Hoosier

This looks like it may be the one for downtown and south (not that farther north can't do well too)

If Cedar Rapids/Iowa City don't rain, then given system orientation/track/evolution, it bodes well for areas downstream in LOT that have been snow starved. Sometimes you gotta ride the coattails.

When you go through the list of what can go wrong, one thing we don't have with this one is much in the way of convection down near the Gulf to rob northward moisture transport. So that is a plus.

LES struggling more than I thought it would at this time. Going to need a fairly quick ramp up to get to forecasted amounts in central/southern Cook.

It's gonna be alright.

Idk... all things considered, I'd say PIA is in a decent spot. As long as you don't set expectations at a foot.

Bit of an uptick in the lake effect band. Also shifting back west.

Seems like we've kind of narrowed down a track as it comes into the OV, give or take 50-100 miles. I'd actually feel fairly confident in saying this will be the biggest synoptic snow of the season here to date. Not necessarily because I am sold on huge amounts locally, but more because the bar is that low.

RC's lake effect disco. Went with SPS for now. Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 935 PM CST Tue Jan 26 2021 .UPDATE... 930 PM CST The main focus is on lake effect snow for parts of northeast Illinois and northwest Indiana on Wednesday. An SPS was just issued to alert of the potential for travel impacts due to rapid changes in conditions over short distances, including periods of poor visibility and snow and/or slush on some roads. Some of the 00z CAM guidance is rather concerning tomorrow morning, but given typically lower confidence in these scenarios on the west and far south side of the lake, opted for SPS issuance as opposed to Winter Weather Advisory. If it becomes apparent in analysis overnight that the lake effect snow will become single banded with moderate to heavy rates AND stall out for 2-3 hours+, then needing a WWA is a good bet. Just wasn`t confident enough to make that call this evening. A dual banded structure of light lake effect snw showers have drifted into Lake and eastern Porter Counties this evening. The appearance on radar is not too impressive and a look at soundings indicates that lift is on the weaker side, which should be the case through the night. This will change on Wednesday morning as a clipper-type mid-level short-wave will approach the region and induce some cold advection down the length of Lake Michigan, with 850 mb temps cooling down to -11 to -13C. given the unusually mild lake surface temps, this will bring 850 mb to lake delta Ts of up to 15C and lake induced CAPE of 100-150 j/kg. As a con to the setup that has been noted over the past few days, lake induced equilibrium levels (inversion heights) are not all that impressive, topping out at 5kft-6.5kft, depending on the model sounding you look at (which means DGZ will only be partially saturated). Also, while the delta Ts are more supportive than would typically be the case with that air mass over the lake in late January, still not extremely favorable. On the other hand, what we will likely have in place to possibly compensate for the somewhat negating factors of the setup is very good lake induced low level convergence and strong lower level omega (lift) due to the convective processes and large ascent from the short-wave trough. Have noted that in the past at times setups on the southwest to extreme southern tip of the lake can perform better than expected from more marginal ELs in the presence of very favorable convergence and low level lift. Adding to this concern from past events is the 00z CAM guidance, including the high-res WRFs (locally 6"+ on ARW!) and the HRRR (though HRRR has been mostly overdone with LES this season). All the above being said, the big question as always comes down to residence time of the band over given locations. Feel fairly confident that at least moderate to briefly heavy rates will accompany the activity, but lower confidence on the all importance residence time question. It appears the convergence will retrograde the activity from current location into portions of eastern Cook County and affecting downwind areas of eastern Will and possibly eastern DuPage and northeast Will as well. The lake effect band(s) would then eventually migrate back into Lake IN and then Porter later Wednesday PM. With the above concerns, hit the messaging harder in already issued SPS and plan to issue a graphic shortly highlighting these concerns. Will brief midnight shift on the potential and depending how trends emerge will dictate whether a WWA is needed in the early morning.

Can see the implied covergence zone on this obs plot

We've been posting about it here so might as well stay in this thread. And yeah, congrats South Chicago on those runs or in the case of the NSSL WRF, congrats downtown.

I know someone who is 20 and was able to get the vaccine. A healthy college student, not an essential worker or anything. I would hope that kind of thing is not happening too often.

http://www.eas.slu.edu/CIPS/ANALOG/analog.php

Imma Spartman the hell out of this thread if we see more runs like the para GFS.

ORD has skyrocketed to nearly 15" of snow this season.

Wow at the18z GFSv16. I-80 hammer time from northeast IL into OH.

Would you believe GHD 2015 is on the CIPS analog list again? A few other recognizable dates on there as well. #1 analog was March 9, 1999

Was alluded to earlier, but the GFS thermal fields look like utter nonsense. How it changes to rain up to I-80 with the surface-850 mb level lows tracking through downstate IL/IN is quite the feat. Not that it can't rain to I-80, but it's not gonna do it with that track.

You can see better consolidation into a banded feature on the recent scans vs the more disorganized/showery appearance earlier.

1-3 is safe bet/low end. I wish we had delta T closer to 20C for this... there would be major dumpage somewhere in Lake IN and perhaps Cook given the likely wobbly/slow moving nature in that corridor.

Will be curious to see what LOT does coming up. Do they pull the trigger on an advisory for lake snow or punt for the evening shift to look at. It seems pretty clear the band will become semi-stationary or wobble around the same corridor of Lake county IN and parts of Cook county later on. Quite likely to see advisory criteria amounts imo.

Can I politely request a lock in of the 18z HRRR?

It might be easier to get snow in Tallahassee than to jackpot downtown and I-80 in northeast IL/northwest IN these days. For the current storm, I was way more concerned about the heavier band ending up north even when some models had it here or south. For this storm, I am a bit more concerned about the heavier band ending up south of us but my view on that isn't as strong as it was for the current storm ending up north. But maybe it'll work out well for us... one of these has to.

Respectable enough

15.5" in Davey, Nebraska. So we had 12-16" in parts of NE and IA, but too bad it couldn't come farther east as looked possible several days ago.