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If the liquid equivalent of 0.6" for that run is close, absolutely possible to get double digits. Averaging a 17:1 ratio would get it done at that liquid equivalent. The WxBell Kuchera algorithm has an average around 23:1 which is very likely still overdone for an average. However, in these events, within mesoscale banding if the thermal profile is favorable for a deep DGZ, and strong lift is well aligned with the DGZ you can get at least temporary >20:1 ratios.

They still look overdone, but in this air mass have a chance to be closer to correct in spots. Unfortunately Pivotal Weather doesn't have the 06z run to make a direct comparison. It largely comes down to how deep the DGZ is, how strong the omega is, and how well aligned it is with the DGZ regarding ratios. Having the cold air mass certainly helps when the lift is strong and well aligned with the DGZ.

QPF total got messed up so trying again Sent from my SM-G965U using Tapatalk

I'll post shortly, will post the total QPF, Kuchera and 10:1 for reference. Edit: Here you go

Euro bumpin again. If the guidance trends are to be believed, our amounts aside from LES going to need to be adjusted upward and headlines are going to need to be adjusted northwest today.

NSSL WRF is almost 18" for downtown Chicago by 00z Tuesday and still ripping at the end of the run. Sent from my SM-G965U using Tapatalk

For those of us on the northwest fringe for the synoptic, the 18z Euro bumped northwest a bit. LE looks decent too. If wanted I can post the WeenieBell Kuchera. Can we get a last minute shuffle like Jan 4-5 2014?

Just posted below you, was gonna say since LES inherently is a bit more uncertain, if they're gonna do it, probably not a big deal to wait until tomorrow morning's issuance. Sent from my SM-G965U using Tapatalk

I think the wording in my office's AFD was enough to imply that a watch might be considered without directly saying it. 6"/12 hour criteria for a warning seems quite doable for the LES setup. Sent from my SM-G965U using Tapatalk

Close to +SN under this band. Deep winter out there. Sent from my SM-G965U using Tapatalk

2.3" at my house as of 45 mins ago. Definite fluff again which helps when shoveling. Sent from my SM-G965U using Tapatalk

Through my employment in the NWS, recently was notified we're eligible for the 2nd highest priority vaccine group status as essential workers/first responders. Having had covid already, I wasn't thinking I was going to make a huge priority of getting the vaccine as soon as possible. My thinking changed as studies have come out about the variants (especially South African) evading prior immunity. I'm younger (36) and healthy, so it's never been about particular fear for my own health (and while symptomatic, my case was pretty minor), but not wanting to be part of a chain of transmission that sickens my coworkers and possibly ends up in others getting very sick and/or dying. Also, my mother in law is 60 and had cancer and had her spleen removed years ago. So even though there aren't signs that the variants have spread much yet in the US, that could change over the next month or so, and I feel like there's more urgency to vaccinate, even for those of us who have had the virus. And on that note, unfortunately the vaccine situation in Will County IL (where WFO Chicago is) is frankly extremely frustrating. The health dept has had a few people staffing a phone line in which thousands of people per day are calling. A few of my coworkers managed to make appointments and get their first shots, and a few others have theirs scheduled, but now WillCo Health Dept is saying they overbooked appointments and it's uncertain when they can schedule appointments again. I firmly believe the Trump admin should have done more to help the states organize their vaccine distribution regimes, similar to testing, but states and counties absolutely bear some of the blame for not planning better. It was known for months that the vaccines were coming on line -- they should have had better systems built up even with federal support lacking. I find it hard to believe they couldn't have had call centers set up and contracted out to build websites for scheduling appointments. Now I'm hoping I can get an appointment soon with my primary care health group, fingers crossed.

Regarding lake enhancement tonight into Saturday morning for northwest Indiana, the Euro is farther west with the low level convergence axis than the other guidance, bringing solid enhancement as far west as GYY. It favors the Lake-Porter area and several miles either side for highest totals in the CWA through tomorrow evening. We currently have a WWA out for Porter County and if observational trends this evening support the Euro, we may have to extend the advisory into Lake IN. I think we may leave things as is for the afternoon issuance though.

