RCNYILWX

WSSI suggests that DVN upgrading some counties to a warning was a very aggressive move. Given that we had a warranted daytime warning event a week ago, it's questionable if the possibility of getting a narrow band of 6-7" of snow on a Saturday evening-early Sunday warning is sufficient to prompt a warning. Sticking with a WWA seems like it would've been fine. We'll see how it goes. Sent from my SM-S936U using Tapatalk

Call it 8.1" for me. Nearest CoCoRaHS (Naperville 2.5 ESE) had 8.5". Looks like about 8-9" was the range in this part of the southwest burbs. My largest (and favorite) November event since I've lived out here and largest overall for my area since Feb 1-3, 2022. The most recent big late November event in 2018 was slop in the southwest burbs until the very end. Sent from my SM-S936U using Tapatalk

I measured 7.3" by me, first time measuring all day though so there was definitely compaction. I don't have great places to measure since I have a big tree out front and also in back of my house. The Naperville 2.5 ESE CoCoRaHS is probably only a little over a mile from me so I'll see what they come up with in the morning. Sent from my SM-S936U using Tapatalk

Filled in nicely again, maybe another 1 to locally 2". Gonna measure later for a storm total. Has to be over 6" here too. Sent from my SM-S936U using Tapatalk

Legit SN to +SN out here in my part of Naperville (near DuPage Will border). Sent from my SM-S936U using Tapatalk

The top end range on the "official NWS forecast" graphic is the 75th percentile of the NBM distribution and the low end is the 25th percentile. Point and click is still quite high and possibly/likely overdone and our (LOT CWA) overnight forecaster did some work to rein it in a bit even. Looks like DVN made less adjustments to the initialized data so they have a large area of 12"+. I can say, speaking for my office, that we all strongly dislike the probabilistic winter page but unfortunately we don't have control over what's displayed on it.

I'm off through the weekend so will get to experience this one from the weather enthusiast side. In all honestly, haven't looked at model data since my shift ended this morning lol. How are trends for Chicagoland? Sent from my SM-S936U using Tapatalk

The last two EPS runs have been mighty impressive, which is usually the guidance suite you want on your side. Too far out to be super confident but if we don't see any sig backsliding, chances are pretty decent even at this lead time for the biggest synoptic event in this part of the subforum since the two weeks of winter in January 2024 (which isn't saying all that much given the lack of snow last winter). Sent from my SM-S936U using Tapatalk

I put together a long range pattern thoughts document for LOT staff a few days ago regarding the the impressive agreement in a cold and potentially active pattern with some staying power. It'll be primarily -EPO driven at first but then with the stratospheric warming/SPV stretching event ongoing, that tends to translate with blocking also developing in the AO and NAO domains. If we can keep the PNA neutral to negative, could set up for a rare snowy December for a good chunk of the region. For Chicago since 2010, the only Decembers that had both above normal snowfall and below normal temps are 2010, 2013, and 2016. Below normal temps but below normal snow occurred in 2017 and 2022. I know that Detroit had a very good December in 2017 from a much more favorable clipper track there. Sent from my SM-S936U using Tapatalk

Based on how much discussion there was on social media of the NWS snowfall maps with the huge ranges, was that a topic on here and did anyone attempt to address what those ranges represent? I'd be happy to, just don't want to rehash if it's already been covered. Sent from my SM-S936U using Tapatalk

Also if you're a Chicagoan who likes snow, getting in on any heavy LES prior to the halfway point of November is a big win and extremely rare (I don't recall any events in my time here). I believe there may have been one back in 2000.

This. As this case shows, it's tough to get things just right for a certain location with lake effect on the south end of the lake even when there is stationary banding. The jackpot zones are almost always going to be narrow. It's what makes events like Feb 14-16, 2021 rare for the city.

Just leaving a busy evening shift. TAF verified (edit: at MDW, need ORD still) [emoji123] Sent from my SM-S936U using Tapatalk

The potential is def there for a very favorable low topped supercell sig tor environment, particularly if the more aggressively moist HRRR/RAP depictions pan out. Glad SPC bumped up the tornado threat. Other than being a little surprised Bentley went right to the 10% hatched (vs. unhatched 10% or perhaps a smaller 5% tor) given questions on the specifics with the moisture and the resulting 0-3km CAPE, nice outlook and well written discussion. I'm liking near/south of the IL and Kankakee River in LOT CWA, which gives more wiggle room south of the warm front given the ~40 kt SSW Bunkers right mover vector, and low hodographs have generally looked a little better with southward extent in the warm sector within the CWA. Might see about chasing (for the first time since 2016) since I won't be called into work after working 7 shifts in a row.

Timing currently looks unfavorably late locally (LOT/Chicago metro) on Friday regarding any substantial severe threat. Since these deep negatively tilted troughs/closed ULLs often trend slower, the system slowing more into Sat may be the best path to getting some severe into the CWA. Sent from my Pixel 9 Pro using Tapatalk

And now, they froze our GSA credit cards. I will say, the commitment to the bit of hurting fellow Americans at all costs by any means is quite something. The level of brainwashedness to be able to hate a group of actually hard working people in the federal govt that don't apply politics to the jobs we do has to be unprecedented in modern history. Edit: Sorry, not frozen, a $1 limit [emoji51]

Thank you for the words of support. It's comforting to know that there's a lot of people who are angered about this nightmare and have our backs. I agree that there's outright fear among non hardcore MAGAs in the GOP. I think that's a big driver in the rubber stamping of unqualified nominees to Cabinet positions and the silence on the monstrosity of DOGE. But they're gonna be getting more and more anger from constituents considering the high approval ratings of NOAA/NWS and other agencies. Ultimately, all we need is a few to be unexpectedly brave given the small margins, and it gives me a small sliver of hope. That said, you're absolutely right the people in this administration could care less - they're carrying out the Project 2025 playbook that Trump laughably disavowed. So if we don't get a few GOP reps to flip, things will continue to get worse and even those of us in the agency for 10+ years are probably in jeopardy of being laid off.

