Typhoon Tip

What we just came through, back in last December was actually a bit more extreme on these ensemble canvases than this -

I kind of would be leery of a warm burst in February to be totally honest. Oh my personal druthers would have me lavishing in it - but the analytical version of self would be wondering, because uuuusually? 3 to 5 days after the warm event, the -NAO is sitting over head like a pachydermal circus mishap... and it starts episodically reloading for 5.5 weeks or something, too - That's what happened in 2018... we had a 70s warm burst, then a couple of coastals in March that I personally would rather not have experience. heh.

Yeah, that 12z EPS mean is a pretty significant continuity break comparing to the previous few cycles, which showed a more coherent pattern change. It wasn't exactly a 'warm' pattern it was signaling, but definitely off the cold throttle quite a bit. This particular 12z cycle mean definitely regresses to cold, however.

Conventionality would have it that going from a 'deep freeze' to a 'relative warmup' back to a 'deep freeze' would feature something taking place along the inflections...

You didn't ask me but ... we're 2 gears in the wave #'s away from this being a better snow year, locally. Uh... what? Basically, thees "+PNA" modes are dubious. As I was defining the design for Go Cart whatever his/her name is ... the ridge component of the PNA's have been very persistently westerly biased. The canonical +PNA is not typically a ridge along 120 W. That spatial idiosyncratic distribution is also drawing the EPO numerics down, which it should. But the overlap is rising the PNA, and we think... great! -EPO with +PNA, what can go wrong? Unfortunately, the idiosyncratic devil is that the ridge position skews/offsets the ability for large scale meridian flow structure east of the Rockies across the expanse of the continent. We end up with a nice N flow tendency in the troposphere along the cordillera out there, but then it turns ENE. There's less impetus there after for the stream mechanics to orient into a more curvi-linear trough. That's the physical manifestation of emerging negative wave interference. But here's the 2 gears aspect: If we move the ridge axis say ... 10 degrees of longitude E, that allows the eastern continent curvature to respond, but this is still too far west ( slightly...). Lakes cutters result. That's gear 1. If we then reposition the western ridge another 10 longitude E again, then the trough anchors more over Lakes, which shifts the storm track more toward the east coast. But here's the aspect that skews this idealized position schematic: the compression in the flow. It's a wild card...one that is a result of cold boreal heights associated with season, pressing S into a mid and lower latitude that is ( more than convention would like to admit ) staggering to recede due to attribution. There was probably no real hope of any kind for those model runs over the last month, that phased those deep scary bombs, to ever happen.. Because A, the trough was too flat from the pattern foot, while B, the flow along it so fast that the S stream is too likely to outpace the subsuming N/stream. It was always model bullshit. This thing for GHD ... is tricky as to how it evolves in "this gear"

We have to be careful with this idea of "other side," too. There really is no 'other side.' These domains are inter-correlated (ultimately), which is purely fundamental; its not like there are solid boundaries in the atmosphere, walling off one identity from another, and then these air masses duke it out via storms. Time is where the relationships are better exposed, as "weather" is just the sound of these domain spaces "communicating". Lag correlation becomes very significant. The NAO, for example. If one did not see the lag-relationship with the Pacific circulation modes, it might actually look spontaneous, as though aroused from some fractal into materializing, and then exerting on the flow ...etc. In actuality, the NAO is a semi-static wave function that is a result of dispersion mechanics, down stream of the Pacific's wave emergence and decay ( constructive versus destructive interference..) - this latter aspect is then significantly modulated by the continent of N/A ... You know it's interesting ... when one really sees and understands that, it's actually less accurate to say the NAO correlates to anything storm-wise. Because it was the Pacific all along. The problem is, we don't have the computing power to see how every decimal point in the total wave propagation in space and time, from Japan to Nova Scotia, will exactly drive the NAO biases... If/when the models are ballooning heights within the NAO domain, the cause for that has already taken place - so it's not really ever a good idea to use the NAO as a modulator. It's more of a beacon for where the PNA was.

