psuhoffman

We’re not gonna make it

If we want hope we could always get lucky with something like 2000. It was a Nina but I think the same type thing could happen in a neutrals also because the snow we got was just pure luck. The pattern that winter was predominantly a dumpster fire shit the blinds pattern. There was only a 10 day period the whole winter with any hope at all of snow. And it wasn’t even that good. It was just ok. extremely east based -NAO, mediocre pacific and AO. It’s not awful but that doesn’t scream great chance of a big snow. And that was the best we got all winter. The rest was total no hope garbage. But we got a few waves during that window and they all hit the region and one was a blockbuster! And a positive bust no less! But it was just pure dumb luck. If we replay that same winter pattern out 100 times 99 end up below normal snow and 70 probably end up like 2020! There is a lot of luck involved. Even in the worst winters there will be a couple chances. Get lucky and they hit and we avoid a dumper fire no matter how bad the predominant winter pattern is.

I’m with you 100%. There are actually two predominant types of Nina’s. A more flat pacific ridge with a +AO and those are dumpster fires. But Nina’s with a more poleward ridge and a -AO are cold. We still struggle wrt snowfall due to the lack of STJ and NS dominant systems so we get miller Bd to death. But they’re way better than neutrals during -pdos tend to be.

There seems to be a correlation with enso neutral and +AO in strongly -PDO regimes. That might explain why they all end up so bad wrt snowfall. In some of the Nina years the pacific ridge actually extends into the AO domain and sometimes even links with the NAO. We still suffer from the lack of STJ so they haven’t been particularly snowy but they are close and “snowier” than the neural years.

Going back to 1950 there have been 7 enso neutral winters during a deeply -PDO regime. All 7 were well below average snowfall at BWI. 2020 was the most recent example. If we end up enso neutral it would reduce the expected snowfall for BWI from 11” to 7” using the method I’m experimenting with. Assuming all other factors stay the same.

Our last 2 neutral winters were awful.

2001 was a decent winter up here, but the 3 largest snowfalls that winter here were all very marginal. Two were rain to snow events and one was just wet snow the whole time. 2 of the 3 were mostly rain in DC/Baltimore. If you increase the temp at all...you can probably take away a significant % of that seasons snow up here.

Honestly I’ve posted that clip multiple times over the years when people ask for a prediction. It’s a running joke. I’m sorry if it came off as an insult, I didn’t intend it that way.

Are you ok? This doesn’t seem healthy. Whatever I did to you I’m sorry. I know we’ve had disagreements and debates but I don’t know you, it’s not personal, and I wish you no ill will.

Btw anyone want to chime in about something not getting much talk but that’s equally part of our recent snow issues. The nao since the 1960s is trending more positive. There are up and down cycles but since the 60s each positive is more positive and each negative is less negative. The fact is our winter months are now in a positive nao state about 80% of the time. That’s a problem for our snow. I have a theory but I kinda want to hear other hypotheses

@Terpeast I’m also glancing at pre 1950 data and it seems to support my idea of analogs working better if you can superimpose the larger hemisphere cycle. But it’s problematic because take a similar cycle in the early 1900s. First of all there is evidence the PDO is trending more negative during negative cycles lately. But also that was a much colder regime. So a 9 year period that produced a 17” avg at BWI seems ok but that’s coming off a period when BWIs avg was around 27”! That 17” would be more like 12-14” today. And if the PDO is in fact increasing its variance maybe that knocks it down to 10”? But in general I think the evidence is it’s really hard to get a truly snowy winter in this type cycle The only catch to this method is we can’t predict 100% when the cycle might flip and if it does quickly and unexpectedly obviously you bust on the edges of longer decadal cycle changes all that to say if the solar cycle peak lingers and the PDO cycle does flip (we are kinda due) suddenly a year like 2014 isn’t crazy

3 analogs were bunched between 10-14” with one high and low outlier (18” & 0”). I’m tempted to toss the outliers but the 0 is also the most recent analog (22-23). That’s troubling. Once we get to November I’ll try to discern and rank these analogs more accurately. This was just a prelim identification of where we are now. But unless I see signs we are breaking out of the larger long wave pacific cycle we’ve been in since 2016 our upside is severely limited. There have been 3 similar comp cycles (including now) to this one. Defined by me as deeply consistent -pdo overlapping a predominant +nao comprising 23 seasons. I tend to focus much more on the long wave pattern identified by seasonal mean h5 that indexes. But in all those years the largest snowfall seasons were 2 that made it into the 20s. But those both were Ninos. Among all the neutral and Nina seasons we’ve never cracked 20” at BWI during the 3 recorded similar cyles. So the only thing that would significantly alter this would be if there were signs the larger background state were about to change this winter. I don’t see signs of that yet. It could move some of the Nina looks more neutral and that brings some other analogs higher. But the only thing that could significantly improve our expectations would be this most recent northern hemisphere long wave cycle ending. It’s damn near impossible to get a truly snowy winter in this phase.

