psuhoffman

You are trying to learn. Don’t apologize that’s awesome! It’s much preferred to those that know nothing, make no effort to learn anything, and fill up the threads with nonsense year after year. Ive been getting the same kind of questions both in the threads and in PMs lately so later today (probably this evening) I’m going to revive the old winter weather classroom thread we had with explanations of various pattern drivers and analogs to past storms from various patterns with explanations of what made them work. I’ve been working on a project for a while looking at past mid atl snows and categorizing them by pattern type. I intent to finish today and post those results also. Something to do during the down time.

Have fun.

EPS is less enthusiastic but it did take a baby step away from the ledge imo. Slightly better ridging into AK. Some hints at improvement on the Atlantic side.

First let me clarify the point I was making based on history 1. If we get a strong central pac ridge the first half of Jan, that is highly likely to persist most of winter. 2. That pattern can only work if we get blocking 3. If signs of blocking don’t show up by mid January it’s highly unlikely things improve. History suggests years where blocking helped it showed up by mid January. So while im not punting anything now, if we get to say January 10th and we’ve been in a persistent central pac ridge +AO/NAO regime and guidance shows no light at the end of the tunnel then at that point yes I would say shut out the lights wrt realistic hope this season ends well. Still could get a fluke storm but chances of hitting climo would be extremely slim. What is my confidence that is what happens... 2/5 maybe. My gut still says this shouldn’t be a dumpster fire year. Historically enso neutral years with our qbo and north pac sst profile have been decent to good. There were some hints of a way out of that fate on guidance today. On the other hand climate changes may have rendered the analogs useless. Enso neutral years have been skewing less snowy lately. And I can’t ignore the evidence right in front of me wrt the pac pattern and the long term lack of blocking. I won’t pretend I’m not a lot less optimistic now than 2 weeks ago. So I guess right now I’m just waiting to see what the next 2 weeks shows this winter to be with an open mind. But unlike years when I argued we could easily pull a late save, history suggests the pattern guidance has been showing lately is not the kind of thing we recover from if that sets in for any appreciable amount of time.

That’s literally our only realistic way to salvage the pac look this year.

Why can’t there be analysis without some people exaggerating it to extremes. Good or bad. When someone says the pattern looks good suddenly they promised a blizzard. When someone says it looks bad suddenly they cancelled winter. Nobody punted January today. I’m glad HM is optimistic. But he also thought it would snow around the holidays. He did nail the -AO period but he missed the pac muting it’s impact. He also missed the AO then going positive again before the pac relaxed. No one is perfect. I say that because the only thing people said, including myself, was that if (somehow everyone misses the if) we get a prolonged central pac ridge with +AO/NAO pattern that’s a really bad sign for winter. And guess what it is. Doesn’t mean we will. Long range guidance is wrong a lot. But if 15 days from now we’re dealing with that look, HM is probably wrong and this winter is toast. But im not against him. I want it to snow. I hope he is right! But seeing a huge central pac ridge and +AO develop as we head into January isnt a good thing. Anyone who thinks that’s no big deal is kidding themselves. But we still have a long way to go before it’s time to give up.

Sorry I’ll check

@Bob Chill it’s a convoluted way to do it but the gefs manages a good look by building just enough ridging in eastern Canada to act as a bootleg block. The other key is this run backed off on the pac ridge just enough to allow the pv to pull back and allow that ridging. The changes were subtle but all in the right way to bootleg our way out of the disaster scenario. Fantasy land though. But I suppose looks like that show there is a way to avoid the doomsday look I posted earlier today! ETA: you ninja’d me

It’s over Greenland. I have used TT, USModels, wxbell at various times.

Well 12 hours away was a break for me. I said my peace on the pattern. I won’t continie the beat that drum. But I will point out anything encouraging I might see. The pattern shown on guidance the last few days is the absolute worst. It’s the stuff our dreg winters are made of. But we’re not toast yet. A one week aberration isn’t a big deal. But if that locks in for 2+ Weeks...that’s uh oh. There are ways out with that pac but they involve some AO or NAO help. Today showed a slight improvement. There were some baby steps. We need more but today was the first time I saw anything positive in a while.

There are some hints in the long range the PV might retreat across the pole. That’s far from ideal and would limit cold potential BUT it would allow ridging across Canada and I would take that wrt snowfall mid winter than the pac ridge raging +AO combo.

I was thinking “if that warm water really is driving that what happens when it finally freezes over”. Well....

@Bob Chill There are some signs the NAO could be starting to flip again out towards day 15. Way too far out to buy anything but it’s hope at least.

@WEATHER53 and im not crapping on old school methodology. A sound understanding of the basics is a good foundation. But there is a reason we progressed. It’s amaxing what old timers were able to do but truth is accuracy sucked before NWP. There were huge busts at very short leads regularly. And forget even trying to nail a pattern from 2-3 weeks out. They had a hard enough time with 2-3 days. Now I’m not blasting them. They were severely limited in what they could do. Sorry but the human brain can’t possibbly handle all the variables that influence the atmosphere at long leads. So I’m not even sure what you are advocating! That we go back to pre NWP methodology when there was often no advance warning for major weather events?

