psuhoffman

It won’t undo the misery of this dreadful winter...and I don’t know what the score changes too, depends on how much and how long the snow lasts I guess...but a snowstorm would make me happy and I would enjoy that day and that’s all that matters to me. The past is done. I can’t change it.

So this is super low odds, in a good year it wouldn't even be worth mentioning it...but the scenario the GFS has shown a few times now centered around day 12 is showing up on some other guidance also. The euro control gets a couple waves through the area around then with a somewhat similar evolution, getting an initial wave up into the 50/50 area and then pinwheeling something into the east behind it. There are several members of the GEFS and EPS that do the same. I suppose its just enough to say its possible and not completely crazy. There seems to be some hints that perhaps there is some opportunity for something around March 7-10th.

What the GFS is doing (more so at 0z but somewhat at 12z also) is a good example of why shorter wavelengths in March can create fluke events. That said...this exact result is still unlikely, and even if we do get a system to track under us I am on the record saying its going to be rain...that is simply the best way to end this season with the most possible damage and pain possible. But this is a perfect illustration of how March can create weird solutions. This looks so familiar...same setup for the whole winter...with the crap pac setting up a trough west ridge east configuration and no blocking up top to help force a system under us. But despite the same look up top and in the pac the shorter wavelengths make it POSSIBLE, not likely but physically possible, for a system to track under us. The first wave slides into a 50/50 position which is still critical, and likely an error because if that first wave ends up anywhere else or at any other time...the whole thing doesn't work. But even if we had that perfect timing in January this would never work. Look at the short spacing between waves which makes this whole thing even physically possible. During mid winter that look in the pac would drive a super ridge into the east and its game over no matter where that first wave goes. The possibility of tight spacing and systems to cut off because of it creates the chaos we need to even have a chance at a fluke in such a hostile pacific base state. It's still unlikely anything works out...it would take a lot of luck with multiple moving parts, but its physically possible.

my perfect track rainstorm is there on the GFS again lol

July is going to be hot

Im going to start predicting big rainstorms from 6 months away and then declare myself a weather god

Thank you. 2 thoughts wrt what you noticed (I noted it also). First it's hard to draw conclusions about that because what those numbers don't show is the frequency of those patterns. If a pattern is more rare it might be the best pattern but have less instances of snow simply because there were less opportunities compared to a more common but less productive pattern. That said, I do think there is also a bit of "too much of a good thing" going on with a -EPO/+PNA full latitude ridge. In a vacuum a -EPO/+PNA/-AO/-NAO are the best phases of each of the 4 major indexes. But when in combination it's not always that simple. When we have a really strong -NAO for instance, some of our biggest snowstorms happened with an unfavorable PNA/EPO combo, but in reality that "unfavorable" pattern out west trying to force ridging into the cold locked into the northeast is what created the big storm. Without that we would have been cold/dry with a weak wave running off the southeast coast. Time of year also matters...we typically need the epo/pna more early in the season and the nao more late. Without any NAO help...by far our best look is that east based EPO ridge nosing over the top creating a broad flat trough under it across the lower 48. The NAO changes the equation. The more blocking (especially later in winter) the less we need EPO/PNA help. Enough blocking later in the season and we actually dont want a big wester ridge. So there really is no one perfect look that is universal across the whole winter season. That study I did was just step one is a larger plan. Right now I have no time for anything. My less frequent posting lately is not just because the weather sucks... its more that this is a busy time of year for me. December/January I have a lot of free time. Between Holidays, end of semester and PD breaks there, and testing I have a solid 2 months with not much going on other than my normal teaching duties and even those...I only have a normal class to plan for or stuff to grade about half the time. Right now is one of the times of year I am slammed with observations, curriculum planning meetings, summer school planning, bridge project scoring, Test prep planning, debate events... I just don't have time. But I have way more in the plans. I just found out I might be getting a rather significant increase in my responsibilities wrt to my summer position so I may not get to all of this but I should still have more time to at least start this list. In addition to what I did in December, I want to do a similar study for our area. Then I also want to look month by month and break down the dominant patterns from 1950 on to see the frequency of each pattern. I also want to break down those splits by month to confirm which patterns work best by each month. Once done I would be able to determine what the odds of snowfall in any given pattern are (roughly) by month. That would make what I posted here a lot more useful. But that will take a lot of time I don't have right now. If I don't get it finished this summer I probably will next December during my next "down time" period.

