psuhoffman

In both 2019 and 2024 the epic blocking looks would start to degrade before getting inside day 10. Usually they were handing out around day 15-20 and occasionally would get inside day 15 but never inside day 10. If this look can survive a few more days without getting can kicked my interest will increase exponentially

100! What has my interest is that we might get a window where there is enough ridging up top that combined with the EPO actually increases our chances of a snowstorm. Enough that maybe we have a slight chance to buck the odds and get that one hit that can make a season. That's realistically all I am rooting for...yea we might eek our way to a few minor events, whatever...but honestly what will make or break this season is if we can get lucky, find a small window, and hit big one time.

Also 2019, its happened a few times lately, it also happened in Dec more recently. The combo of our source regions being torched and mid latitude warmth caused the SER to link up with the NAO block multiple times recently. But we still need that longwave configuration we just need it to not be too warm when it happens, and no I don't know how we magically make that happen...but a pattern that puts us on the backside of a trough with no blocking to hold the cold in when an amplification happens is not a winning formula either.

BTW, given my modest snowfall forecast for this winter...I did not expect nor predict we do get a big snowstorm...or even a moderate one...to get to those numbers we just need a few minor events. But that does not mean there is no chance and that I am not rooting for it. Just because I expect it to be a horrible year doesn't mean I don't want it to turn out better or that I am not looking for the chance it does. Flukes happen. 2000 was a god awful horrible pattern 90% of that winter...it very well could have ended the same as 2002 or 2008 or 2012 as a complete dud...but we got one week with a decent pattern and hit the lottery. I am rooting for that again. That can happen in any year, nina or not.

It's not a block, but it is a high latitude ridge. Yes there is a difference and a true block which always evolves from retrogression or wave breaking is better and that pattern is the best for HECS hunting. But not all -AO/NAO periods come from retrogression sometimes they can evolve from progression of a heat ridge into Canada and those correlate to snow here also! No not as much as the perfect unicorn retrograding block. But a regular good old high latitude heat ridge is still a legitimate way historically for us to get a snowstorm. This evolution is actually almost identical to what lead to the Feb storm in 2006. The pattern started with a full latitude head ridge in the east which got undercut from the west through pattern progression and lead to this... It's a baby steps thing...what we are looking at around New Years would have to be step one of a process that could lead to a favorable snowstorm pattern here a week later IF things go the right way. As for the hyper focus on the EPO... yea it would be helpful if the EPO delivers cold, but there is a reason the EPO along has absolutely no positive correlation to snowfall here! NONE, ZERO ZIP. Actually when I looked at every warning snowfall at BWI since 1950 the EPO of all the major indices I evaluated was the least important. I think more snowstorms happened with a +EPO than negative. The fact is we don't just need cold air, we also need a longwave pattern that favors wave amplification at our longitude! An EPO ridge absent other factors does not do it. An EPO with a positive AO/NAO actually places us in a northwest flow and waves are washing out on approach. It's really hard to get a snowstorm in that look. Worse, without any AO/NAO help when we do get a jet transition and an amplified wave comes along its not going to meet any resistance and so the return flow ahead of it warms our thermals before it arrives...we are too close to the backside of the trough and the warmth is lurking too close to our west for that to work absent other factors like blocking. Cold dry, warm wet. That's a typical EPO driven pattern! No not every single one, once in a while you get super lucky with a year like 2014 or 2015 or some fluke hits like in 2022, but that is the less likely outcome....its much more likely that pattern does not lead to a snowstorm. Just because most of our snow the last 8 years has come that way does not mean its now the best way to get snow...that is the reason the last 8 years has been by far not even close the least snowy 8 year period in our regions history! Yes if that kind of pattern persists over and over and over we will luck and fluke our way to some random snow once in a blue moon...but it will continue to be the way it has the last 8 years with below avg snowfall years and scraping by with long stretches of frustration. An epo driven pattern is not going to be our most likely path to breaking out of this and having a truly snowy period or getting a legit area wide snowstorm. And sure we take what we can get, if scraps is all we can get eat them....but we don't control any of this so why not root for more? It's ok to realize we probably aren't going to win the lottery, but its ok to root for it! Lastly, if we get a pacific to atlantic ridge bridge up top (and those are rarely blocks) and its just not cold enough...the pattern isn't the problem...its just become too warm is! This is a matter of degrees, sure you can do the whole move the goalposts thing and say well...if that is too warm now we also need the EPO ridge AND we need there to not be a torch period ahead of the longwave pattern, and we need cross polar flow and we need....OMFG at that point it sounds like we live in Atlanta now and the truth is its just not gonna snow much and its probably not worth even tracking. I mean even in Florida there is some checklist of anomalous factors that if they all lined up could lead to snow...but the point is their checklist is 25 things long and so its just rarely ever going to happen. If our checklist starts to go from 3 things to 8 or 10 or 15 at some point we've entered the "its just not gonna snow much" territory. But just because we have a thermal issue now does not mean the AO and NAO are suddenly less important, there is no evidence of that...it just means we are snowing way less. We still need those other factors to line up to have a good chance of a snowstorm...we just also now need MORE.

