Typhoon Tip

The PNA being neutral with an - in process - negatively escaping NAO ( ends up +1 and change by D7!) ...is pretty damn indicative of a longitudinally 'stretched' field and the GFS ..too much? Here's the problem with determinism in summary ( from me ): 1 ... the GFS has a W-E bias as a base-line model problem ...and in a pattern that is in fact, biased in that regard ... that, for lack of better word might be "enabling" the GFS - and it's thus too much. I suspect it is over doing the west east latitude bottling of this system; which it could still be right if the next 18 or so hours relay paltry momentum off the Pac... 2 ... the sensitivity for this particular system appears to be mainly in situ to the S/W mechanics, itself... Assuming that we are not ( and it seems likely we won't at this time ) be getting much positive/constructive larger scaled pattern feed back, due to the flat PNAP structure of the flow...that leaves the S/W itself. If it comes in stronger...it will roll-out S/W ridging in nuanced quantities...but that would transitively mean a N totality of events in that case. The confluence and attending high are presently holding proxy on the depiction from the GFS but ...meaningless if the GFS native W-E bias happens to not see the real strength of the wave mechanics because of ... improficient assimilation - I've been saying all along, this entire scenario is unusually susceptible to subtle and nuanced variance... 3 to 5 kts in the wind core could mean a lot .. The other aspect, on #2 abv... I am noticing that the 500 mb wind max is actually coming of in a lag feed - it's not coming into the west like a slug... Such that we started pulling the wind momentum into the grids on the 18z ( where available...) but you look closely...the full/total momentum of the wave isn't fully absorbed until 12z tomorrow... As this relays in that time, cycles "might" alter. ... Anyway, I think

Yup ... coastal storms

18z GFS boob range unloads that interior NW territory crying hell and drills it at us

Code for ‘... ignore the piece of shitness in lieu of our dazzling parameterization’

So... some "lensing" and usage filtration going on ...lol - ... late to the morning party. I wonder if anyone's posted the least snow fall total map presently offered regarding this event ...doing so with the same zeal and attitude of joy - ...yeah right. Lol I was not personally impressed by the 00z suite in the handling of the Atlantic total pattern ... It's almost more in the 'complexion' of it - its hard to pick a discrete feature to demo this but it just sort of reverted by "attitude" toward a faster look ?? The 50/50 appears in the 00z Euro still, but it seem to be like... 4 deg of latitude more progressive so..noise? perhaps.. .but, I the idea here was that the 'noise' should sound like going the other direction. And I don't see a lot of -NAO migration in the 00z suite regardless of model camp, either. It seems yesterday's panache in that regard was not carried over so much into the 00z run - ... Fwiw, the 00z GEFs tele did also back off the -AO heading later in the week, and the NAO is technically positive albeit nearly neutral, along it's prognostic curve...so, again - we pick and chose the products we use at own risk I suppose... Be that as it may, ...the system for late Wednesday doesn't necessarily have to have a slowing/back-log exertion from the a retrograde Atl tendency... To reiterate last night .. if the PNA --> PNAP nuance a better post ridge bulge in the west, than it can amp and slow a little form the opposing direction...etc.. Regardless of these plausible modulators ...it's middling impact fast mover. I see it coming in like a wall 10 pm CT to 1am ASH and leaving by 10 to 12Z CT and mid morning up this way... It's like middle ground needle threading - there's some interpretation variance on what "needle threading" means ( apparently ..). It's subjective anyway... but to me, it has always meant narrow latitude of impact, ...not really much else. But usually, in fast flows... because the 'narrowing' and 'why' the flow is fast tend to be rooted in the same biases. Such that 20 miles on the N edge of storm output means you're on the in or the out. Dim sun to substantive accumulations over a short distance. So on a mid range chart, you're looking at a rifle shot at 400 m and trying to hit your city, through the threads of your sight-scope. . pilin' on metaphors... Storms that slow down get more 'circular' in geometrical circumvallate and that's why they are "bigger"... I see this as having some of that needling, but sort of bigger hybrid version ... It is a fast mover - and it is moving through some compression in the heights... I don't see much evidence of "slowing down" - not sure where people are seeing that in any operational model.

Cautionary noted: one needs to consider climate change unfortunately... The ambient Terran troposphere holds more water vapor at a given temperature than it did in 1930-1931. Even at decimals ..this has a tendency to "synergistically" result in higher individual deposition extremes...but also, maintenance precipitation events are also routinely delivery more in recent modernity. This is/was both modeled by climate prognostic efforts, and is also empirical/verifying. Having said that, that doesn't/won't/shouldn't be accountable in a particular anomaly at PHL, no .. .there could certainlyresult 13" of snow in a La Nina ... regardless of era. But, the likeliness of it happening now given sufficient cold at/while other analog values, is greater due to increasing ambient moisture in situ to atmospheric events.

