RCNYILWX

I think that, however much one wants to ascribe CC to things, the reality of the winter climate on the west side of the lake at this latitude (Chicago area and west) is one of volatility. These forums became really popular back in the late 2000s and early 2010s. 07-08 through 10-11 happened to be the best 4 year stretch for winter enthusiasts in this area since the late 1970s. Since that stretch, it's been much more mixed. The highs of the highs (13-14 and GHD II) and the lows of the lows (11-12 and 16-17) and a lot in between. Last year was extremely cold and active just west and north of here through Feb after a break in December-early January and we had a good stretch of winter from mid January through beginning of Feb. 17-18 had fairly lengthy doldrums but also had a memorable stretch of 9 straight days of measurable snow and the bitter cold of late December-early January. This really isn't unusual for our winter climo. Think back prior to the 4 year run, the 00s were not great until then. 00-01 had one great month, 01-02 was one of the worst winters until March 02 (which still sucks when you think about it), 02-03 was only good east and southeast of here and 03-04 was also not good here. 04-05 had one good month in January and 05-06 was torchy with only 26" at ORD. The 90s also were very mixed, with the best event of the decade being of course the 99 blizzard. The 80s were mixed for snow as well, 81-82 the big snow season of a decade otherwise known more for its extreme cold shots. So I understand why there's a lot of complaints about this winter, it hasn't been good for winter interests after the early start. If it doesn't turn around in the snow department, then it would rightfully deserve a low grade, but it wouldn't be unusual in the context of winter climatology. Stringing together good stretches and getting things to break our way with storm tracks or not is what separates the good from the mediocre winters and often one or two events separate good/mediocre from bad. It's the winters like 13-14 and the late 70s are the exception to the rule and are once a decade or every couple decades type phenomena. Having 4 consecutive good winters like 07-08 through 10-11 is also rare on the climo spectrum, but a lot of us are constantly hoping for a stretch like that.

00z EPS (ECMWF ensemble) has continued theme of last few days of going to a very cold pattern look out in the day 10-15. MJO is at a very high amplitude phase 4 crossing into 5, warm phases for the winter explaining the very pronounced east/southeast ridge currently. According to information posted on other subs by Don S, this progression has historically supported the MJO wave keeping enough amplitude to progress into the colder phases. Assuming this holds, the idea of a sustained colder pattern unfolding later in January and beyond holds merit. The GEFS has also basically gone over to the EPS idea out in the extended. I still think our best chance for a more significant spread the wealth type of event would be prior to the pattern going in the direction of the EPS, if it's on the right track. Thereafter, the exact position and orientation of mean western and Alaskan ridging and downstream trough over will determine whether we go to a very cold and dry clipper type pattern (ex. Feb 2015 after GHD II) or a more active but just as cold pattern (ex. January-February 2014). Sent from my SM-G965U using Tapatalk

Alek to Geos bullseye in IL. Lock it in. Sent from my SM-G965U using Tapatalk

The 00z EPS, in a big change in recent days, went to a broad west coast ridging and Alaska ridging out in day 10-15. PNA trended back to neutral on the teleconnection charts. So the hope there would be to not have an amplified western PNA ridge. If that sort of look verified as shown on the EPS it might be an active clipper/hybrid pattern versus the true dreaded CAD when the PNA ridging becomes more amplified and east based. Also that sort of pattern would be good for the lake effect belts. I've read some LR gurus wondering if EPS is rushing pattern change some, but it's done pretty well thus far this season. Edit: As posted above, that look would more likely favor the east coast for larger synoptic systems but still no signs of a -NAO. Sent from my SM-G965U using Tapatalk

The tight baroclinic zone over the region indicates potential for strong low and mid level f-gen and associated banding. Don't need a wrapped up system to get good precip amounts in cold sector with that as the mid December event along I-70 corridor showed, along with some of the events in recent winters (Feb 8-9 2018 comes to mind up here). Also, there's good agreement in strong upper jet divergence for large scale ascent. There's lots of ways this could go and it could certainly be a minimal event, but also counter reasons why it could work out. Sent from my SM-G965U using Tapatalk

Although it's not registering as a -EPO on the teleconnection charts because of the strong negative height anomalies along the Pac NW coast, the mid week ridge spike over Alaska due to a deep ULL over the Bering Sea functions as a temporary -EPO to dislodge that very cold air and send it southeastward. Then it looks like another ridge spike over Alaska Friday into Saturday that's trended stronger on the EPS vs yesterday.