2021

@WxUSAF @Terpeast We’ve discussed evaluating how much snow we may have lost due to warming but I’d love to see if a reverse method was used to assess how much snow would have fallen around the area in 2020-21 had it been the 1960s. I say that because there were several times that winter analogs from the 60s were at the top. And it was a pretty good pattern with several perfect track rainstorms. I got 50” up here because my boundary was just cold enough with elevation. The boundary is waning the fastest. I’m curious to see if that was supposed to be one of the good winters in an otherwise bad period. Overall the pattern has been shite recently but we’ve always had a skewed snowfall distribution with big years surrounded by crap making up a large portion of our snow. If we were to lose just say 1/3 of those big years it would have a catastrophic effect on our snowfall. We had this mean H5 for the core of that winter and only higher elevations cashed in! Thoughts?

It’s been requested I keep negative posts not directly about the current pattern here so here goes… CBM: Yes the negative anomalies are centered over us and have been…but it’s not enough. I’ve wondered this when seeing some of the isolated cold pockets out west the last 10 years…”would that even do it for us if it was centered in the east”. As we warm these tiny cut off pockets of cool just aren’t gonna cut it. Yea we could get lucky if every synoptic variable is perfect but most of the time it’s chilly but the cold airmass doesn’t have the depth necessary to withstand the WAA and return flow ahead of a wave strong enough to give us a decent storm. The only time it’s cold enough in these shallow cold pockets is on a NW flow. So we get cold dry warm wet. frd: exactly but the issue is if you look at the loading pattern for all our big snows that feature a trough just off the west coast and a split flow which floods Canada with pacific maritime. Canada was warm during almost all our snowstorms and that’s why almost all our snow comes with temps not too far below freezing. There are rare exceptions but warm everything just a few degrees and DC loses the majority of its snow! The issue is these pacific maritime intrusions used to being +5 or +8 not +20! Recently the pacific intrusions have warmed out source regions so much that even when we get a perfect setup it’s too warm. We have to hope this changes when the pdo flips, and I’m hopeful that will help. But I’m not sold the pdo is 100% of the issue.

I remember people complaining because the snow melted fast because it got into the 50s 3 days after the storm. Imagine that now. How the mighty have fallen.

I’m sure he could throw that in for free, what with the holidays and all.

Unfortunately it was sponsored by a Nigerian prince and is currently under embargo due to an unfortunate technicality with his treasury. He told me if you wire me 10k he can clear it up and he will send you a million dollars and release the images!

Ya we are talking about the same thing just using different terminology

That’s realistically what we’re rooting for in a cold enso. There were two examples in 50 years with more than one significant snow. 1996 and 2014. Those were unicorn fluke season. For the rest of the cold enso we hope to get lucky one time. March 99, Jan 2000, Feb 2006, Jan 2011, March 2018 it can happen. If we don’t get that one lucky hit then it’s probably gonna be a total dud like 2008, 2012, 2017, 2023

The scoreboard right now is kinda my point...we've been in a TNH EPO driven cold pattern since Thanksgiving and we have absolutely nothing to show for it outside the higher elevations. We have to get the trough axis further west and some STJ injected into the pattern or its likely to be more of the same.

Obviously this is my bias but it wasn't really that good up here... But this is where I am coming from. In the last 30 years there have been 17 cold enso seasons. In those seasons I have had 17 snowstorms of 8" or more. So we are not talking about some super rare thing here, it's not impossible. And I checked, all of these also featured accumulating snowfall into the DC/Balt area and most of the were warning level there also! So this is what we are looking for, and it doesn't look all that different from what we look for in a warm enso...the fact is to get a 8" snowstorm we need the same things whether its a nino or a nina, its just harder to get in a nina so it happens less often...but not NEVER just less. So my point is, we need to hope we get a transient nino look and luck into a snowstorm during that because that is how we get snowstorms in a nina, not typically from a TNH EPO pattern, those are cold/dry most of the time.

