psuhoffman

There is a lot loaded in this... First of all my post was not directed at you. Because I know where you and I disagree, and its simply about expectations and what we find acceptable. And that is ok. I don't begrudge you what you prefer. But that is not true of everyone. There were definitely some posts to the effect of "that pattern can be good". And we've heard that numerous times over the last 7 years and it just isn't true. Now I guess we could argue over what "good" is but my bar is an above avg snowfall season. If your definition of good is lower that is fine but we are arguing apples and oranges then. But I did not use 40" I used 25". And I only cut it off there because I was limited to 20 seasons. I could lower it to 20" and it wouldn't change the pattern look or my point at all! Thank you this was exactly how I feel and better than I could have articulated it. We can have this debate. It's an interesting one to me, but probably not to most so I didn't want to reply in the main thread. Why is 25" at BWI in a -AO Nino unrealistic? That is actually below average snowfall for a nino! Discount the "nino" part and 25" has happened once every 2.9 years on average in Baltimore! So over the longer period of record I am talking about something that should happen about 1 in 3 years. The next part isn't really "fair" to you but this is a larger forum wide discussion, not a personal one, but there are 2 threads of thought going on simultaneously here. I am both analyzing trying to get a big snowfall season, but also trying to prove my point that I believe our snowfall climo has degraded more than "some" want to admit. You can't have it both ways. Not you personally but I mean they can't try to argue I'm crazy and our snow climo is fine and its just been bad luck...then someone else say its not fair when I hold us to the same snow standard and expectations we have had historically. I agree with you that its likely our normal is radically lower than the numbers I am quoting but that kinda proves my other point and many are not ready to concede that yet! Can't have it both ways. Lastly, there are likely so personal preferences here that lead to this conflict in expectations. One is my location v yours. Some of the best seasons for 95 and especially NW of there aren't so good for you. Your location near the coast makes a progressive wave gradient pattern actually more appealing. It eliminates the boundary layer temp issues that become an issue in coastals and blocking patterns. But for places like me those patters are absolute utter BS crap on a stick. They are mostly SWFE so I lose the upslope that makes my area jack in almost any coastal storm. And they are unlikely to be storms that hit in strings so they never lead to an above avg season for the whole region. Your area can luck into an above avg season with one or two hits because your avg is so low but on the whole those types of patterns will never be a region wide big snow year. Given my location why would I want that type of pattern? I will never get anywhere close to avg snowfall in that kind of look. Neither will IAD or Winchester or anyone NW of the fall line. Lastly, its about what I like to track. It's not just about snow to me its also the fun of the chase and tracking. Progressive waves in a gradient pattern suck. They are no fun to track. You can't really identify a discrete threat from any kind of range and they are really a fluke thread the needle thing. And in the short range they are boring. They aren't dynamic events. There is no deform band to try to nail down, no changover line to get right, no thunder snow to root for. They are just awful from a tracking stand point. You are entitled to any expectations you want. I don't mind your expectations. But no I won't ever be happy if the best we can do is root to get lucky once in a while in a progressive wave pattern. That is no fun for me on any level. Frankly if we come to the point where I accept that's what its come to and the time of getting epic periods from a -NAO eastern trough pattern are gone for good...I will likely just stop actively tracking. I spent the good part of two winters in NC many years ago and I didn't bother to track. Ironically they got more snow when I was there those years than we have here recently, but I didn't waste my time tracking weather in hopes of getting one or two random snows. I knew how unlikely it was to really get much snow so I didn't waste my time. I will come to that point here pretty soon if things don't turn around. I am already not tracking nearly as much as I used to. I never stay up late anymore for a model run. I sometimes go a while day without doing much analysis myself and just check the posts here. I am already starting to lose interest. ETA: I don't need to have an lot of snow every season to stay interested...not even every few years...but if we can't get a truly snowy period or an HECS level storm (one or the other) at least a couple times a decade then I'll lose interest and find other things to occupy my time until I can move somewhere that does.

I don't think so because the whole pacific is warm around it, which is also making the Nina's worse since it increases the gradient which is more important than the raw anomalies.

It's subtle but the EPS look is way more workable than the GEFS. Subtle longwave changes make all the difference for a specific location. I would still argue that look isn't great if we want a big season, but its certainly workable if we just want to get some snow. The GEFS look is pretty bad.

We should take all the comments regarding our feelings towards the pattern to banter or my “will it ever snow” thread. I didn’t mean to start this bickering. I was trying to point out what our snowy patterns look like and what does and doesn’t work if we want a 25” plus season. I didn’t mean to start a debate about how we feel about that or what is or isn’t realistic expectations. I’m interested in that debate too but it doesn’t belong here.

