psuhoffman

I've noticed several times over the years its a misty cloudy in Baltimore in Spring but partly sunny with just cumulus clouds out by my house once you get further away from the Bay/Ocean maritime airmass. Kinda opposite the winter when its way more often nice in Baltimore and cloudy out where I am.

I think due to increased mid latitude ridging it is probably true that a SW displaced NAO block runs increased risk of linking up. But I "think" (hard to tell sometimes) that Chuck is alluding to a change from previous norms and he is right that the -NAO as a whole is not reacting the way it used too. I did a numerical comparison a few months ago (even before the most recent NAO fail late winter) that showed our "win" rate in terms of a -NAO producing cold and or snow is significantly decreased over the last 10 years compared to previous. I do think some of that has been many of those -NAO's were SW biased, but some of them were also centered exactly where previous -NAO's that did produce were. So I think both are true...we probably can still do better if the -NAO is centered more towards Greenland but that is kinda sad because some of our biggest storms ever came from retrograding blocks that ended up centered over Canada.

I am cautiously optimistic. But I am guarded for two possible issues. If the nino is too weak does it fail to alter the pacific base state enough. Remember in 2019 long range guidance continued to "tease" that look above all fall and winter and it just never materialized. The pattern wasn't "awful" but it just could never fully overcome the bad pacific base state to initiate the canonical nino look guidance was expecting. On the other hand if the nino is strong...does the subtropical warmth that typically gets injected into that kind of pattern overwhelm everything given the recent temperature trends...and we end up with a 1998 type winter only even warmer. 98 wasn't totally awful once you got into the northwest 1/3 of this forum. And there were some epic snowstorms along skyline drive and out in the Snowshoe and Deep Creek area. And a few of those storms were actually really close even for the cities...a repeat of 98 in the 1998 climate could have produced a decent outcome with a little more luck. There were even a couple of those coastal storms where it was cold enough and then we got unlucky that those were the ones that got suppressed or cut due to an early phase. If the temperatures were still in the 1998 base state I might say lets take a repeat and roll the dice. All it takes is 1 or 2 of those massive coastal storms that were coming every week to be just cold enough and suddenly its a good year. But in this current temperature base state...I kinda doubt we would ever get that pattern to work no matter how many times we rolled that dice. We seem to need true polar airmasses to snow now...we could probably get 10 juiced up perfect track coastals in a row now with a maritime or even modified airmass and it would be rain every time. We really need that epo to help out or the subtropical airmass will likely dominate.

In the winter if the mid latitude storm track is to our north/west we will be "dry". But it wouldn't matter if it was "wet" since most of the time we are also too warm.

For me 2016 was the start of the phenomenon of getting mid winter perfect track rainstorms. We didn’t think much of it because it was a super Nino and that’s actually common in strong ninos. The great storm track can come with too much warmth. But it’s been happening regularly since then also.

I am somewhere in the middle on the 2016 debate. That storm was awesome. I also had another decent 8" event up here in Feb which made a big difference. But at the same time most of the snow in our area did come from one storm...places just north and south of where that storm hit ended up with one of their least snowy seasons every that winter! That is playing with fire putting all your eggs in one basket like that. I don't want our winters to become basically rooting for one fluke like we are NC or something! I would prefer a real winter where its actually legit cold for long stretches and we get multiple events. 2014 and 2015 are the last 2 "real" winters IMO. That doesn't mean I would kick 2016 out of bed...I am not hating on it like some do...but I do acknowledge its not necessarily what I want to root for either.

Don’t mind it now. My classroom has no AC and I have a lot of work to do on the yard, pool deck, and garden the next month and I much prefer 60ish over 90ish

yea but a large number of our forum residents HATED 2016 because other than one storm it was a torch non winter. Not everyone here is happy if our winter is just rooting to get lucky once or twice with a big storm...some actually like it to, you know...BE COLD in winter and actually have snow on the ground more than 5 minutes!

CFS has our el nino! LOL

@Terpeast looking at this made me think about our conversation wrt upstream v downstream cause/effect of the SER. But the gulf/atl isn't really downstream. As any wave crosses the CONUS there will be some southerly flow ahead of it. We obviously need that flow to be suppressed to some extent by the NS or to have cold air in place as that flow gets started...but south of us is off the Florida coast! And as any wave ejects from the Rockies the southerly flow it initiates in the plains is off the gulf of mexico. If those areas are on fire...it just seems logical that the southerly flow will be able to press north more than it would have otherwise. Hence...we get a stronger SER than historic analogs indicate we should have. None of that is to say I think the effect of the pacific doesn't have a part here...yes a ridge in the central pacific favors attempts at a SER. But historically there were things that could mitigate that SER. Lately...NOTHING mitigates it. When there is a central pac ridge its just game over and the SER goes ape no matter what else (-4 AO/NAO even) is going on. I think the warmer SST's in the gulf and SE coast are part of that equation. That added warmth just make sit even harder to beat down the SER and perhaps means we can no longer expect to mitigate a hostile pacific through other means. That is of course problematic since it eliminates another way to get snow and would doom us to atrocious results in even more winters that previously. It would not mean it cannot still snow when we get a favorable pacific though. I do think a favorable pacific can still overwhelm and suppress the SER.