Horrible day and the worst is still yet to come. For those of us in the thick of it, we need the support of everyone who appreciates what we do. Contact your Congressional representatives. The staffing shortages caused by the fork and now the probationary employee firings have us on defcon 2 level in terms of how bad it is. The goals of the people staffing this admin will get us to defcon one and beyond. I've been in the NWS since 2009 and I fear for my job at this point. They're demanding RIFs (reductions in force plans) by March 13th. This stuff technically is illegal and could be stopped by Congress if GOP Senators and Reps muster up the will to stand up to this for once. Not very optimistic about it, but maybe understanding that offices in their states or districts would have to close and services degraded, and the flood of complaints from constituents can make a difference. Sent from my Pixel 9 Pro using Tapatalk

Maybe someone more intricately involved in NWP can chime in, but my perception from my NWS career (started in Feb 09 at OKX) and my hobbyist phase going back years before that, is that modeling has grown less stable at closer in lead times on the most important details for system evolution. I think that global modeling systems are better than they've ever been at nailing the large scale pattern at long leads, but these large swings inside D5 feel more common to me than back in the 2000s and 2010s. My theory is that it's partially related to faster flow due to CC and partially related to ever increasing resolution (high resolution garbage in still = high resolution garbage out; ie. errors in those high res details, such as convective parameterizations, reach many of the members which all have the same physics and then amplify). I have no idea if I'm right on this, but I'm def interested in hearing from others better versed than me. Sent from my Pixel 9 Pro using Tapatalk

Heh, revisit my 2nd post about a 4-7"/5-8" type event for the Chicago metro going to 1-5" in 2 days. Sent from my Pixel 9 Pro using Tapatalk

We've definitely been on the cusp of something better but had too much predominantly dry NW flow in January after missing the big early January event not too far to our south. And then this past week looked good synoptically but again didn't come together for a widespread significant to major event (places in IA, NW IL, WI did do very well on Wednesday with mid-level frontogenensis and high ratios). Regarding the 98-99 winter, it's a good example of how getting a major storm or multiple to significant events (solid advisory to warning type amounts) makes a winter. This winter will end up much colder than that one, but getting almost 22" in one storm, an occurrence that's actually much more rare in our area than the northeast coast, went a huge way to ORD getting about 50" in 98-99. Even though this has been a weak La Niña winter, it reminds me somewhat of 2014-15, in that we had plenty of cold, dry NW flow (tied for coldest Feb on record that winter), but we cashed in with the Superbowl snowstorm in early Feb, with 19.3" at ORD the 5th largest snowstorm for Chicago. We're literally pennying up our snow totals out here this winter, haha. Makes it less fun to deal with the ~20 below wind chills we're getting tonight and tomorrow night. At least we do have about 5" otg in my neighborhood though, better than brutal cold with bare ground.

You're welcome! Honestly as someone who grew up in Queens with snowstorms my number one drive to getting into this field, I understand the frustration. We're somehow on track to end up with a solidly below normal temperature AND well below normal snowfall winter out here in the Chicago area lol. We just had a system back on Wednesday go from being in a winter storm watch two days out to a 1-5" event for most of the area. And then there was some potential for the current messy system hitting the northeast to become a solid storm out here and especially just east of here, and that missed as well (we did get a nice 2-4 hour burst of moderate to heavy snow Friday night). Sent from my Pixel 9 Pro using Tapatalk

While ensembles are the way to go days out from a threat, the important thing to keep in mind is that ensemble systems (some more/less than others) tend to be underdispersive, meaning that more members will in general come out in the general direction of the operational. When you look at members showing various scenarios, the probabilities are not absolute probabilities - they're called experimental probabilities. While it's fair to say that taking all systems and other op solutions into account allows you to lean a certain way in your thinking (such as there probably being a higher chance of the system missing much of the NYC with heavy snow as of this current lead time), at point X lead time, all member solutions are still equally plausible. When there's still guidance members showing the outcome snow lovers want, it's still a plausible solution and can't be ruled out yet. Definitely understand not being optimistic when the 84 hour NAM is the lifeline, (and I personally wouldn't be right now if I still lived in and forecasted for the NY area), but there really is plenty of time for changes. Past misses this winter aren't necessarily prologue, while it's 4+ days out. This post may end up meaning nothing, but I think it's some good context when tracking winter threats.

Heaviest snow here since the second mid January event last winter (the Friday morning 2-3"/hour thump followed by 40-50 mph wind gusts). Edit: Probably 1/4 mile or less visibility

From everything I looked at today, rates should be good for during the meat of the event, the main burst from the late morning through the afternoon. Felt confident enough to go with temporary 1/2 mile visibility in the 18z TAFs (in collab with the CWSU), which is not super common for us to do near or over 24 hours out. Forecast soundings are supportive of 1"/hour rates at times, so maybe the beefier looking sim ref output from some of the CAMs are onto something. We did account for the possibility of some lake enhancement of the totals into NE IL, though soundings don't look particularly impressive to generate notably higher totals (and impacts). Feeling pretty good overall about the 3-6" range for the metro mentioned in the advisory. Sent from my Pixel 9 Pro using Tapatalk