Because the analog set limits you to 20 seasons and only goes back to 1950. I would have gone back further if I could. If we use Baltimores full period of record it’s happened 49 times in 140 years for an average of once every 2.9 years. That’s even more frequent than the number I quoted. I promise I was not trying to skew the data. I just can’t do an analog set for the whole period of record but it wouldn’t change the point. If anything it would make it more pronounced.

A couple points to clarify my earlier post. I should have explained in my post the reason a -nao is worse in a -pna TNH pattern is the SER links with the nao as a full lat WAR. I’m not talking about a Nino split flow -pna but a full latitude Nina like western trough. A -nao block works to suppress storms if systems are forced under and through the 50/50 space. But with a full latitude trough in the west systems cut west of the nao and pump the SE ridge. The nao acts like a WAR even if it extends into the nao domain. There is no suppressive mechanism in the flow. A positive nao can be better if the tpv gets displaced south a bit. Then it can act as a suppressive agent. It doesn’t work often. Typically we’re pretty screwed with a western trough but a positive nao with a tpv displaced into Canada to our north is one way that has rarely worked out. RARELY being the key. Second, with a -AO that look isn’t a total shutout look like 2020 and 2023. A -pna TNH +AO is the trifecta that causes most of our total shutout (or close to it say below 5”) seasons. A -PNA TNH -AO pattern won’t be a complete shutout. We likely would luck into a progressive wave or two. Some secondary development. Or a weaker wave timed up behind a cutter. But it won’t lead to a snowy winter on the whole. It’s not as bad as 2020 or last year but it would be a hell of a way to spoil a -AO Nino and turn what would normally be our best shot at a big snowfall season into a below avg one!

I am fine with it either way. It doesn't bother me the way it is now...but I get the sense it does bother some. Especially when there are some threats day 5-10 that have potential and they have to see pessimistic posts about day 15-20

see my post above

I wanted to illustrate what I am talking about regarding what we want and more importantly DONT WANT regarding the longwave patter for snow. Instead of cluttering up the thread with a bunch of replies I thought I would lay this out in one thread with evidence to support what I am saying. This is the mean H5 for every 25" snowfall winter at BWI since 1958. From 1958 to 2016 there were 19 of those, a mean of 1 every 3 years! So I did not only select our EPIC winters...these are basically all the good and great winters. I did not want to be super selective. These winters used to happen pretty regularly. This is the "what we want" pattern for the winter Try to ignore the overall heights because they are skewed colder by the years prior to 1980 when heights in general were much lower on average. But try to look at where the lower and higher heights are centered and angled...what the longwave pattern looks like. To make it even easier I pulled out the years prior to 1980 below...still the same pattern though just with higher heights in general so closer to what it would look like today on guidance now. The major take away...we want the lower heights centerer SOUTH OF US...not to our northwest. We do NOT under any circumstances want lower heights centered in wester canada, that's where we want a ridge. All this canada is warm talk is annoying because Canada is warm in almost all of our snowy winters. We are way to far southeast and close to the Atlantic and with Gulf influence for a pattern with a mean trough position to our northwest to work for us. Look at the current day 16 GEFS It's the antilog to our snowy years...everything is opposite where we want it in terms of the trough/ridge axis in the long wave pattern. Frankly that is even further NW than Detroit wants...this is the analog for Detroits snowiest winters... Even they want the trough axis and the ridge in the pac centered significantly further east than the guidance is showing. That is probably a great look for Chicago and Green bay on the GEFS. Also...some of those years for Detroit are ok here...we did ok, not great we got scraps compared to places to our NW but ok...but notice the NAO is positive! If we were going to try to make a long wave pattern with a trough to our west work we want the NAO positive! Our best chance is to have a TPV over us and once in a while it gets displaced a bit south and can act to suppress the waves. That's how 2014 worked! It's still super rare and isn't likely to lead to a good year...but at least an OK one, but a western trough with a negative NAO is actually EVEN WORSE! Lastly...2014 is an example of the very very rare case a trough to our NW worked out but notice the differences here Look at the NAO domain...again a negative displaced south to suppress the flow...we have a big positive there now, not going to work. And look at where the pacific ridge is and the downstream trough over N AMerica. There is a central pacific trough not ridge its just displaced southwest of where it typically is in our best years. This year was an anomaly. It's the ONLY season in the analog set where BWI got 25" of snow with a trough centered to the NW of us. THE ONLY ONE. And it had those very specific and odd features to go with it. A full latitude EPO/PNA ridge and a displaced TPV in eastern Canada. So we do NOT want a trough centered to our west under any circumstances. Only one time in 70 years has it lead to a snowy year and that season we had two other very specific features that we do NOT have this year. We want the trough to be centered south of us with higher heights in western canada! The complete opposite of that look some are saying is ok.

