky with sun pillars, halos, parhelias & parhelic circles around the sun as the falling ice crystals refract light in vary ways. The last time I remember seeing snow fall from a cloudiness sky was back in 1985. As a 4-year old, the meteorology bug had already bitten me & I watch in utter fascination as glitter fell from a cloudless sky. It was in the morning hours as the sun was coming up in January 1985. We actually had frost like a freezer that formed on the west INSIDE walls of part of my sister's room & our laundry room! I also saw that in December 1989 & January 1994. I was too young to remember the January 1982 cold.
We should only reach -8 to 0 Thursday with sunny skies & a west-southwest wind at 8-13 mph. Wind chills will still run -26 to -15.
Thinking that the temperature will slowly rise Thursday night from -8 to 0 to 4-10 by Friday morning as clouds increase. Winds will run from the south-southeast at 5-10 mph. Wind chills should run -10 to -2.
It should cloud over with snow later in the day as a clipper moves in. Highs should skyrocket to 16-23 with southerly winds at 10-15 mph. However, wind chills should still run 2-11.
Minor snowfall accumulations are possible with this clipper into Friday night.
Some ice/snow is possible February 3-4 with 20s & 30s. However, I think a flash thaw with ice jams & 50s could occur around February 7. This sudden spring flash may only occur for 36 hours, but it will be an impressive temperatures rise with rain. Some creeks may completely back up with ice jams, causing significant flucuations in creek & stream levels & back flooding. We will need to watch all creeks for this. Huge chunks of ice may get clogged & back up at bridges on the Tippecanoe, Wabash, Iroquios & Kankakee Rivers.
It wouldn't surprise me if 0.60-1.15" of rainfall occurs in this sudden thaw with strong southerly winds 25-45 mph.
Much colder weather should follow with potential accumulating snowfall around February 9.
Bitterly cold air should return after that.