My guess is the GFS isn’t representing the slowing Atl pattern pretty much at all

Monday thermal layout hasn’t really looked conducive … marginal tho This is almost bulging back north as a pseudo- ANA and cold advection hasn’t really had time to get in

Well regardless of whatever happens with ptype ... that is a beautiful rotation of that 500 mill bar structure/correction

Almost an indictment of its BL resolution one wonders. With a high in a position like that there’s going to be a barrier jet from Penobscot Maine clear to Trenton New Jersey and there’s nothing that’s going to get through that axis sorry

Yeah I wasn’t looking at the deep layer Brian I’m just noticing the surface position of the high - it’s not moving off it’s perch north of Maine quickly enough to believe that CAD can be eroded that quickly that’s not really sensible in physical science or a climate sense

It’s in speed heaven for the past 7 .. 10 years. Lol. It’s too stoned to notice Monday’s memo.

Yeah no that’s next to geophysicallly impossible ... Not sure if it’s a simple as just making the QPF loaded colder or lowering the QPF to atone for the cold but either way ...no way it could be that warm with a high positioned like that physically impossible it’s a bad model solution

Icon is most likely over doing now but that mid week system probably about 20 to 30 inches of snow

NAM bumping Mon NW may be the beginnings of phasing/interaction ... heading into the 50/50 destination

yet... all this predicated on the assumption the Pacific is sampling sufficiently to keep the 'wiggles' in check - but ...this thing Monday's nearing the coast and all the sudden? Given the antecedent and carrying on with it, fast flat high error prone flow ...determinism is at a premium. Think the general idea of Monday phasing and 50/50 the hell outta NF is probably heading in the right direction - too much multi-modal NAO support and it fits that paradigm really ... If there's ever a chance for the f'n bevy of guidance to get one of these damn NAO's right ...this would appear to be the best likely candidate time - That being the case ... the mid week approaching the MA I think gets some modulation - ...hmmm stroke goatees

this thread is/was intended for the mid/late week system but ... this is complicated and the foreground antics in the flow are involved with what transitively sets up downstream...which ( phew ) in turn modulates on the timing and placement of key evolving components for the latter system - so...the thread encapsulates the whole damn thing - Summary: Monday system may phase and stall into a 50/50 scenario - that would slow and probably back amplify the flow into the MA for the 16th.. or - Monday scoots out ..phases misses.. .and the 16th may rely upon western ridging (correcting...) and needle thread timing a potent S/W ... or - something in between ... But I don't know if we can really disconnect all this shit and do the whole thing justice - ...

It's like a tri-pole signature to look for - haha, call it the "junk" configuration

ANA's take place ...they are real - but ...I have come to find over the years that a larger number of those scenarios modeled, tend to actually evolve into more proper cyclone features with typical NW arcs/CCB headed frameworks .. It's like in order for A ( no system ) to get to C ( more significant system...) ...the model passes through a couple cycles of ANA B ?? That said, I'm really less intrigued about Monday as an impact here in the upper MA/NE region...and more so for how it helps in modulating the total synopsis for mid/late week - I do think that it is interesting that it is "more involved" in that regard as it is coming over land though... Anyway, 50/50 seed

That's how you know big storms loom on the horizon ... com's problems - I think some annoyed student even did a correlation study up at UML back in the day and found ...something like a .71 correlation coefficients between bombogen cyclones and f'ed up model transmissions, corrupted data or nothing sent at all to DIFAX. back whence that was pretty much all we had - internet was too new.

I just wrote about all that above ... in short - ... the recent guidance ( save the GFS which I'm okay with given that particular guidance's bias' ) is phasing it with N/stream and really going crazy with deep anomaly over the lower Maritimes ... we call that a 50/50 when that does that... Yes, and that 50/50 is "plausibly" anchoring due to overarching -NAO tendencies.. But the depth of that 50/50 is unusually deep in the Euro and actually the GGEM ain't much shallower ... And that sort of in total is the same differentials.. weird - but ... that is a 'backlog' that can slow things down. The Euro could be too deep - it has it's own bias to over z-coordinate matters in that range too - but that is a climo spot for maturation of cyclones so ...heh It's a precarious thing... My previous lack of enthusiasm for those paying attention, was really owing to conserving the persistence/fast flow ... But given reasons to offset? Sure...I have no problem discussing now. Again, this is higher uncertainty too -

Edit ...I left the GFS out but should have mentioned - I just don't think the GFS is going to handle the 'blocking' or -NAO/-AO exertion leaving N/A due to it's discerned velocity bias - it's not the tool for that gig.. I won't bring Fender electric guitar and amp to audition for a violin quartet

