Hoosier

I think some of the models are having issues figuring out the saturation. Hence the odd looking strips/blotches of snow.

Cold air? How dare winter pull a stunt like that.

I'd go a tenth or two of ice accretion around here. The thermal profiles will be in a period of rapid transition and becoming more marginal, plus steadier rates at times won't accrete as well so have a hard time seeing more than that at least for now.

Using the 16 day op GFS as a counterargument Come on, man

Pretty robust low level jet and it has a significant orthogonal component to the isotherms. So basically, do not be surprised if the precip type transition zones get north quicker than the models.

Through 96

12z run was so bad that this is actually some improvement in southward extent of snow

Strange look... not that the amount has to be wrong but would expect something more uniform.

00z NAM was still fairly bullish on ice. Certainly some negative factors for getting really big ice amounts in this setup, like duration (maybe only about 3-6 hours tops in a given location) and surface WAA. But it could still get a little dicey, and it doesn't take much to start causing problems with trees/powerlines when you add some wind, and it should be at least a little breezy with a decent pressure gradient.

Fantastic post OHweather. Thanks.

The energy methods that you talk about are enlightening... sort of treating it as an integrated value like CAPE is. I have a question though. I have no idea where I got this from but a long time ago I read that in situations with a warm layer aloft, having -4C or colder in the cold layer greatly increases the chance for sleet, even if the warm layer aloft is pretty warm. How well do you think that works?

18z NAM is hitting the ice. But again, gotta take the freezing rain maps with a grain of salt especially when rates are higher.

If we can lay down a few inches with a period of sleet, there may be a chance to glacier it over pretty well especially if the low trends farther south to keep the warm-up a bit in check. That's what happened on 12/28/15... that sleet was followed by a lot of plain rain which really hardened it up instead of melting it all. I'm not as big on retaining snowpack as some here but it has gotten a little ridiculous. Would be nice to actually look like winter for more than a day.

Good spread on the SREF as you'd expect. There are some solid advisory snows in there for N IL though.

Serious though. No other model that I checked has something of that magnitude.

What is this weird looking tongue of dry air in between the 2 more moist ones?

Euro freezing rain map?

Hey, not gonna make the list. ORD is up to 4.8" since November 15.

Where'd this go?

Currently leaning toward 2-3" on the front end here. If it comes in under that, then this winter truly does suck. Even the above total would pretty much make it my biggest snow of the season... pretty sad.

The thing about front end thumps is that you better get as much precip as you can while the thermal profiles are cold enough for snow. Speaking of that, expect considerable virga for a while. Initial precip will get eaten alive with a dry layer like this.

This seems like a better setup than the last storm to get some ice into downtown, even if for a short time. The subfreezing air will already be in place (opposite of last time). Lake temps may be down a couple degrees compared to the day of the last storm though we'll have to see. Also the fetch over water will be a lot shorter than last time, and possibly becoming increasingly short with time as the flow turns more and more southeasterly. Another thing is that if the current timing holds, there would be practically no diurnal assistance in helping to get temps above freezing in northern IL... gonna have to be purely advective.

That is the storm I thought of after seeing his post and before reading yours lol. Generally speaking I think he's right though... the biggest ones typically are pointed ENE or NE.

18z GFS is noticeably slower.