That's actually incorrect. Look at the GEFS and EPS ensemble mean 2m temps over the northern Plains and northern Lakes next Friday and Saturday. There's pretty high confidence in a cold surface high being draped north of us based off MSLP anomalies in both ensembles.

Strong ensemble support for that long of a lead time. Both 00z EPS and GEFS ensemble means have a surface low tracking up the Ohio Valley and expansive high pressure off to the north/northwest. Next weekend could be a window for snow for some of us, along with an icing zone in between as you mentioned, in an otherwise fairly hostile pattern. Friday's cold front would temporarily shunt the low level baroclinic zone farther southeast and then the question is what comes of the southwest trough after it ejects. One way to avoid the phasing issues we've been having is to allow the southern stream wave to come up on its own and deepen due to the tight thermal gradient. Just to use the operational runs to illustrate the point, the 00z Euro kept the northern stream wave much farther north, allowing the southern stream wave to come farther north. On the other hand the 00z and 06z GFS brought northern wave much farther south, compressing flow between it and southern wave, which flattens heights and keeps the southern wave moving quicker and farther south. At the very least, some possibility of having more interesting weather to track. Sent from my SM-G965U using Tapatalk

Big news...Pivotal weather now has forecast soundings from the Euro. Sent from my SM-G965U using Tapatalk

Sign me up Sent from my SM-G965U using Tapatalk

Painful miss east Sent from my SM-G965U using Tapatalk

Written by my good friend and one of our lead forecasters at NWS Chicago. Have a happy and healthy 2020 everyone and here's to a fun year of weather. Sent from my SM-G965U using Tapatalk

Cross posting from January thread: Can say with reasonable confidence that January will be active. The big question is how persistently amplified the southeast ridging is and the placement of Aleutian/AK ridging. Getting the ridging farther east into the EPO domain could make for a more than serviceable month for central, western and northern portions of the sub. Farther south and east could certainly be dicey if this weekend and next week's possible window is not cashed in on. The January-February 2019 500 mb composite anomaly below and sensible weather results shows that the general idea being forecast by the longer ranges of the ensembles and Euro weeklies can work out really well for portions of the sub. On the other hand, a too amplified southeast ridge and Aleutian ridging too far west could make for a warm/rainy active month for much of the sub and congrats MSP and north/northwest. I don't think we can say yet for sure that the MJO being forecast to go with amplitude into the warm phases makes it a lock that it'll be a trash pattern even central and west, just that the warm risk is certainly there. If I'm recalling correctly, a good chunk of last January and February was spent in the warmer MJO phases. This shows it can work out for some of us, but did also make for the bad winter farther east and southeast in the sub and points east. Also, I'd much rather have an active month biased warm that at least gives a chance for things to break right for a good event than endless cold and dry. Experience shows us that for a big dog we need at least some southeast ridging. The oscillating going on in later ranges of the EPS shows that we'll be on the edge so we'll have to wait and see which way things are leaning. Finally, with the likelihood of stout low level cold air masses northwest of here and warm press from SE ridge, we'll also have to watch for sig icing events in the battleground zone, similar to last February. Sent from my SM-G965U using Tapatalk