Your timing is lol. The EPS has been killing the pattern at range for a while now. Absolutely nailed the current pattern from weeks out. Frankly the climate models nailed the look from months out. And wrt discreet synoptic features they have been good inside 72 hours when they should be. We’ve had no major surprises or model busts. But don’t mind me, just continue chasing windmills.

Good catch. We’re going to need some help on that side so that’s definitely something to watch. Tbh seeing the Atlantic side collapse really bothered me more than when we saw the pac turn a couple weeks ago. Once we got into December and the pac pattern started to show hints the analogs I was looking at suggested if we had a good winter it would be Atlantic not pacific driven. My vision (and it matches enough of the pattern analogs a week ago) was as the season progressed the Atlantic would assert more influence and block up the flow enough to cause a split jet and allow the pac trough to cut under. But I was aware there were also some comp years where the NAO broke down and those went on to be not so good. So seeing the breakdown of the AO/NAO regime was more troublesome as it made those years clearly more similar. I think if were going to make this work it’s going to have to come from some help up top or a lot of luck with a transient Atlantic feature.

The problems in 97 were an atrocious AO/NAO. The Pac wasn’t perfect but it wasn’t the main problem.

@Bob Chill yep. A fluke flawed pattern event can pop up anytime. Even the worst years it usually found a way to snow by accident once or twice. I will still track. I will still hope for the fluke. And if things improve wrt to the NAO soon perhaps not all is lost. But I’m not a stick my head in the sand sugarcoat it kind of person. Better to pull the bandaid off quick imo.

No a majority of the snow that year was the first half including a big storm around Xmas.

@C.A.P.E. @Bob Chill @frd @WxUSAF We are all seeing the same discouraging thing and hoping it’s temporary. I debated not even making this post (because att things look more like the not so good analogs I’m about to discuss) but the truth is the truth and if some can’t handle it oh well. But I will only say it once and then look for hopeful signs. (It’s not 100% doom and gloom) That said if we look at the analogs to the current pacific look, the evidence suggests that it will prevail most of the winter. When that anomalous of a central pac ridge shows up this time of year it tends to be a dominant player for the remainder of met winter. There are a set of analogs though that flipped colder and went in to at least a snowy period at some point later in winter. But they had something in common. NAO help. Even during the bad periods the NAO showed signs of being favorable. Later in winter the NAO was able to offset the central pac ridge by forcing the western trough to cut under the NAO ridging. This is the h5 look to the years with a similar pac look that went on to a decent snowy periods. unfortunately the modeled pattern coming looks much closer to the years that went on to be total turds. The difference is the NAO. If we don’t get any Atlantic side help history suggests we’re toast with the current look in the pac. And unfortunately history suggests that look is likely to persist much of winter. I tried to find examples of years with that ridge strength and alignment this time of year where the pac flipped...and it’s just not numerically likely. Now the only silver lining is there were examples where the NAO looked bad temporarily then recovered but if the +AO/NAO locks in positive for more than 10 days or so in early January that eliminates all the decent analogs and pretty much throws us unto the dreg Years. Some of those years had some snow early before the pattern locked in and a couple had a fluke snow very late in March but they all were pretty much total crap through the core of winter. I don’t like to say it but simply according to the analogs numerically if we don’t start to see signs of the AO/NAO flipping back negative within the next week or two at most...we’re likely looking at a dud year wrt snowfall. Hopefully peoole know I don’t just give up on a season on a whim and in previous bad starts I held on because there were signs things could easily improve. And if we start to see either the pac or NAO improve in the next week everything I just said is out the window. But the numbers say if this current look locks in for any extended period in early January....well you get it.

That’s not unusual though. It’s why our good snow years are few and far between sometimes. Getting multiple indices to all line up the way we want is numerical unlikely. Plus we need them to line up in an anomalous way. If all indexes were neutral that’s still not great for us. So most years we muddle through with an imperfect pattern and DC/Balt hope to at some point fluke their way to 8-15” of snow with some nickel and dime events and maybe one decent storm mixed in. That’s a normal winter. Then every so often we get a year where they line up in our favor and we hit big or a year where they all line up against us and we get 2002/2012.

It’s not just the pacific. It’s everything. The EPO/PNA/AO/NAO are all in the opposite phase that we want. If you take the northern Hemisphere H5 and completely flip all the reds and blues it would be our perfect snow pattern. We are in the exact opposite of what we want in EVERY way.

Was this supposed to make sense?

@cbmclean I think you asked about JB once...so something he just did this evening is an example of why he is lower than dog excrement. He posted a blog write up where he cherry picks various nonsense to imply cold in the east. But it makes no sense if you actually know a damn thing. First he uses the CFS mjo. Except the CFS forecast for January is hot poo. He talks about mountain torque feedback issues on the EPS except the GEFS and GEPS have the same trough alignment. He completely ignores the ridge in the Central Pac. Then he brings up a point about the TNH that completely contradicts his cold arguments. I find it unlikely he is a complete imbecile so imo he is playing people. Comforting the weenies and figures he can spin out later and so long as he keeps telling them what they want to hear they will keep coming back

DCs average high is about 45 even in winter. 50 is only slightly above avg. A truly cold pattern is also anomalous.