RCNYILWX

Aside from the derecho, which I say thankfully wasn't bad at all where l live, definitely a more boring year weather wise. Noteworthy events in the LOT CWA in chronological order: January 10-11 significant lakeshore flooding. The winter side of that system was a big old bust, but the lakeshore flood certainly wasn't, as it was the most significant episode since Halloween 2014 and perhaps since the February 1987 event. - April 7th wind blown sig severe hail in far northern Illinois, some up to 3" in diameter, which is really impressive for an April event. The event was also noteworthy for the SPC handling it quite poorly in the outlooks (removal of general thunder in the day 2 update from some of the areas that had sig severe hail yikes), while it was a pretty synoptically evident good early season severe setup for days. - May 14th and 17th flooding events in the metro. The 17th was the most widespread flash flooding in the metro I think since the April 2013 flood and locally the most sig flooding I had seen where I live in Naperville. We issued our first (and warranted) considerable tag FFW on the 17th. The footage of the Chicago River flooding in the South Loop in particular was pretty nuts. - June 9th Cristobal remnants, more for the novelty of that setup. - June 26th severe event, with some sig severe wind reports. It was actually a pretty respectably widespread event by recent standards and it and April 7th are the most notable severe episodes of the year aside from August 10th. - June 27th flooding. A lot less fanfare than the May flooding because the rural southeast CWA was hardest hit, with actual observed rainfall of over 8" in southern Newton County and radar estimates up to 10". Had this rain occurred over the metro, we would've had a high end flash flood event. It was also my first issuance of a considerable tag FFW. - August 10th derecho and QLCS tornado outbreak, with the strongest tornado in the Chicago city limits since 1976. - Persistent summer warmth, including Chicago setting its warmest summer on record. It loses significance for me because we believe the ORD ASOS site has been affected by local construction to skew temps warmer there, including August being first summer month in our entire dataset in which ORD finished warmer than MDW. Summer 2012 stands out as much more noteworthy and memorable than summer 2020. - November 3-10 warm wave. Up there with mid to late February 2017 as the most impressive stretch of out of season warmth in recent history aside from Morch 2012.

IDK, I'm not trying to be overly optimistic, but I don't think the most recent Euro weeklies and GEFS extended (I don't really look at the CFS and it's probably getting discontinued anyway at some point) look terrible for January. It appears the EPO will average positive but it doesn't look to be due to a black hole over Alaska but northeastern Pacific and northwestern North America troughing that's pretty common in La Nina's. The -NAO signal is still there to mute heights some in the east. If there's enough dateline ridging (-WPO) and a huge vortex doesn't set up over AK, that typically provides good cold air discharge that can bleed from western and central Canada into the northern Plains and northern Lakes. I see there being opportunities and probably averaging near to above normal temps but potential for some decent cold shots assuming cold does build into the Plains. Don't get me wrong, it's not screaming great pattern or anything, but it looks more serviceable than the dumpster fire that has been December, except for a few lucky spots.

Those coarse resolution CFS maps don't make any sense. Even if you account for background climate signals, there's no mid and upper pattern configuration that would torch the entire continent. If Alaska is torching that extreme, then there's gonna be a trough over at least the eastern half of North America. If a good chunk of the CONUS is torching, Alaska will be cold due to ++EPO from the TPV parking nearby, like in 2011-12.

Need this post on the potential event thread. Sent from my SM-G965U using Tapatalk

Added more stronger SLP members farther south than 18z EPS so roughly 2 clusters within that increasingly large spread. The northern cluster is still favored slightly more, probably tied to the key question of the northern stream short-wave. Due to the difficulty of getting a proper phase like depicted on the 00z Euro and some of the EPS members, think it's a lower probability outcome but still worth tracking because it's all we got. Sent from my SM-G965U using Tapatalk

It remains a thread the needle setup. It's the old need a phase to work out sort of deal, which as we all know went great last winter. That said, the last two runs have had important changes toward increasing potential for a solid event. Most importantly, the northern stream wave is slower and not as strong, which allows the southern stream wave to come up and eventually phase in. 00z EPS is rolling out, so we'll see shortly how much ensemble member support the operational has. Sent from my SM-G965U using Tapatalk

Euro showing the setup we need for Wednesday night into Thursday to work out. Long way to go but nice to see it on this run. Sent from my SM-G965U using Tapatalk

The IT side of the agency is a running joke. We always talk about what we should have but don't. When we got AWIPS2 5 years ago or whatever it was, it was okay for 2010. Anyone seen the Sportsmax skit from SNL? 'I have 500 sworn affidavits that our IT is the best in the world!' lol Sent from my SM-G965U using Tapatalk