NOOOOOOOOOOOO

That's how I took what he said...but sometimes it's hard to translate "Chuck" into human language Sorry for my mistake...

@stormtracker @CAPE @WxUSAF @Terpeast @Bob Chill Just a thought...what's your opinions of splitting this one thread into 2? One devoted to pattern discussion beyond 10 days...and one devoted to specific threats between day 3-10. Right now the two are lumped together in this "long range" thread and I think that can get annoying for those that are only interested in the analysis of the specific threats and don't want to have to deal with the super long range pattern discussions.

It did but it also had a raging positive AO. That combo is flatline to our winter snow chances. That's why I called TOD on the winter before New Years that year. It was over before it started. With a -AO there is slightly more variability to the pattern. It will dump cold into the CONUS but always to our west. It's a frustrating pattern because it will tease us in the long range but without a mechanism to suppress the storm track (the NAO there is more a WAR than a block) almost any amplified storm will cut west of us no matter what it shows day 10-15. We probably end up with some snow from some random progressive waves or a secondary development after a rainstorm. It's not a seasonal shutout kinda look that it would be if the AO was positive, but its definitely not a good look or one that could lead to an above avg snowfall year.

There is plenty of time for it to change, but he is correct that the wave spacing as shown on that run won't work.

Yea and yes, but we managed snowy winters in previous -pdo cycles. They were worse than +pdos but not nearly as bad as this current one.

Excellent post. But my example was a 4-8” storm and yours was a slushy coating for most. I guess I should have been more specific. Remember when we could luck into a warning snowfall in a bad pattern if enough meso factors broke our way. In my case study of all the 4” plus bwi snows I saw plenty of lucky fluke’s in an otherwise god awful pattern. You know what all of them had in common? They were a long time ago!

That is textbook -AO/-PNA/TNH

In the Macro the -PDO TNH loading pattern....with the dominant features being the pacific ridge, -PDO, SER/WAR. There has been some variability...mostly due to the AO. When the AO is positive or neutral its been an utter torch disaster with no cold anywhere south of Hudson Bay. When the AO goes negative we get cold dumping west of us and we can sometimes luck into a random progressive wave. But that is NEVER going to be a path to a snowy winter...the best we can hope for is to get lucky a couple times with waves and avoid a total snowless winter...but forget ever getting a legit snowy winter that way. 7 years is long enough to know what that is going to look like...the goalposts in that dominant longwave configuration are established and their between bad and worse. No animosity here...you can root for whatever you want...but I truly don't understand why we would want to take our chances with more of what has lead to the worst snow fail in history. ETA: remember I said anything less that above avg snow this year given the potential is a total and udder disaster fail. So when I say fail I am not saying no snow like last winter. I don't think that is on the table. I hope anyways. But if we revert to a -PDO TNH dominant pattern the thoughts of a big finish our off the table and that is a fail to me. So maybe we just disagree on what an acceptable outcome for this winter is. Lastly... to be fair, MAYBE adding a nino stj to this equation would increase the potential some...MAYBE. It didnt help much in 2019 once the PNA TNH took over...we were left trying to get scraps from progressive waves and it was mostly a fail. But MAYBE...id still rather not test that out.

it's marginally cold enough... by like the 5th wave since the long wave pattern actually changed. I say marginally because yes if everything goes perfectly wrt surface and upper level track and heavy enough precip...yes it will snow. But even then we have no margin for error. If the storm cuts at all...forget it. There is no depth to the cold even by then, we are left with a thread the needle scenario despite being about 10 days into a better longwave pattern by then. It's not horrible. I still expect better looks later. But its disapointing a little that even after a week and several waves the depth of the cold is barely good enough, IN A GOOD PATTERN! We used to be able to luck into snow in a bad pattern now we need to luck into it in a good one. The debate about the GEFS is silly because I think its just wrong...but I am annoyed by those that see the exact same long wave pattern that has been an utter and total worse snow period in our history fail for 7 years and are like...in my best Tommy Boy voice "hmmm its not so bad".

The period you’re referring to has been the least snowy in our region’s history. Why would we be rooting for that pattern to continue and expect better results?