I do love it ... thanks for demonstrating someone's actually been not ignoring this when I've written about it. lol - seriously though. Any kind of empirical evidence that supports attribution - to which excessive compression in the winters --> higher velocities is a part ... - tends to get swept under the rug, while our brand of denial is this mind game in here of admitting CC but not allowing it to be causal or a part of the actual weather's make up.

PNA distribution is west biased and has been much of the season – predominantly so … just like the NAO can be east or west.. the correlated weather associated with either is different That spaced PNA doesn’t allow the trough over eastern North America to dig as much you get these flat trajectories… But also while all that’s happening there’s a separate phenomenon related to gradient overabundance, whether you’re in a gradient pattern or not The two of those together are like two strikes before the hitter walks up to the plate

Basically ... this has been a semi permanent feature for the last 9 weeks. It's a colder supply, but unfortunately negative interference heading east across the continent for cyclogenesis. This is the 18z op. GFS. It's Feb 3, and what/if anything that's happened on GHD is behind ... This run places the hemisphere right back in the same mode...

there's a pattern change post the 2nd or so of Feb... it's less than clear what that will mean. there's been gradient looks. there's been warm bursts looks. now, this 12z gfs is trying to change the season to spring across the deep south with a gradient the favors the polar boundary being displaced even NW of the OH River.. 00z Euro has the change in it's extended, and is varying as well .. but it did attempt a big storm on the inflection at 00z around 2nd/3rd.

Agreed, in so far as what this looks like now. However, it looks like it's got some validity, tho. It's just too damn early for the flow to go flaccid - that's a latter March climo... ( but then again with CC who knows, maybe we can chap some denial assess lol ) The pattern foot appears to still want to change beyond whatever that GHD thing is. But so long as there is that ens spatial synoptic positive anomaly up near Alaska like that, there's going to be cold available to the Canadian shield, which is an immediate implication for gradient n-s through the continent.

Yeah, it's interesting how at first there has been a numerical telecon suggestion for and around GHD. Then, the operational Euro opens the bidding up on the 00z run like that. I've always been a fan of that order of events in reality. The math points to a period of time, then the practicals emerge into it. Unfortunately, it's the only member I can see that really is. The ensemble members are about as vague as possible on anything in there. Pretty much incoherence. This is true in the GEFs and GEPs, too. What we have is a modest signal in the numerical telecons ( that just means the forecast' index states ... PNA, EPO ... etc). When the tele's indicate 'favorable' periods they can be more and less so; a clue to how much is in the magnitude of the deltas. In this case, this is a small +d(PNA) variant between the 28th-sh and the 3rd of Feb. Little bit of a longer read: It's on the front side .. or climbing PNA that parlays. But in general principle, any time an index enters a period of change, that's when events unfold. Some times, the event its self is beneath the numerical registry due to scale. I like to refer to those as sub-index events. A disruption in any mass field ( which is what a changing index indicates ) requires restoring of some sort, as/while the disturbance propagates its way through. This is how all weather occurs. But, it is happening at all scales. Some events will occur, but the governing perturbation in the field was so small that it was less distinguishable from noise. Example, an Alberta Clipper zips down the flow and stripes down a light snow event ... it eventually moves off the coast and escapes into the Atlantic. This type of event may not appear to be associated to index change of any kind, but the restoring was simply too small compared to the size of a index domain. They are the same "size" as the noise in the field. They are insufficiently large enough to move index. In fact, some of them can move down to the NJ coast, redevelop more robustly upon reaching the moisture/warmth of the Atlantic. These can develop fast enough to create winter impacts for the upper middle Atlantic and southern New England regions ... all of which took place with very little leading index changes. So, we are in wait still to see if more guidance/cycles therein start physically materializing a system there. The GFS had more so in prior runs to last night, but in these very recent runs it is kind of a garbage dying ...something. It seems the model's trying to rush the pattern change, which neg interferes. Probably bullshit... Then we range to the 00z op Euro which pretty much tried to double everyone's seasonal snow fall and then some to date, in a powerful coastal... GGEM, ... not considered a tie-break in this unknowable situation, has the SW ejected/opening trough entering the western OV on the 2nd, but has so much confluence it's hard to imagine that getting up here...

