RCNYILWX

Made it to the office safely, drive time actually wasn't too bad with less cars out but the roads were trash as you'd expect. Just before I got here, had to help push a car up a hill on the road near my office and a little bit farther along a pickup was towing a sedan out of a ditch. Was heavy snow the whole drive in. We're about to do our 06z measurement. When I left home was estimating about 4" in southeast Naperville. Glad the forecast is working out pretty well for most of the area. Sent from my SM-G965U using Tapatalk

Is that LE starting up by your or just a small meso band or both? Sent from my SM-G965U using Tapatalk

Once we get an idea on ratios and how much heavy snow is left will give a better idea of exactly where totals will end up. Interested in the evening update from my office. I think it's distinctly possible that we'll be able to pin down an area of enhanced totals. Would be happy for my forecast to bust low. Sent from my SM-G965U using Tapatalk

It seems possible the absolute heaviest returns may not quite make it but that's also partly a function of a different character of the snow underneath the highest reflectivity. Very large rimed flakes have higher reflectivity than typical dendrites. The stuff over the northeast half or third of the metro 25-30+ dBZ will be more than enough to stack.

Solid SN borderline + here with good wind, which bodes well for when the really heavy stuff lifts in. Had the kids out in it and they were loving it. Sent from my SM-G965U using Tapatalk

Since I'm a weenie at heart like everyone on here, waited to see the 12z Euro. Had a feeling models were too warm today. Without a southerly component at the surface and in a retreating dry air mass it's hard to warm much with overcast skies. I think highest I went in the CWA today was 36 degrees, maybe a few spots of 37 far southeast. Tried to do the best I could with hourly temp trends to account for evaporative and dynamic cooling at precip onset. Aside from the areas that'll have mixing issues for a bit, looks all systems go. Sent from my SM-G965U using Tapatalk

The RAP might not be terribly far off at 850 mb. My guess is it's probably holding onto >0C too long with north and eastward extent. Main issue though is the QPF, very clear dry outlier in the 00z-06z timeframe when our heaviest snow is forecast. We find that the RAP is best for trends up to 6 hours out, so it can certainly help with diagnosing the effects of the warm nose on p-type. Sent from my SM-G965U using Tapatalk

In this case it wasn't even to cheapest bidder, we had a team that was working on it for years I believe. They were ready to roll out, had a comment/suggestion period where they were supposed to incorporate feedback from within the NWS, and from every comment I saw on an extensive employees facebook group post and also talking to the radar focal point at my office, they took literally none of the suggestions. If they had just gotten someone from academia with good web design experience, may have a much better page done over a weekend lol. Sent from my SM-G965U using Tapatalk

We're not even supporting mobile.weather.gov anymore lol. It's silly that we can't have a free app, we're not competing with anyone and it wouldn't be hard to develop. Sent from my SM-G965U using Tapatalk

If you want a good pay site, I think weathertap is probably still a solid one. O/T but it's too bad the NWS radar page update was fumbled so badly. We really could've had a nice page if they had just tapped in design experts in the private sector or just asked COD or other good pages from academia to share code to roughly mirror the good stuff they have. Sent from my SM-G965U using Tapatalk

I had 8.8" or 8.9" in the grids so that's a good line. Sent from my SM-G965U using Tapatalk

I think your location should be okay (maybe NW McHenry an exception to that) and you'd also be in the trajectory for lake enhancement tomorrow. Regarding that part of the AFD, it's something we noted on some of the CAMs that the heaviest sim ref seems to hit a wall and those 35-40 dbz echoes don't get all the way north. With it so close I wouldn't want to bank on that actually happening but it's an item to watch. Highest likelihood of being in that snow minima is out by Rockford, so Winnebago, Boone and Ogle. Western portion of Ogle and Lee look to have mixing issues through 5pm to as late as 7pm. Sent from my SM-G965U using Tapatalk

