cyclone77

Yeah I'm actually starting to get sort of an uneasy feeling about this lol. Really hope the house can handle this in regards to pipes etc. Not very many people around here have engine block heaters like what they have up north, so there's going to be a lot of people with vehicle issues Wed-Thu. Another thing to point out is the longevity of these extremes. Usually if this area gets down to the mid -20s it's only for a few hours at most. This will be a whole other ball game.

The new 00z HRRR would have a new state record for IL early Wed. Has -37 at Galena at 11z. Widespread lower -30s along and north of I-80.

Very bold wording from DVN this afternoon, as you'd expect. Point for here is down to -29 for Thursday morning. Wednesday night...1035+ MB cold dense sfc ridge to slide in acrs the area from the northwest. Sfc winds to continue to decrease under 10 MPH or even 5 MPH into the overnight. When combined with clear skies, deep snow pack, and frigid start to the evening, many areas to be colder Wed night than Tue night/Wed morning by at least a few degrees. Although the secondary H85 MB pool of -28 to near -30C will dump down acrs the GRT LKS and northeast of the region closer to the upper level vortex center, still lingering cold enough values to attain the fcst lows locally of 30 below or colder north of I80, mid to upper 20s below along I80, and 15 to 20 below in the southern third. Would not be surprised if some cold drainage locations north of I80 reach 35 below ambient temps. Thus many record lows for Jan 31 in jeopardy of being broken soundly, including all time record lows for some climate sites. Just brutal "pioneer days" cold of dangerous values. Even with the sfc winds dropping below 10 MPH, still getting wind chills of 25 to over 45 below into early Thu morning and the Wind chiLL headlines will continue through 18 Thu.

With wind chills already dipping to -55 over northern IL.

Average snow depth now up to 17". Think this might be the deepest I've seen here. GHDI came close, but this has that beat. Especially considering the multiple layers, including two ice layers. They're hauling snow away in dump trucks right now in the center of town. First time for that. Guess they ran out of places to pile it up.

I haven't checked this many simulated satellite forecasts since the eclipse event back in 2017 lol.

Ahhh, remember that Euro run from 4-5 days ago? Didn't quite get to what that was forecasting lol.

Point's been lowered down to -28 for Thu morning. The all-time record at MLI is -28 from early feb '96.

Finished with 3.3" here. Temp rallied big time overnight and vaulted from around 10 at midnight to 32 around 7am. Never did go above freezing though, and back to 19 now.

FWIW the flake size stayed very small during the heaviest band when it moved through here.

A bit over 2" now, but the back edge of the main snow band is less than a half hour away. Looks like we'll end up at, or just shy of 3". Nice little event, but a bit too fleeting to be noteworthy for this particular area. Still will be enough to get our snow depth up over 16", so def no complaints from me lol.

The old all-time record at Congerville IL of -36 certainly seems breakable if we can get everything to align. Sure would be awesome for IL to put a -40 on the board. For ASOS/AWOS sites I think the best chance for that would be at either the Sterling or Rochelle site. If the ridge ends up a little further east than the way it looks now then Dekalb/Aurora would also have a good shot.

1.2" as of midnight.

The daytime temps on Wed are looking like they really could be something special. Euro and GFS both show temps still around -20 at midday for much of northern IL. Wish there was some sort of stat that tracked peak daytime temps for situations like this. Daily max won't tell the true story since the max temp over northern IL will likely be at midnight. I predicted a daytime high of -14 at ORD in the contest thread, but there's a shot it stays under -15. More importantly, there's a good shot the temp doesn't bump back above -20 until after the noon hour.

Haha. Looks pretty legit out there right now with the wind whipping and fairly low visibility. Quite the change from yesterday's snow glober. Later on as the back edge approaches the snow may get more convective and hopefully the flake size improves with that. Temps will be a bit warmer as well. The good news is even if we only get 2-3" it would be a fairly dense snow which won't compact. Similar to that wind-blown event we had with the Jan 18-19th event.

Still a ways away, but I'm gonna go with an all-time record low at MLI on Thursday of -33. Only concern for me is upstream clouds that can sometimes come in a little faster than expected. At this point all other ingredients are pretty nicely lined up for an extraordinary low temp event for the area. I have a feeling many of us will be looking back at this thread in the years to come.

So far the snow is fairly granulated from the wind which may keep ratios in check. Was thinking 13:1 earlier, but it may be more like 10:1. Should see some nice rippage though for the next few hours before the dry slot arrives. 3-5" still looks decent, but may be on the low end of that.

And we're off. Light snow has commenced. Temp still at 8 atm. Hard to believe we may kiss the freezing mark in about 9-10hrs.

Nice low-level baroclinic zone out west. Mid 50s in central NE to near 20 in the northeast corner of NE.

Yeah like 863mph lol. On a serious note the Euro continues to indicate max (or I guess min lol) potential may be Thu morning. Ridge axis moves in and calms winds over a very deep snow pack. WAA will already be taking place off the surface, but we've often seen a lag in the reflection down near the surface in a powerful arctic air mass in prior events. It actually got colder than the 00z, and now shows -35 to -39 from the QC northwestward through north-central IA. Simply amazing. If the timing of the ridge axis is correct it will just come down to if there's any clouds streaming in from the west with that incoming WAA.

Looks like the bitter wind chills have arrived early in Iowa. Knoxville currently has a wind chill of -54 courtesy of a biting 750kt north breeze.

Jonger's been around some, but ALEK is still lurking in the shadows.

Nice to see in the final 6-10hrs we're starting to narrow in on some sort of a consensus.

The top of the weather station tripod is 20" tall. Gives kind of an idea of how deep the snow pack is this morning. Estimating between 13-15".

Yeah it looks that way. Hopefully the HRRR/RAP can keep trending upwards, but it's certainly looking like the 0.5" for CR/QC will be way too much. Still a nice 3-5" event though, if we can get LSRs over 13:1, which I think is possible.