That matches the temp anomaly products that have routinely demoed warm air that morphs to the cold side only when it advects beneath 50 or so n. That’s been a recurring cinema. This pattern setting up in 1976 might have been more like cold at both ends

actually … PVD and BOS are both -1 right now.

This is like a “standard above normal” month … which after multi season acclimation must seem colder than normal.

GGEM did the best in mid range. persistently showing impacts while the other models were unilaterally opposed. The GFS did do well on one or two runs around D 4 or 5 but lost it.

shoulda put this over here There’s likely a pattern change after the GHD system. Not enough ens support at this time for a GH event, but the telecon numerics give some hope to winter enthusiasts. The higher res op versions led the way on this last event … but it was also n/stream driven. This next ordeal is a forced open transiently closed sw low that’s kicked down streamand acts quasi southern stream … different circumstance bearing no similarity. Afterward the extended signals the first real cold relaxation in several weeks - not talking about half day cutter warm intrusions … I mean the hemisphere synoptic scaffold. It may be a thaw or something else … there are conventional reasons that are in play that argue for an earlier winter exit. We’ll have to see what that looks like in 10 days to two weeks.

There’s likely some kind of pattern change after that GHD system …

tell them while this is happening, no less -

18z GFS signaling Groundhog Day again ... Only 11 days away, too, so very high confidence - Like all other systems this winter, this is modeled exactly the same - it's like we've been in the same pattern for 90 straight days. Very unusual... pattern gestation is typically 4 to 6 weeks. We've doubled that, marked just by the behavior of N/stream failing captures, and models still showing the same damn shit. It's basically because the ridge is too far west, so the flow east over the continent ends up too flat. in other words, needle thread as the southern piece out-paces.

Good thing we're finally losing the mashed up flow compression in the extended -

A remarkable adaptation of evolution ... only equaled by the advent of human deviance that happens upon the scene and decides to pack those preciously precarious protruding snout holes full of dog shit.

Low chance that Euro idea/bomb in GOM succeeds. That's a polar branch of the westerlies; one aspect that we cannot seem to shed is that whenever the polar branch flexes this season, the jet becomes overwhelmingly strong, and this stretches the wave lengths which then means the embedded wave spaces are moving fast. In principle, that thing's correction vector is thus pointed too late and speeding up. The only way to get that 'in time' would be retrograde the entire wave numbering...which I guess is plausible- just not likely. I'm more interested in the following aspect that is, for the time being, a Lakes cutter... but the antecedent environment is so cold ( and the GFS is very similar to this) both options end up snow to mix to drizzle with implications for triple point/dammed up the hilt. This follow-up wave is more born of a quasi-subtropical jet field. In fact, this has been bugging me ... I've been suspecting for a long while actually that there's a broad sweeping misconception going on out amid the ambit of Meteorology/planetary observing. There's a lot of notion out there that subtropical jets haven't been very well observed... I've been seeing them as just being displaced N of what previous generations were used to observing. If one looks beneath the curled up system out there over the 2nd (Euro), beneath that jet the only thing separating it from the Equator are 590 dm ridge nodal medium of general 582 heights. That strikes me as a laitude advance HC expression... I've read that the expanding HC was theorized as more of summer season aspect ( relative to hemisphere), but I don't think that's as true any more. The other aspect is, if we convert the geographic expanse into mechanics, the loss of HC expansion in the winter - I hypothesis - can be physically shown to be conserved in/as the observed faster hemispheres. SO, a trade off: we either have expanded HC, or ... if the HC isn't allowed to be expanded, the hemisphere speeds up as a conversion. But I'm sure most stopped reading this paragraph long ago... ha

Here's the heat burst just coming into the outer range of the guidance -

12z oper. GFS and to some non-zero degree, so does the CMC, trying to activate matters during that 28th-2nd time period. It's not a robust signal, but there is a modest +d(PNA) heading into the period, while still non-exhaustive cold lingers. Something for winter enthusiasts to keep and eye on. I mentioned a couple few days ago that was our next 'suggestion' for an active period. The signal hasn't really improved or decayed - 'tie goes to the runner'