Hoosier

Just wanted to point out that darker red swath in Iowa is 50 mm qpf, or 2"

Mixing to I-80 in the LOT cwa at the end of the RAP run. Not necessarily a very useful model that far out though.

It all seems to be coming together out there. May be flirting with an all-timer where the max band occurs.

Not sure I understand the wording of your question, and not sure which GHD storm you are referencing, but the GHD 2011 surface low bottomed out under 1000 mb as it appears this one will do. Big difference is that GHD had a 1050+ mb surface high that only gradually weakened, leading to a very impressive pressure gradient. GHD 2015 was also under 1000 mb, but had a weaker surface high.

I was just looking at that and making a gif as you posted. It is definitely out of the ordinary to not see the low level flow back northwest/west more quickly after the storm departs, but this has been shown on guidance for a while and continues to be shown as the surface high does not come southward into the Midwest quickly. Wouldn't be surprised to see spits of snow on the western shores of Lake Michigan at least into Wednesday.

Even though it is FRAM, which is better than looking at the basic freezing rain qpf, I do think it represents the top end scenario. I still think there could be a band of around/over a quarter inch of ice somewhere, but temps are on the marginal side and profiles aloft don't favor a particularly wide band. If somebody does get a quarter inch, it may be like 10-20 miles wide.

February 2018

I think the takeaway for me is that once again, it appears we are going to fail to put the best band in the I-80 corridor of eastern LOT/northwest Indiana. Probably been a few years now (Feb 2018?) since that corridor jackpotted in a significant snowstorm in the LOT cwa. But at least it appears that several inches is likely to occur.

Can someone post a FRAM freezing rain map of the 18z NAM. Thanks.

First call would be 7-10" for most of Chicagoland. Except 2-3" measured at ORD... just kidding. I feel like this is sort of on the low to middle end of the possibilities and giving enough respect to the shearing/weakening trend with time. Certainly possible it could hold on longer and lead to widespread amounts over 10" in a swath all the way through LOT. But for now, I would put the 12-18" band in places like southern Iowa and extending over the Mississippi River into some of DVN's Illinois counties. Will be curious to see if somebody can come in with 20".

Last 3 runs of the NAM ending at 12z Tuesday. Context matters.

The trend on the NAM is more important than the verbatim output right now, and it is gradually heading toward what other guidance has been showing.

I'd say it's bordering on that. Current guidance is in good agreement on 6"+ in northern LOT, so unless there's a southern shift, you're good. I know one thing, I'd rather be north of where I am for this one.

Bit of a facepalm run here. There's decent snow with the hangback feature on Tuesday but that is mostly just north of here.

Believe it or not, I have gone even longer without a 6" snow, and I'm farther north for those who don't know. Hopefully Kokomo gets a big storm sometime soon.

Larry King died, looks like it was from covid.

If I had to get in LOT's head, I think they may shy away from blizzard talk at this point because of uncertainty on there being heavy amounts eastward through the cwa (even though this isn't technically a criteria, but you need heavy enough rates for long enough) and lower ratios reducing the ability to blow around. Maybe I'm wrong though. Let's see a discussion with the B word Ricky!

No 15z RAP?

A healthy band of ice too (obviously the verbatim amounts would be overdone in some areas with precip rates getting too high)

I think the Canadian has been picking up on sleet too. That sound you hear is my board brother throwing something at his screen upon looking at the 00z Euro sleet output.

Snapshot but you get the idea. Nice co-location of heavier precip rates and 925 mb winds of 40-45 kts. Probably not that great of a mixing regime, but 925 mb isn't terribly far aloft and even shallow mixing would likely be able to 35 to maybe 40 mph gusts to the surface.

I would love to read RC's thoughts on the GFS boundary layer warming in the LOT cwa with a weakening surface low taking that track.

It was insane. If you didn't know any better, you would've thought you were looking at a lake effect snow map.

Gotta say I don't remember many big snowstorms that hit you hard and screwed me. Talking downtown Chicago area and not well west like ORD. If I end up getting screwed on precip type, chances are it will find a way to screw you too. You never know though. I had not remembered seeing a synoptic storm like 2/24/2016 with that hellacious gradient between my location and the city, and it happened.

imo, even a tenth could start to cause issues if it's coupled with gusts ~35 mph, let alone anything more.