As a special storm day deal, until I go to bed later this morning, if anyone has any LOT CWA specific snow forecast questions, feel free to ask away and I'll do my best to answer. The overnight forecast that I put together in collab with WPC and surrounding offices attempted to toe the line between playing it slightly conservative vs what potential higher end outcome could be and giving an idea of the areas where we think have the best chance to end up in the 8-9" range or even higher. Those are the areas in the 8-12" range on our snow map. Note that even though the snow map range is 8-12" I think the highest point amount I have anywhere is a bit over 9". Enjoy the tracking today and I'll be up to enjoy the ++SN this evening! Sent from my SM-G965U using Tapatalk

You should be higher than that now in the updated storm total. Your area looks good. Sent from my SM-G965U using Tapatalk

Accounting for the above described feature we're bringing mixing into our west and southwest 1/4 to 1/3, which will eat into snow totals some there. East of wherever mixing makes it looks all systems go. 00z EPS 6+ probs actually beefed up for the LOT CWA. Sent from my SM-G965U using Tapatalk

I'd gladly be wrong on my calls on this one. So much time for this one but the changes we've seen on the operational run are good ones to end up with a snow event a few days after northern stream dominant frontal passage. Sent from my SM-G965U using Tapatalk

Noteworthy uptick in the mean QPF. Have been looking at 00z soundings from TX and vicinity and the moisture quality is legit. Also on mid level w/v can see our burgeoning synoptic system has a deep layer feed from the Pacific from southwest of the Baja. So we're getting Pacific and Gulf moisture involved. Sent from my SM-G965U using Tapatalk

We all look at the RGEM/RDPS on here but I don't think I've ever seen it referenced in a WPC model preference discussion. Sent from my SM-G965U using Tapatalk

I'll get a chance to look much more in depth when I get to the office in a couple hours. Initial reaction is that the NAM always seems to be like a windshield wiper for our area. Until we see model support for that depiction, I don't see putting a ton of stock in it at this time since as @Chicago Storm noted the PWATs were actually up on this run. WPC likes to lean on the ensemble means for QPF forecasting since those are usually more stable and they add in details from some of the high res stuff. Interested in seeing their thoughts when I get in. Sent from my SM-G965U using Tapatalk

I'll take what the 18z GFS runs are selling. Pass on snowpack nuking and hydro issues. Lots of time to go. Sent from my SM-G965U using Tapatalk

I'm back tonight with MTF so we'll both be diving into stuff. Can't say much about the slight drop in forecast totals since I recently woke up lol. I'll defer to those who have been closely following the data all day for now and probably chime in later when I've looked at more stuff. Sent from my SM-G965U using Tapatalk

It'll take some pretty wholesale changes to avoid rain in northern IL with this setup. I continue to hope that the operational ECMWF is too amped and to slow to swing the occluding cold front through. 00z Euro was slower than the ensemble mean and a good deal slower than the GFS's and the GEM. Sent from my SM-G965U using Tapatalk

This is one of the "under the hood" items I was mentioning, and I overlooked it last night. It's very easy to get caught up on model run QPF, but when you have this caliber of jet divergence, excellent moisture transport, top of the chart PWAT, and there's a disconnect with QPF, probably safe to side on the higher QPF guidance. With the pretty decent difference between the 12km and 3km NAM, I was wondering if the 12km's BMJ convective parameterization scheme could be messing with the output some and the 3km explicitly forecasting the embedded convective elements could do a better job in this case. Sent from my SM-G965U using Tapatalk

On that note, what are your thoughts on blowing/drifting potential? It's a good point about the actual air temperatures. The moisture content of the snow and overall density will be high but maybe it can still be blown around when temps are 28-30 instead of 31-33. Sent from my SM-G965U using Tapatalk

I didn't look closely specifically at your area, but for our far southern areas, without even looking at wet bulb, the 0C line just sneaking in there near southern Ford to me pointed toward evaporative and dynamic cooling doing a lot of work. The winds will be pulling from the departing high, so that'll help from an evaporative cooling sense and support for heavy precip maxes out dynamic cooling. Certainly uncomfortably close down there. Wish I could stay up to diagnose all the 12z guidance with everyone lol, but gotta get some sleep for another busy shift tonight. Sent from my SM-G965U using Tapatalk