Fluffy Flakes sounds like a delicious breakfast cereal

I know YOU, and most, know that. But I wouldn't want some to misinterpret your first post to mean "just look at the AO". There are definitely some situations where the AO is the key. This is one of them. But then there are times the AO is less stable. Or years like 2014/2015 where a perfect EPO can overcome a +AO. Or more often then that...a short duration cold/snowy period during an overall warm +AO year. No argument from me that the AO is one of the most important, if not THE most important indicators for snow here....just that its not as simple as "just look at the AO". I wish it was. My comments were more for the new posters that might read that and get the wrong idea.

Models are getting better at this

And there it is

I’ve never been more sure of anything. The one thing we are great at is epic fail.

No we will get 2-3 teases where it is cold enough but storms track just to our west as the pattern transitions. Then exactly when it’s simply too late to work we will get the totally perfect coastal bomb that would have been 50” if it was one week sooner but will just be rain mixed with just enough slush bombs to make it hurt more.

Hints of the tpv breaking down at the end of the gfs. Just in time for our 37 degree epic perfect track phased bomb rainstorm

So the obvious issues of the pac and AO have been covered...but there are transient troughs making it into the east now due to shortening wavelengths and that’s our “fluke chance”. But another issue muting those odds is that the next 2 troughs (on guidance at least) amplify and stall to our north and do not progress east. It’s much harder to get a follow up system to amplify under a system than behind it. It’s not leaving enough space. Then when the trough lifts it does so quickly and to the north instead of a progressing east which also limits the chance of a WAA wave on the tail of any cold shot. That progression is the fabled warm wet cold dry we love so much.

Yea I nailed that the sun would come up this morning...everything else is details. I’m being a smart ass of course and you’re right but in my experience the cfs gets the whole picture correct so infrequently, and is so god awful with major pattern drivers like the mjo, that it’s useless.

The only time I even look at the CFS is when it came up in discussion. It’s useless. But simply using the AO isn’t going to work past a week since the current AO doesn’t have much predictability past a few days. It can flip quickly sometimes. Now certain patterns that create stable feedback loops like the current pac/AO combo can suggest persistence. But simply using the AO value to predict the next week/month is risky.

If it can happen by mid march we can still score but there is nothing suggesting this It’s going to happen a day too late. You know it.

We are getting an easy snow storm around March 20th What’s going to happen is late March the PV breaks down and blocking sets up but because it’s late March and the mid latitudes are torched by the antecedent pattern we will get a perfect track slow moving coastal 960 bomb that stalls just east of OC and dumps 3” of rain at 37 degrees and mixes with slush bombs at times just to tease us even more.

There is a correlation between tropical forcing, glamm, gwo and the high latitudes. So my guess is they correctly saw those hostile base states. Even ignoring the angular momentum stuff had you shown me the plot of what the mjo was going to do from Xmas to March back in the fall I would have predicted a dumpster fire then instead of waiting until late December to realize we were fooked.

That would help but there is a strong correlation between the unfavorable RNA pac pattern and a +AO so I think there is some connection beteeen the 2. There are some examples of a -AO with this pac but it’s very rare and most of those examples were during the extreme blocking regime that dominated between 1956-1972. Outside that period almost every example of this pac pattern featured a very +AO also.

Not to this level. There are some examples of weakly +AO regimes with a -NAO but it’s nearly impossible to get a -NAO with this strong a PV/AO for the same reason you can’t get a favorable epo in this regime. The tightening strengthened flow around such a strong PV won’t allow ridging to survive long if at all in the NAO or epo domains. The strong flow around the PV will obliterate attempts to ridge there. But also the fact that strong ridging in the NAO domain would likely knock down the AO value some.

Very true...also this level of +AO (record setting) is impossible to overcome on a larger seasonal scale (other than a fluke event) because to get this strong a AO it’s very unlikely we get the epo ridge needed. A strong east based epo ridge naturally reduces the AO value some because it enchroaches in that domain some. Plus this strong a PV will strengthen the zonal winds around it blunting attempts at any ridging either in the epo or NAO domain. So while we can sometimes overcome a +AO in a year like 2015 with a monster epo it’s probably not possible to overcome this level of consistently 3+ stdv AO.

Good. Obviously the rest of us were put on this earth just to make you feel better...so that’s all that matters.

The whining and complaining is one thing but acting like a jerk is uncalled for. You learn a lot about people from how they behave when things aren’t going their way.