Feb 2006, the lead up to the storm that dropped 10-20" across the area. Probably our second best cold enso snowstorm of the last 30 years.

Everyone is free to root for what they want. Keep in mind we have different situations...where you are actually has a significantly better chance of getting lucky in a EPO TNH pattern than 95 west. So some of what I am about to say is very specific to 95 west... but no thank you on the TNH EPO thing...because its damn near impossible to get a snowstorm in those patterns here and I root for snowstorms not pity flakes. That is me, everyone is free to be happy with some mood flakes, but for me its snowstorm or bust. I don't mean HECS, a 6" storm can be fine also, but I am not in this game to track 1-2" naissance events. Frankly if you tell me now that I will get 12" the rest of this winter and it will all come 1-2" at a time, I would say forget it I would rather just get shut out and not waste my time worrying about it and move on with my life. 2023 when I got absolutely no snow was much less frustrating to me than 2009 when I got 20" but it all came 1" at a time and I was left wanting to punch cute woodland creatures by the end of the year. So I will take my chances with the Nino split flow look, because thats how I actually get snowstorms. Just because it's getting warmer does not mean suddenly there is some other path to getting real snowstorms...if it gets too warm for that to work it will just mean we dont get snowstorms anymore. But I am not rooting for the wrong pattern just because the right one might not work anymore...I'll keep banging my head into that wall until its proven that we've warmed too much for it to work...and at that point I will check out completely and not look at all anymore same as I would if I lived in Florida in winter.

Of course...we have had snowstorms in a nina, and most of them have some STJ influence. It's really hard for us to get a significant snow here from a pure NS wave. It's just, unfortunately, not nearly as common in a nina, but not impossible. Here is an example. One of our best cold enso snowstorms of this century. It was a hybrid of a digging NS wave phasing with a STJ wave.

Let’s hope the extended guidance isn’t correct. Yes it’s a cold look but assuming those day 20-30 looks are correct I don’t like the long wave configuration at all to get a meaningful snowstorm. Maybe a clipper or a weak wave but there is no STJ and the trough axis is too far east to amplify a NS wave in time. It would be a frustrating pattern imo. Let’s hope the day 15 is correct and it doesn’t roll forward to that.

My thought process in ignoring the extended guidance is that over the last several years they’ve had a tendency to want to revert the pattern to a generic enso look almost immediately so that by the end of week 3 they always look like whatever the mean composite for the current enso is. That’s not been working out so well though and twice recently it completely busted when those products wanted to establish a canonical Nino pattern. Will that day 15 Nino look immediately progress towards a classic Nina pattern by day 20, maybe. But based on recent performance and trends I’m not assuming so.

That is more Nina, but I'll be honest I'm not wasting much time on the extended post ensemble guidance, the skill beyond week 3 is so low it's really just for fun. But the genesis of the January pattern is now within range on the end of the ensembles. This is the look that had my interest on the EPS and its been there for a few runs...GEPS also...a little less so on GEFS but I think its just slower to get to it. This is more so a nino pacific look, along with the correlated Atlantic side blocking and a split flow across N Amer. This would be a rare look in a cold enso season. But enso has not been as reliable lately so who knows. I am not making any definitive calls on anything yet, this is all way way way out there...but I've taken heat for pretty much debbing on everything this season so far...so I thought it was worth it to say this is the first time I've seen anything that at least peaked my interest and made me take a second look.

One thing I find "interesting" is the guidance right now for early January has more of a nino than nina look. Take that for what it's worth...something to keep an eye on as it get's closer. If we can get the high latitudes to cooperate and even just some STJ involved it would increase the potential significantly.

Fair enough. I get it. I miss the good old days when we had winters where I could spend a lot of the time doing analysis of a specific legit threat rather than looking at day 15 height anomalies and saying “still sucks”. All I’ll say is this….keep in mind I’m actually still too optimistic. Trolling would be if I intentionally was making things worse than they are. But I can’t remember the last time I said some pattern sucked or it wasn’t gonna snow and then it did. But I can remember multiple examples in the last 5 years where I said I was exciter and thought we had a good chance and it didn’t snow. I still over predict snow.

I’ll try, but most of the time I’m not trolling it’s just whatever statistics or historical analysis I’m giving is so awful it seems like trolling. That’s just our reality though lol.

Legit question not trying to fight trying to learn. The correlation to cold is legitimate, however doesn’t it depend on the mid latitude long wave pattern across North America? That cold does not necessarily have to get directed here, and so how do you factor in that part of the equation? Thanks.