This is a problematic assessment due to inherent temporal-spatial uncertainty typically found with these kind of anomalously fast, flat flows coming off the Pacific over the North American continent. We are endowed with neutral PNA ...tho hinting at rise, while relaying into rather uncertain PNAP and whether that will feature western continental height ridge distribution, while the whole of that flow appears to 'train wreck' should these Atlantic signals continue to emerge. The short version: there are presently three distinct events possible in an 8-10 day span: Monday ... Wednesday ... over next Weekend - the usual caveat emptors apply, but are enhanced by said limitations... one must be open to the notion that given said limitations any one or all three of these are subjected to change, more so than normal for this kind of threat assessment at < 10 day leads. Case in point: More detailed: Monday's wave space is just beginning to tickle the denser, more physical soundings out west... I do not ( personally ...) believe that it's sudden emergence as a mere quick hitting, low totals but plausible higher impact scenario is a coincidence ( the assimilation tech is impressive and satellite sounding are hugely useful and needed, this is not a knock..) This feature's been identifiable in the stream for a few days/cycles but, we are in a low tolerance/precision mode, where nuances take proxy on determinism ...and subtle almost unobserved variances run to run can mean nothing of or grid locking commutes by cold and flashing on streets... This system may become crucial later on ... The Euro and GGEM phase it with Canadian/N/stream rather uniquely and barring a Euro flub- up at a mere 4.5 days in advance ( which despite any popular street cred, that model is typically still good in that time range - yes it is... stop it...), that union is destined to drill an anchored hole in the cosmos in the 50/50 location as shown in the Euro example further below... Then, the picture gets more complex because there is now better evidence that blocking in the northern Atlantic may be real - the stochastic nature of the NAO in the guidance ... it's the least predictable/dependable index domain spaces I know of, where predictions for winters can only be made the following spring but here... we have multi-day/multi-ensemble derivatives with more -NAO than the operational complexions that until very recently were not as prevalent in operational run ... With that onset, getting harder to ignore for me. That latter aspect is crucial ... heading into the Wednesday time span. As Will has bothered to put this quick annotation together ( I very much agree - so have poached it from the other thread ... ) this Euro depiction shows how a transitive "back-logging" of features across the downstream circulation ..can have an effect on pattern morphology and systems embedded as early as succeed 100W longitude coming east of the Rockies... Namely, the MV/90 W wave over midriff CONUS, for now...the most important system of the three in question: But what also leaps out to me is the ridging in west is more pronounced than earlier guidance ...and I have been waiting on that piece ( personally..). It probably isn't absolutely necessary in the R-wave distribution ...since downstream blocking may factor - so less "perfect" idealized structure is needed between the E Pac and 70 W when/if the flow is force to buckle... but, having that emerge really makes this more acutely interesting for that mid week system. It's more +PNA relay and suddenly ...teleconnectors converge The PNA is showing a tendency to rise again next week, and with an on-going -AO and these deeper SPV migrating through the PV rampart latitudes... Don't let the flow slow down or watch out! This becomes a subsume phasing orgy all over the place. For now, we favor a stormy fast reload pattern ... and watch that retrograde of the AO/NAO... and if any western ends of SPV try to dip into these Pac waves... It's an odd overall look, to run a depressed AO index with a downward modulating NAO... and an uncertain PNA. For now, I favor ( regional relative ) low to moderate impact events in repeat strike loading ...2.5 day (~) turn over times... But, monitor that ridge spacing in the west, because if that gets a little more while that 50/50 trundles about, we end up with slower moving menace mid/late week on the EC - also out there as possibility...

It hasn't been readily observable for me because I was being a presumptive asshole ? lol - no seriously...what this is .. is the depth of these SPVs and '50/50's around the ring of the PV are exceptionally deep. By virtue of those ...it is making the index derivatives negative ...and typically, we don't see "ridge" at 534 dm ... But, the Euro has a 564 now up there over the eastern limb of the NAO and Will's pointed out that it may have been easterly bias -..though attempting to retrograde ...anyway, point is, the circumstance didn't leap out as very obvious - kind of an insidious -NAO if you will.. interesting. But, that 50/50 is exceptionally deep and I'm seeing enough evidence in the GEFs also - big fan of cross guidance method - that a 50/50 occurrence is likely real... and that's just as valid as Will pointed out. In fact, I just posted to him and Ray myself that I though the SPV depths were maybe "why" the AO was negative more so than going the other way with taller heights ... then it rears a factorable ugly head in this analysis an hour later. huh -

I'm about to fire up a thread for multi-event potential next week and would like to use your annotation above if you don't mind? I'm just gonna have to do it again otherwise -