GOOD the AC is broke in my classroom and it does not sound like it will be fixed anytime soon.

The CFSs verification is barely above random chance once past it’s month 1 forecast. Frankly none of our seasonal guidance has much success past month 1! We just aren’t there yet. As for the SER, it did respond to a dying Nina, there is just a misconception that I’ve pointed out before wrt what a Nina heading to neutral means. There is the belief in some circles a dying Nina is good but there is no data to support that. Nina’s that enter neutral by March show no increase in snow in the mid atl v Nina’s that stay strong. Furthermore look at the h5 comp for all Nina’s in the last 30 years… there actually isn’t a strong SER signature. That’s another misconception that a Nina=SER. But look at the enso neutral years following a Nina. There’s the SER! This winter actually behaves more like a neutral following a Nina than an actual Nina. In the end the early dying Nina might have killed our winter more than had the Nina not faded.

@Maestrobjwa another issue with the way you use patterns is not normalizing the data to account for changing norms. This is when you try to use past snowfall results as predictive. Let me illustrate. From 1884-1970 Baltimore never went more than 5 years without a 20” snow season. But that was never predictive that it couldn’t. The first issue is looking at the data closer no one season showed a significant predictive link to the next. The fact it had never gone 6 consecutive years was simply the fact each year had a 58% chance Baltimore got 20” so the odds of getting a 42% result 6 straight times was very low. But once you got to 5 the odds were still 42% it would happen again. It just never had. Until it did. It was only a matter of time! But that fact is even more irrelevant now. Because the odds have changed. Since 1970 it’s happened 3 times! That’s because the odds of 20” in a season dropped from 58% between 1884-1970 to 23% the last 30 years. And running a linear regression shows it’s likely about 18% now! So the odds of going on long runs with less that 20” is increasing because the odds of getting 20” in any given season went from 58% to 18% making that older data even more irrelevant as a predictive factor. So now…Baltimore stands at the end of a 7th season without 20”. And it has never had 8. But that means nothing. With the lowering probability of snow each season it’s only a matter of time. It’s almost inevitable given the current probabilities that eventually Baltimore will get 8 years without 20”. And it’s likely to be next year since the data says in any given season it’s now less than a 20% chance of 20”. Before you jump off a ledge that data is blind to things like enso. Right now we are predicted to get a Nino which would significantly improve our odds. But that’s a completely independent variable. For example if the models are wrong and we end up with an enso neutral next winter then the data says it’s probably about 80% likely we don’t get 20” and go 8 years. Regardless of the fact it’s never happened yet in our records.

you really need to stop attributing predictability and causality to patterns within random chaos. Patterns happen within any string of numbers from random chance. 73 wasn’t really a super Nino so it’s questionable if your pattern is even legit. But a pattern without a logical causality or link is just random chance. There is no logical causality to that pattern you cited. It’s way more likely to just be random chance. Like flipping heads/tails every other flip for a run.

Isn't that pretty much what we should expect any random day in winter?

Everything you say is true, but I am comparing our snowfall now to our snowfall in the past. Not another location. All those issues existed then too but we still snowed more than lately. We never snowed as much as Philly or NY or Elkins WV, those limiting factors you mention were always a problem. But that’s a different issue.

true... but there is a reason for that. Yea a central/west based nino gives us the best chance to get the small minimal amount of cold that still exists at the mid latitudes to be over us (other then siberia which is sheltered from the impacts of the on fire global SSTs) but it does nothing to the larger scale problem that is the reason we are struggling overall, which is if 75% of the mid latitudes are above average temperatures...the odds are already stacked way against us before we even worry about any specific longwave pattern.

We used to be able to do ok in a -PDO. We've had some blockbuster -PDO seasons. 1962, 1966 and 1979 were all -PDO seasons with huge snowfall totals in our area. But notice...none of them are recently. The problem is that over the last 30 years or so a -PDO almost always leads to a horrible snow season.

But if that onslaught only happens once or twice a decade and the rest of the time is mostly snowless dreg horrible periods, it's not worth the investment of time to track every winter and get your hopes up every season. We have already lost several regulars who decided its just not worth tracking anymore and they simply pop in when there is snow eminent but the rest of the time they are gone. I am starting to think they are right...it just doesn't snow often enough anymore to be worth tracking all winter long anymore. The fact is we are wasting our time the vast majority of the time lately.

Scary thing is it was a crap winter for much the same reason...there were several other perfect track storms that winter...but it was just too warm.

No way to know, it’s cyclical but not at predictable intervals. It’s was negative almost 80% of the time from 1945-1980 though. It was then positive 70% from 1981-2016. It’s been mostly negative since.

@Terpeast my post above also highlights what I was saying, that I fear our snow climo has been degrading more than we know because it was masked by the last +PDO cycle. Before 1980 we had a lot of snowy -PDO seasons. Since 1980 a -PDO season has almost always been a complete disaster. But that trend was masked by the fact we were in a +PDO most of the time since then so it didn't matter as much. But if we go back into another period where we have a -PDO most of the time like from 1945-1980 what would that mean?