Hoosier

Getting back to Wednesday... still some model differences in timing/magnitude, but a blend would bring in the coldest temps aloft right in the diurnal min, like 5-8 am. Hope it works out like that so we can squeeze every ounce of cold out of this.

I really feel that way. Wednesday morning has the better argument for being colder at ORD whether or not it's all-time record breaking. We may have a starting point that we've rarely or never seen before on Wednesday evening so wanted to respect that.

Still a bit out there, but we are getting close enough to be able to dive into some specifics. I'd say there could be a couple shots to approach the all-time record low at ORD. The first coming on Wednesday morning, which is more of an advective driven cold at that point with a bitter airmass aloft and winds staying fairly elevated. Then another one potentially coming on Thursday morning after having an extremely cold starting point Wednesday evening. Overall, Wednesday night/Thursday morning certainly looks like a better radiational cooling setup than Wednesday morning, though even then it appears the winds may not completely die off especially in/around the city. Also, the airmass aloft looks like it will be warming by late Wednesday into Thursday, so not having full decoupling could be a problem. I'm still not ready to predict an all-time record low for ORD, but to me, if it happens, the better chance of it occurring is on Wednesday morning because that is when the radiational cooling component is minimized, and anybody who pays attention knows that ORD can have problems with radiating. That being said, Thursday can't be ruled out due to what was mentioned above about the extremely cold starting point. Just my 2 cents and thoughts subject to change.

MEX has a high of -13 at ORD on Wednesday, which would break the all-time record low max of -11. Would just have to avoid getting midnight highed by a higher number.

The journey from near the north pole

Word to your motherlode. Here it comes.

Your area might be one of the suckier places to be coming up. Even with little/no snowcover, it's still going to get very cold with this kind of airmass and having the snowpack not far upstream compared to if it were, say, in Canada. Not much space for modification.

For Moline, the record is 4 days from 1/31/1996 through 2/3/1996. There have been 5 occurrences of 3 days and 4 occurrences of 2 days.

No doubt a serious, in some cases life threatening situation shaping up, particularly with bringing this kind of cold over big population centers. I'll say ahead of time that if anyone wants to have the morality debate about it, do it in the banter thread.

I think this even surpasses that Euro run from the other day that had -30s at 18z, as far as areal coverage. This is unthinkable... no way in hell, right? Beavis is probably going to print this out and hang it up.

12z Euro should be colder than 00z.

Meh, imo they don't count lol. I'm talking Rockford, Moline, Chicago... the big boys.

MEX mos has -20 at ORD on Wednesday. That is 35 degrees below average on a product that biases toward climo in the outer periods.

I really want to see one of the major climate sites in northern IL tag -30. Aurora has done it before but they radiate like crazy.

He is either extrapolating or has top secret access.

I'm not ready to go all Chicago Storm and predict the coldest temperature on record for Chicago , but I really like the odds of them getting into the -20s. That has only happened 15 times since records began. It also appears that there may be a shot at back to back lows of -25 or colder, which has never been observed before.

Thanks. Unfortunately that only goes back to 2002. I'd like to find something back into the 1970s/1980s.

Does anybody know where to find maps of snow depth for individual dates? I am trying to see what the snow depths were like across the region during the other notorious arctic outbreaks. That would be more convenient than looking up a bunch of cities.

The sampling thing has some validity but it can be overblown. You're not going to suddenly see a storm go from hitting Wisconsin/Michigan to hitting Kentucky, but changes can and do occur (and they are really significant if you are near a gradient!).

LOT already has -14 at ORD Thursday morning. A week away.

I have noticed that the HRRR tanks temps too much over snowpack sometimes.

I have trouble with wunderground these days so maybe somebody can check, but didn't the -27 at Chicago on 1/20/85 occur at like 9 am? So it doesn't necessarily have to be a nighttime min temp if you bring the coldest pool of air overhead during a different time of day.

For sure, and right now the clipper is looking good. Will be very interesting to watch this unfold. I consider coldest temp, hottest temp and biggest snowstorm for a given location as sort of the holy trinity of weather records.

I agree that the all-time record for Chicago could be in play IF these runs are generally right about the airmass aloft. I think it would have a better chance to happen in a setup like this, in which it's insanely cold aloft and more advective driven cold vs a warmer setup aloft that is heavily reliant on radiational cooling.

In almost 20 years of looking at weather models, I can honestly say that tonight's GFS is one of the craziest things I can remember seeing on a model prog for cold weather. And it's not way out there at 10 days plus.