Sorry I didn’t mean it to be snarky towards you. The point I was inarticulate in making was that even in a pattern that’s almost exactly what we wait for, in January, we’re looking for 10,000 things to break our way to be cold enough. That’s what it’s supposed to be like in a bad pattern. Remember when we used to actually luck into snow in a bad pattern. Like Feb 1997. Go look at that week where we got a 4-8” snow. It was a garbage pattern. But a few things broke out way and with a thread the needle perfect SW pass we got snow in an otherwise warm crap pattern. Now every crap pattern is a torch straight from Hades with no hope of snow anywhere within 500 miles of here and we need a million things to go right each in a great long wave pattern. I still think we get to better chances later but the early returns are disappointing. I didn’t say it was correct or permanent. I simply said that look right there wouldn’t be conducive to snow here. I haven’t did into today’s gfs package. Yesterday’s was troubling in that at the end the forcing was in a bad place and the pacific patter was regressing. It was not heading the right way. But I said I think it’s wrong. Todays run looks somewhat better but still not good at the end.

That’s slightly better than yesterday but still garbage. That isn’t a nao block it’s a WAR that extends into the nao domain. We’re on the eastern edge of the trough with no mechanism to stop any amplified wave from cutting. We could hope for a progressive wave but any strong storm would be rain.

When we get this… and it’s just not cold enough…I dunno am I the crazy one? And yes I know we’re recovering from a torch but isn’t that part of this same rinse repeat cycle where any warm up is a compete torch then when we get a better pattern it’s too warm. If it takes 2-3 weeks to recover how often do we get a good pattern to last that long? and if Mars is in alignment with Jupiter and the full harvest moon during a solar eclipse then maybe…

That ridge in AK and trough to the west combined with the -AO argues the trough should broaden and extend east.

It was an improvement but remember you want to use the probabilities not the mean to bet a better idea. Last year I did those probabilities after each run because the mean maps give an inflated idea that makes the ensembles look like they are predicting snow when they aren’t. Them people claim they suck and are always over predicting snow. for example the probability of 1” is only about 30% on that run. The mean is skewed high by the big hits. That was an improvement though so worth noting. I meant game over to get a truly snowy winter. Game over for my winter forecast. Not game over to get any snow at all. We would be back to the same place we’ve been the last 7 years trying to make a horrible long wave pattern work and praying to get table scraps and if we’re super super lucky maybe enough have an outside shot at having a not horrible winter. No thanks. I do think it’s wrong. But I took issue with some posts trying to minimize what the gefs was showing. Some “it’s not that bad and would be temporary” comments. It was that bad and wouldn’t be temporary. It wasn’t the transient ridge issue Chuck was freaking out about. That period came a week before the period we’re discussing. The forcing at the end of those gefs runs indicated the tropical forcing was stuck in the MC and going ape. Same issue we’ve had. The pac trough was retrograding completely out of the picture and the central pac ridge was going nuts. Also later when it updated the gefs extended confirmed my suspicions and locked that in for weeks! It was an awful run. And it wasn’t nearly as bad at day 16 as the runs were discussing! I was trying to drive home that even though I think it’s wrong don’t sugar coat the turd the gefs was spitting out. And even though I think it’s wrong I don’t want to see anything showing that crap look. That h5 is what I wake up at 4am screaming “good God Nooooo” No I love snow. But I do want to lay the groundwork so if we do fail I don’t have to hear more excuses from the “it’s just bad luck stick my head in the sand” contingent. We’re already in unprecedented snowless territory. Every major east coast city has set a bunch of snowless streak records recently. The obvious thing tying all this together is tap dancing on our face and some are like “we just can’t know”. So no I want us to get a ton of snow. But at the very least if we don’t I want the consolation prize to be that I don’t have to hear anymore “everything’s fine” excuses. EXACTLY…that’s the best example of what I don’t want. We had some chances in Dec and early Jan that year before the Nina pac state set in. And in a Nina type pattern often early is our best shot. We had some snow and chances early in several of our awful winters recently. At least west of 95 did. It’s been too warm early in the coastal plain. But once the pac ridge took over in January it was game over. 2019 that one fluke storm that bullseyes DC came early Jan during the transition. Once the pac ridge went nuts we were left trying to get those progressive boundary waves that mostly went northwest of us to work. We got some snow. But the chances of a good Nino like period or a hecs were over. Lastly I think this is moot. I Think it’s wrong. But don’t pretend that look wasn’t a total disaster if we want any chance of ever getting a classic truly snowy winter where we aren’t just praying for progressive wave table scraps like the last 7 years. I’d rather fail like the eps weeklies with too much Nino! At least that leaves the door open that the pac can be altered!