The NWS way. And they didn't even put correlation coefficient on there, only the most useful dual pol product. Can't wait until the next new page comes out in 15 years. Sent from my SM-G965U using Tapatalk

Just one run but the 00z GFS is interesting for December 23rd. Shades of January 29, 2008 with a sharp Arctic front and rain to 1-3" of snow, wind, and a flash freeze. Would sign up for that. Sent from my SM-G965U using Tapatalk

Chicago hasn't had a 6"+ calendar day snowfall since 2/9/18. The last 6"+ snowstorm was 11/26-27/18. Was thinking about that in context of how NYC didn't get as much as some of the earlier model progs, but Central Park still got 10.5", which was their largest December storm since Boxing Day 2010. The last double digit snowfall at ORD was 11/20-21/15 and the last double digit snowfall during met winter was GHD II. Obviously major events are a lot less common out here than the east coast but we're seriously overdue. December has become a feast or famine month locally, mostly famine since 2010, with only 2010, 2013, and 2016 featuring above normal snow. The prior decade on the other hand had some very big Decembers (with also a few lean years), none more so than 2000. We won't be able to finalize what the December normal will be for the '90-'20 climate normal period until this month ends but prelim data is the December average/normal will drop to 7.5" from 8.2".

How was 95-96 in SE MI? That's the only recent low snowfall Nina that was colder than normal here. Even though Nina's don't have the reputation of big east coast winters, 95-96 is snowiest all time for NYC and 10-11 was on track to threaten that had it not stopped snowing in February. The ensembles continue with a not terrible look to close out 2020. Not cold, but not a blowtorch, and near average heading into the coldest time of the winter isn't a bad thing for snow prospects. Sent from my SM-G965U using Tapatalk

It's not the big storm we all want, but the Euro showing a decent Pac hybrid clipper on the 22nd into the 23rd and then a follow up weaker wave into the morning of the 24th not far from here keeps some hope alive of getting snow cover down for Christmas. The ensembles also have a decent look toward the end of the run with a -EPO, -PNA, -NAO, -AO. May make for an active and not too mild stretch into January if that comes to fruition. Sent from my SM-G965U using Tapatalk

Not gonna pretend that I'm optimistic for next week. It looks as usual too progressive on the operational modeling in that timeframe. The trend on the EPS last 2 runs to become much more northern stream dominant, which was the more likely outcome anyway, really diminishes the chances for anything to work out for us out here. All I can say is that it's far enough out for changes to occur from the current look. The cold looks like it'll be legit not very modified Arctic air, so all we can do at this point is hope that somehow we can get some snow down for what looks like it could be a very cold Christmas period. CAD for Christmas would certainly be a nice cherry on top of 2020 lol.

Plot twist, Alek's backyard as the snow capital of the Chicago metro. Edit: In all seriousness though, the LES parameters aren't terrible tomorrow from a thermodynamics perspective and duration as well. When I looked yesterday, lake induced ELs were peaking on the forecast soundings at 6k-7k feet, which is a bit better than marginal. The problem is the possibility as partial ice loss as we lose saturation in a portion of the DGZ. Overall DGZ saturation won't be great and lift peaks below it, so flake size should be pixies. Hoping the FZDZ monster is avoided.

Thanks for posting those, never got around to it yesterday. 12z run today looks better than yesterday anyway. Sent from my SM-G965U using Tapatalk

Yep it's thread the needle but since literally the only threat in the extended, gonna stay interested. Also, a white Christmas would be a bonus with how depressing it is around here otherwise in December, especially this year. 12z EPS looks a bit better than previous 12z and 00z runs and starting to see an uptick in 24 probs of accumulating snow, owing to increased member support. The GEM and GFS in that timeframe show how we can easily get hosed if northern stream is dominant and too progressive. It's safer to bet that the pieces won't come together. On a positive closing note for the possible setup, the antecedent air mass will probably be bad like this weekend, but the incoming air mass looks to be legitimately cold. Sent from my SM-G965U using Tapatalk

Having experienced some of the greats in the east (1993 Superstorm, Blizzard of 1996, late February 2010 Snowicane to name a few) and GHD I, hands down GHD I was the most intense non mountain winter storm I've witnessed. Since living out here, I've missed the more recent east coast big dogs, but don't think any have surpassed GHD I for a widespread area in terms of wind and snow combo. The most comparable widespread intense wind/snow combo on the east coast to GHD I in recent history was in the same winter as that one, the December 26, 2010 "Boxing Day Snowstorm". Was legit paralyzing for the NYC area. Sent from my SM-G965U using Tapatalk

