psuhoffman

These things still run in cycles... if the AO and PDO are both going through a decadal flip right now (they could be but its too soon to say for sure) maybe we are about to head into a heater. Of course keep expectations in check...heater periods are not necessarily what they once were, I don't think the 1800s or 1960s are walking through that door anytime soon, but we can probably pull off a run like 2003-2016 again. Snowfall is really fluky and we dont always end up with a big number around here even in a "real winter" 2004, 2005, 2007, 2009, 2011, 2013 were all "real winters" with periods of sustained cold and some snowfall around our area we just got unlucky and didn't score any flush hits those years. 2003, 2006, 2010, 2014, and 2015 we got the cold and the big snows. But it felt like legit winter "most" years during that stretch unlike recent years where we spend a majority of the "winter" in a fall jacket.

TLDR version: the day 15 looks very much like 2014 and 2015.

Transitioning to the long range again... the EPS shifted the trough axis east in the day 10-15 period. The AO/NOA is relaxing but looks neutral not hostile. The ridge does retrograde into the WPO domain, which as Chuck pointed out is not ideal, however I've noted guidance continues to indicate troughing in the central pacific underneath the WPO and EPO ridge. This creates a significantly different effect than when the ridge in the central pacific is full latitude being fed from the tropics. It's a much less hostile pacific look, more neutral in terms of its effects downstream on North America. It will force the ridging to creep into western N Amer. more which prevents a god awful -PNA digging for gold down the west coast, and also directs cold shots a little further east. Lastly, not only is this not a hostile look IMO, but its even a pretty good one if you have cold established across N America ahead of this pattern. In recent years when we did get a mediocre pattern it was often coming off a torch which just doesn't work...but going from a great pattern that establishes cold a mediocre longwave pattern is much more likely to produce snow.

EPS 50% snowfall, which btw is a much better indicator than the mean which can be skewed by outliers. It was an improvement over the previous run.

depends

P5 please

Not gonna happen we have to try to make it work. It can. We got a decent snow last year with a GLL. We got MECS storms in 1966 and 1987 with a similar setup so a bigger event isn’t even impossible. But I know it makes it a lot harder.

No it’s gonna be an issue

If the NS SW isn’t going to dig in behind we would have been better if it just wasn’t there at all.

Well the "valley" I am in there is at like 900 feet so the ridges aren't that dramatic, its more a plateau than true ridges with only about 300 feet difference between the peaks and valleys until you get off Parrs Ridge completely.

I meant in reality not on models at day 4

Odds are at this range there will be an error in where the baroclinic boundary sets up and the wave tracks, but in recent years its been equal chances whether that error is NW or SE. But a typical error NW puts us into good snow. A typical error SE leaves us smoking cirrus.

This is a different synoptic setup, the results yesterday do not have much to say about this next threat. That does not mean we don't get fringed again, but its a different set of circumstances.

Look at actual verification scores, we have improved significantly. Day 5 scores are similar to day 3 from 20 years ago! Peoples expectations just continue to increase faster than science in this area. But it wasn't all that long ago that forecasts only went to day 5 (remember TWC 5 day business planner) and day 5 was unicorn fantasy land. Now we look out to day 10 in the same way but expect better results.

Oh I definitely agree, but up here I will say often we pull off a win in an "ok" pattern more so than the lowlands in this sub, that's where we can get a win. There are plenty of examples where my snowiest week of the winter came during a blah pattern up here after disappointing results from a much better one.

Maybe, or like 2014 once the cold takes hold its difficult to scour out even once the h5 longwave pattern retrogrades. If you look at that year the pattern wasn't actually as good post Feb 15 but the damage was done and its difficult to scour out established cold that time of year unless the pattern becomes downright hostile which I am not sure it does...the trough pulls back but the NS is close enough and I don't see signs of a huge SER, but I know that's a traumatic thing to see even a slight SER lately! Analogs are also iffy for March, some years flipped back cold and we had another chance at snow late. But I know some toss March snow because it melts LOL

Agree with all this but recently we’ve seen waves that rely on baroclinicity out down impressive qpf, not just around here but I’ve seen that trend. I spend a lot of time up in Vermont and they’ve had a few crazy dumps up there in recent years where a progressive frontal wave dropped 20” without much dynamics or amplitude to the wave. Seems there is a higher bar than there used to be with these things. To be clear I’m not saying huge upside but it doesn’t seem to take much to squeeze out a decent snow of the wave takes the right track and there is a decent temp gradient.

Chuck, you're right a ridge there is not ideal, but if we couldn't get a snowstorm in that look we would almost NEVER get them in cold enso seasons or with a -EPO. We do sometimes get lucky with this exact kind of evolution, if we have a -AO and -NAO. It's not the ideal perfect HECS look no, but its about as good as we get in a cold enso season with a -PDO. It's still negative just not as much so. We do get snowstorms in a -PDO, its just harder.

the last storm didn't listen to me

But the pattern in the pacific you are referring too evolved the exact same way in 2006. The difference was the NS SW dove in behind the STJ wave and dug the trough better than most guidance is doing now that suggest the NS and STJ waves will be out of sync. The rest of the pattern is nearly identical. Especially the pacific which is specifically what you were talking about. Day of storm 2006 Day of Threat now

Here is an example of a close cold enso pattern match, the MECS from 2006 48 hours before 48 hours before our current threat The biggest problem here is the NS wave is not timed up with the STJ, its getting out ahead of it. If that was fixed this has the same potential.

you think they have shame?

Also this is kinda like having it both ways... the pattern is no good because it might be too warm and also it might be too cold and suppress. There is a HUGE range of permutations and possible results and only a very small minority falls into the box we need to get a big snowsotrm. In EVERY setup that is the least likely outcome so taking that stance would make you right just by default most of the time.

That composite is skewed by a LOT of nino storms...its not as far off if you only look at cold enso non nino snowstorms. The fact we are not in a nino lowers our chances of a major snowstorm significantly, but often when we do get the fluke cold enso snowstorm they do not match the larger composite. Also, there is a huge difference IMO between the -PDO regime we've been in recently and the coming look with a full ridge bridge from the NAO all the way into the north pacific, and a trough underneith it towards Hawaii. It's not nearly as hostile and those other factors around it matter just as much. It's not our BEST snowstorm look but we've had snows in worse looks than that. Its maybe a 7/10 look imo. I don't think the HECS is likely but I think we have a legit threat at something like the ICON or tonights GFS run spit out.