Hoosier

Just call me the Spartman of Indiana

03z RAP

Overall trends are looking a bit better around here. Seems like things are favoring a somewhat delayed deepening of the surface low, with the GFS in particular backing off on the past few runs as shown below. Although surface temps may still be a problem, the prospects of more of the precip falling as snow are going up.

It sounds like the South Africa variant is better able to infect people who had the "original" covid.

Despite my pessimism, I can appreciate that we are even discussing the possibility of snow with a setup like this. There are plenty of times you aren't snowing immediately out ahead of a sfc low this deep.

Both 18z NAMs actually do flip it to snow here on Thursday afternoon. Even if that were to occur, there would still be the boundary layer temp issue to contend with, which would likely cut into accumulations.

Euro and UKMET have a system in the subforum (and likely to be a higher than average ratio snow). If you're going to flood us with maps all the time, what's 2 more?

Unfortunately Indiana has joined the 10k deaths club (confirmed + probable)

Ok, fair points. That being said, I think it would be foolish at this point to expect several inches out this setup where I am. Maybe there's a better shot of that in far northern IL. At least it looks like we'll break even or possibly gain some snowcover here before we move on to the weekend.

I'm having trouble buying that this would be a several inch snow here, like what the Canadian models are suggesting. It's not a bitterly cold antecedent airmass and that surface low is deepening pretty quickly and tracking overhead in a best case scenario or more likely northwest. Given the above, I don't know how we're going to escape boundary layer temp issues around here during the day on Thursday. The back side does look decent though for a burst of fairly intense conditions with the winds and snow.

It was definitely an oddball month for Chicago. It was only the 2nd time that January finished with a mean temp of 29F or warmer and also produced over 20" of snow January 1939: 24.7", 31.6F January 2021: 21.9", 29.2F Honorable mention: January 1967: 28.9", 28.8F

Departures The lows were more above average than the highs.

For the fraction of people who get infected with mild symptoms even after getting a vaccine, I wonder if the vaccine would reduce the risk of long hauler covid? The long hauler covid cases occur even in some people who had relatively mild symptoms during the acute phase of illness.

The Sunday 2/7 daytime temperature map brings back memories of 1/30/2019. I remember the GFS having lows in the -30s in Chicago, even at short lead times. Obviously ended up being overdone, though did have -30 readings in northwest/north central IL.

I wonder what percentage of 986 mb lows over Chicago lead to snow in Ohio.

I think as progged, this airmass would be able to get below zero at IND even without snowcover. It is hard to get way below zero without snowcover though (say colder than -10F), especially around 40N. We'll see though... maybe IND will have a snow pack.

Here's that part of the IND afd Several of the CIPS analogs for late weekend align with some notable dates. Of particular interest are favored analogs for 1/20/1985 and 1/18/1994...two dates/events responsible for some of the coldest temperatures in recorded history in our area. Those events though also had the aid of a deep snowpack and a cold airmass that had recycled repeatedly in the 7-10 days prior to those dates. Want to stress that we are not anticipating record cold as suggested above. But those dates being highlighted drive home the idea and increase the confidence that this is an anomalous level of cold that will be impacting the region by Sunday and Monday.

Still could change but this airmass looks pretty potent. I know some here aren't fans of extreme cold, but from my point of view, I wish we could've brought this in during January for maximum effect. Not that it can't get extremely cold in February (especially early in the month) but generally speaking the coldest records are in January.

The epic sleet storm in LAF was imminent 10 years ago. We did start off with a bit of snow or at least a snow/sleet mix iirc.

Interesting setup. Not everyday that you are able to snow right out ahead of a deepening sub 1000 mb surface low, and it's not like we'll be coming out of a partucularly cold airmass. Does raise concerns about the magnitude of boundary layer warming and how much snow could be junky in the "warm" sector. I guess we'll see.

Doubtful. At some point the daily rate of decrease in hospitalizations will slow down. Let's get it as low as possible though.

Shades of early January 2014 on that 18z run of the parallel GFS. There's the storm and then the polar vortex plunges in right after.

Added a couple inches since earlier this morning, putting my total at 10.8" with light snow continuing.

Just get to 10" at ORD.

Hey look, an anti-futility post about Chicago.