The Crib has been bouncing around a lot. I think that one is taken farther underwater than the shore reading, which is taken at the Jardine water purification plant. Since the lake gets highly stratified is less windy period and it hasn't been all that windy during this cold stretch, that might help explain things. The surface layer would cool very quickly and ice over while the depth at which the temperatures are taken wouldn't have much time to cool in such a rapid ice up, as you would have kind of opposite of summer when surface is warmest and cooler layers below. The ice itself would insulate the layers below, which is what snowpack does to somewhat limit how deep frost can develop in the soil. Sent from my SM-G965U using Tapatalk

The ORD total from yesterday is probably off by 0.2 to 0.4 based off analysis of all nearby CoCoRaHS sites. Sent from my SM-G965U using Tapatalk

While trends have been unfavorable for the Chicago metro overall for the Monday into Tuesday period, not going to write off a better outcome here when this is still 84 hours out and beyond. It seems that the PV lobe location is going to be a big player and if that can slip east northeast a bit quicker, would imagine a more expansive precip shield to the northwest. It looks like even based off 12z operational runs we have a decent shot to get clipped with enough synoptic forcing to allow for good lake effect/enhancement (with already discussed favorable parameters) that could penetrate decently far west and southwest into the metro and support at least a couple inches if not more, especially lakeside. The GEMs have put their eggs into the Sunday night-Monday period, which the outer ranges of NAM supports, and the other guidance doesn't, so I'm not sure what to make of that yet.

I have to acknowledge I was too optimistic/aggressive on first real post I made to this thread. What we've seen is an adjustment to what probably was always a more realistic outcome in this setup, to have broadbrushed lighter totals and then a more focused corridor where mesoscale banding could enhance things. The 12z runs thus far show that nicely, 2-4" in that swath which should cut across roughly the I-80 to 88 corridors, and can't rule out 4-5" totals if the banding is stronger and more prolonged than expected given likelihood of >20:1 SLRs. Finally, Sunday night into Monday is trending up, especially on 12z RGEM, which has a broad 4-6" across the CWA. Sent from my SM-G965U using Tapatalk

Pivotal has a 20% off sale going [emoji2] The DGZ is extremely impressive on both the UKMET and ECMWF from their 12z runs. Sent from my SM-G965U using Tapatalk

Think the heavier bursts are enhancement of the LES due to aircraft seeding. Sent from my SM-G965U using Tapatalk

Best climo Sent from my SM-G965U using Tapatalk

I'm trying not to get overly caught in verbatim model run QPF/snow output. It comes down to what the general setup features with respect to large scale and mesoscale lift (fgen, lapse rate assist etc), some of which was covered in our long term AFD section. Sometimes all it takes is the rough idea on footprint of the QPF and banding locations to have higher confidence that you can get a swath of overperforming ratios and totals along the lines of what happened Monday. What Friday PM-Saturday has going for it if the setup doesn't change too much is duration. So if similar ingredients come into play like what we had on Monday you could expect higher upside for totals regardless of the raw model outputs based off duration alone. I think part of the possible frustration with the weekend period is that we had several runs of the GFS with decent ensemble support offering up more widespread bigger event potential, while several posts were made outlining why that outcome was rather unlikely. Euro has had similar depiction on evolution for multiple model cycles in a row now, while varying in QPF/snow output and NAM at this point showing an idea on what totals could be like (in I think a narrower swath than shown) if it all works out.

It's way too early to be in the concerned phase but just as a matter of that run, the 12z GFS brings back nightmares of 2/24/16. Key takeaway is that it still has a nice storm and would be a good sign if the GEFS members have several good hits. From a sub-forum perspective, looks like a pretty high chance at this range for a widespread warning type event for portions of the sub.

We emailed the regional climate focal point who is in touch with the climate program developers, hopefully there's a fix soon. Sent from my SM-G965U using Tapatalk

For some reason, the new climate program added totals from 1/31 to the February F6 form. The amount is correct in table above but the listing below is where the program is erroneously adding in 1/31 amounts. Sent from my SM-G965U using Tapatalk

It had backed off from 12z run a bit. The mean was still respectable for 24 hour totals of 1-2+" at 10:1, implying a mean of 0.1 to 0.2" LE. Would expect if things pan out that ratios would be above to well above climo again. Sent from my SM-G965U using Tapatalk