I have been experimenting with finding a way to superimpose the long term cyclical phases of the pacific and high latitudes over other variables in seasonal forecasting. My methods have boiled down to taking the long term mean 500mb phase of the central pacific, AO and NAO domains and using that to weight analog years produced by other variables. This method significantly improved the ability to forecast the coming winter. For example: last year this new methodology would have given me 4 different top analogs. At BWI the result of the snowfall for those 4 seasons after applying a sliding reduction to older analogs for warming would have given me a predicted BWI snowfall of 10.5". The actual total was 11.3". I found the results to be similar for most years, not to that extreme, but the prediction became much closer to reality when applying this method. However, there is one HUGE catch... we cannot always predict when a long term cycle is about to change. So every once in a while, when a phase change happens during a winter season, it would produce a huge error. As of right now this method has a predicted snowfall at BWI of 10.2". I will update this again sometime in November with an actual seasonal forecast and explanation. Some of the factors and variables could still change some.

Maybe my memory is bad but weren’t they really only about 30 miles west of the other guidance with Helene?

If this exact same look leading into winter was happening during a less hostile pacific and Atlantic cycle I’d be way more optimistic. But one been doing some work on incorporating the long term cycles to other more common analog metrics and it seems applying this method retroactively would have made my forecasts much more accurate. The same factors don’t lead to the same results when supplanted into different cycles. I’m not optimistic that the same set of factors that lead to 2014 would have nearly the same impact now given we were in a generally favorable pdo then and we are in about the worst possible now. That said I don’t expect a total dud either. I think we have enough in our favor (I do agree that the signs indicate a more poleward pac ridge) that we should get some snow. I expect more of a just typical crap v omg this is god awful crap. Something like 2018 and 2022 maybe.

Translated he basically said “we could get a pattern that could lead to either one of our snowiest or least snowy winters ever”. Thanks.

But did you read the thread? He includes 1989 and 2014 in the same analog group. What good is that. One was a dud way below avg year and the other one of the snowiest ever. That’s a completely useless use of analogs.

There was one other moderate storm that just missed also. Those both hit and we remember 2011 as another 1996 type Nina. It can happen. And both of those misses were flukes not typical Nina issues imo. The Dec storm was a gulf stj storm NOT a late miller b but it had a sloppy weird phase at the worst possible spot in its progression. But I am skeptical of getting that cold of a winter in the current pacific cycle.

And Ya'll thought I was depressing

Yup, but while its true, that is kind of a typical issue, and has been, when the mean trough axis is always a little too far to the NW, which even in the "better" looks is still true in this base state. Periods of high amplitude likely lead to storms cutting way to our west...and in lower amplitude we are dealing with a bunch of weaker system running the boundary interfering with one another...but that at least gives us a chance for some snow. Big storms are going to be very hard to come by given the larger scale issues with this base state. Best chance might be getting really lucky with a progressive wave that is simply ridiculously juiced up. We saw that just south of DC in the Jan 2022 storm.

For reference...there is only so much variability to the pacific under this current base state and its bad, so really we are talking about just "kinda bad" v "awful" here...but this was the mean longwave pattern during the 3 snowiest winters of the last 8 years... This was the 3 least snowy winters... Neither of those looks good, which is why we've had no truly snowy winters lately, but the key difference in the "snowier" years was the more poleward extent of the pacific ridge shifting the trough out of western Canada some which allows more cold air transport into our area during transient periods. The less snowy look there is just the total kiss of death with the flat pacific ridge allowing the trough to really get stuck out west and the ridge to go ape in the east and its game over on a seasonal scale!

I mean what are historically "better patterns" are still producing more snow. What little snow we've had over the last 8 years did tend to come during the periods when we had a less hostile pattern. We have not had much luck during the "shit the blinds" patterns. If anything we have had even less luck during those than normal...its almost impossible to luck into snow in a bad pattern now because they are so warm now. The problem imo is we've spend less time than normal in a "good" pattern over the last 8 years, and our results in a bad pattern went from bad to god awful no hope at snow at all due to warming so... Also perhaps the results in the good aren't "as good" but I would want to see more data on that, we've had so few legit good long lasting patterns recently its hard to say that with any confidence. In the end we still want some combo of -AO,-NAO,-EPO,+PNA and we really need 3 out of those 4 to have a good chance at snow. And even if we get 3/4 the 4th cant be like historically god awful or it can still offset the other 3. That has always been true. We just haven't had that much lately because the pacific has been stuck in a god awful phase where the PNA is killing us most of the time.

It's too small a sample size to draw statistically significant conclusions, but just looking at the set of neutral or extremely weak nina winters over the years...it seems that perhaps they take on the flavor of the overall longer term cycles we are in. When we were in a more snowy cold period in general they tended to be better...and when we were in a warmer/less snowy period they sucked. If this is true...it would explain why the last few sucked.