Can say with reasonable confidence that January will be active. The big question is how persistently amplified the southeast ridging is and the placement of Aleutian/AK ridging. Getting the ridging farther east into the EPO domain could make for a more than serviceable month for central, western and northern portions of the sub. Farther south and east could certainly be dicey if this weekend and next week's possible window is not cashed in on. The January-February 2019 500 mb composite anomaly below and sensible weather results shows that the general idea being forecast by the longer ranges of the ensembles and Euro weeklies can work out really well for portions of the sub. On the other hand, a too amplified southeast ridge and Aleutian ridging too far west could make for a warm/rainy active month for much of the sub and congrats MSP and north/northwest. I don't think we can yet for sure that the MJO being forecast to go with amplitude into the warm phases makes it a lock that it'll be a trash pattern even central and west, just that the warm risk is certainly there. If I'm recalling correctly, a good chunk of last January and February was spent in the warmer MJO phases. This shows it can work out for some of us, but did also make for the bad winter farther east and southeast in the sub and points east. Also, I'd much rather have an active month biased warm that at least gives a chance for things to break right for a good event than endless cold and dry. Experience shows us that for a big dog we need at least some southeast ridging. The oscillating going on in later ranges of the EPS shows that we'll be on the edge so we'll have to wait and see which way things are leaning. Finally, with the likelihood of stout low level cold air masses northwest of here and warm press from SE ridge, we'll also have to watch for sig icing events in the battleground zone, similar to last February.

Any event like modeled on the 00z Euro has to be considered low probability this far out. But the good news is that it wasn't a one off. The 12z run yesterday had a system in a similar general area, just less phased and weaker. And there was modest 00z EPS member support for the time range. Can add next week to late Friday-Friday night possible rain to snow scenario for parts of the sub to *things to watch*. Of course the 12z operational GFS has no phasing at all with the northern and southern stream waves in that period.

Was gonna say, in a perfect world that's how we'd draw it up to keep the southeast ridge more muted, and plenty of cold air available in the source region. Even if we're on the edge at times, at least it's a more active look. Sent from my SM-G965U using Tapatalk

Cat. 4 Nor'easter Sent from my SM-G965U using Tapatalk

Big change on past couple runs of EPS in the long range. Recent prior runs had parked the PV near Alaska for longer, which is obviously not a good look for us. 12z run yesterday and 00z run last night breaks that down much quicker, with ridging returning sooner to near AK and an active/colder h5 look. With how much waffling has been going on in the long range on the ensembles, not ready to say the flip on latest EPS is for real. We'll have to see how tropical forcing (MJO etc) progresses, and plays a role in NH pattern evolution. Prior to those possible changes for the better taking place later during the first week of January, we'll have the brief cold shot behind this weekend's system followed by another warm-up due to the ++EPO from PV being over AK. Hoping@OHweather stops by with some pattern thoughts like on 33andRain. And Merry Christmas everyone. Here's to a much better January hopefully.

We didn't get lucky. The system looked promising for a band of heavy wet snow on most of the guidance and then things fell apart last minute. I issued a Winter Storm Watch for the Chicago metro and we got a FAB (flurries at best). Thankfully we made up for that debacle with GHD II. Sent from my SM-G965U using Tapatalk

I figure to be doing the same thing. So many east coast storms to relive. February 12 2006 was a great event, I actually was up in the Adirondacks skiing, and all we had up there was cirrus. Sent from my SM-G965U using Tapatalk

Weather.us has a sweet reanalysis page that they must have recently added. https://weather.us/reanalysis Sent from my SM-G965U using Tapatalk

The 12z Euro ensemble trended much colder into the first few days of 2020. Not sure if WxBell images are fair game, but here's the day 10-15 500 mb height anomaly prog.

The ensembles don't look half bad for the end of the month with both the EPS and GEFS in agreement on a -EPO/-PNA alignment. Obviously far enough out/subject to change and no guarantee of a spread the wealth snowy stretch, but reasons to be cautiously optimistic if we can get that look inside 10 days.

Looks mostly dry so if Monday works out we'd probably only gradually melt it and temper the warm-up. Sent from my SM-G965U using Tapatalk

I haven't noticed it to be a significant issue, maybe with a few events, would have to collect some verification data to know for sure. The Euro was even too wet locally with some of the early season snow systems this year. Sent from my SM-G965U using Tapatalk