Euro ensemble still with a reasonably solid look around that time and even some individual member support. Risk there is the ridging out ahead, and any system favoring far north/northwest sub. However, the smoothed out ensemble mean isn't going to do a good job picking up the influence of the -NAO and its tendency to limit how far north/west systems can track. This is despite the ensemble mean showing a strong signal of a -NAO and the teleconnection chart from the 12z run backing that up. @Hoosier are we allowed to post images from WeatherBell on here? I could post some visuals to illustrate better if I can. Sent from my SM-G965U using Tapatalk

In grasping at straws mode, but just looked at the 12z EPS, and heading into Christmas Eve and Day it does have a pretty interesting look, with a frigid cold trough dumping into the Plains and ridging out ahead into the east though still with a -NAO signal. Surface pressure anomaly even hints at a surface trough over the southern Plains lifting into the lakes and an expansive high over the northern and central Plains. A few of the individual members as expected from the above hint at some potential in the region during that timeframe. 00z run wasn't too different so we'll see if any continuity develops in that timeframe. Also GEFS not crazy far off but not as potentially interesting as the EPS. While we could do a lot worse than that modeled pattern, need to get it within 10 days. The hope is that *if* a system does develop in that timeframe, the -NAO could help prevent warm cutter. Sent from my SM-G965U using Tapatalk

Also shows marginal temps overall. Surface 0 line is way up in northwest IL valid 12z Saturday. Gonna need heavy rates to consistently overcome the boundary layer issues. Sent from my SM-G965U using Tapatalk

In that setup, your backyard would be screwed until winds flip northwesterly Saturday evening. Lake is still quite mild. Sent from my SM-G965U using Tapatalk

Some initial thoughts on weekend system... When I posted a few days ago, wasn't too optimistic because of the bad antecedent air mass and rain prior to any snow. What happened in the past obviously doesn't determine what happens in a different event in the future. But, the fact that good rain to snow scenarios are rare suggests that lots of things need to work out at this latitude, so to be skeptical in this range. Give a nod to Euro for decent run to run consistency past couple days. But since it's the only model that's been showing this on the operational, want to see some multi-model support before getting more excited. While the EPS members trended better up until 06z run this morning, what I've noticed in the ensembles overall (including 12z GEFS) is that a majority the members with a solid hit favor areas north and northwest of here. The 12z UKMET looks like many of these ensemble members. It's gonna be a big time thread the needle to get a strong enough system to get good totals without it being biased farther northwest in the key synoptic features. Also wanted to note to use caution in getting too excited by the 10:1 and Kuchera maps from the Euro. As modeled on recent runs, temps don't fall solidly below freezing until the end of the event, along with good cold advection aloft (850 mb) not arriving til Sunday morning. These are all reasons to lean lower than 10:1 for ratios. I'd suggest looking at the snow depth output from WxBell or weathermodels.com as a good first guess and then can assess reasons why you'd get ratios to 10:1 or higher in spots.

First post a long time. Have nothing really optimistic to add to what's been written recently for the next few weeks. Barring no major changes for the weekend system (I'm not currently liking that period to work out), going to have to hope there's something snow wise in the cooler interlude behind that. Interestingly enough, both the GEFS and EPS have a -NAO look for most of their recent runs. Problem is they both develop a ++EPO toward the end of the run, which would torch the CONUS even in the presence of a -NAO. Would in all likelihood mean another warm Christmas period if that look pans out. Concur that January is probably best chance for a decent snow pattern for a time. For what they're worth, weeklies kind of point that way as well. In our local winter outlook (NWS LOT), we leaned warmer (actually got a nastygram from CPC for going against their temperature outlook 2 winters ago so we didn't explicitly say warmer than normal), and AN precip, which has strongest signal in Ninas. Since December is leaning dry, we should get most of our winter precip in J-F. Snow wise, think somehow we'll end up within range of normal. Last year was crappy as we all know and it eeked out just slightly below normal, though did have a head start from late Oct-Nov events. We're overdue for an area wide higher end warning event, so hoping we get 1 or 2 systems to track favorably. Figure if we do get into a more classic Niña pattern, we can manage to get one to work out ala 1999. Sent from my SM-G965U using Tapatalk

I can confirm that IND has a positive COVID case. IWX is providing service back-up through the weekend. So far so good here. Hopefully it stays that way. The way the agency is limiting our potential for exposure is by limiting people in the office to 2 people as much as possible, with main exception to that being severe weather. Everyone else is teleworking and we've developed remote capabilities so teleworkers can help the ops staff as needed. Last Saturday, we had someone doing mesoanalysis remotely. Edit: just got word it wasn't a positive case but someone who is a high risk of testing positive because of exposure to a positive COVID case. That forecaster is on quarantine and those who were in contact with the forecaster are self quarantining. They are planning to open back up tomorrow.