Typhoon Tip

I’m not sure why … and I’m not saying things are gonna work out this way, but for some reason all evening, I knew these model runs were gonna look this way tonight. Don’t ask me how I knew I just had a feeling like I didn’t wanna even look. I guess it’s good for the mid Atlantic snow for at least one of them.

Certainly, the models are having trouble with it cause there’s continuity problems everywhere. It’s like we’re threading the needle in a lot of ways even though the systems are a little bigger than that. When the streams are so fast and energetic, little variances just have a disproportionately large consequence Like Scott was kind of hinting

Doubt it - the fast nature of the flow is just killing this entire period. It’s a looming negative factor and every time the model run seem to conserve more of that ridiculous speed problem we get solutions that are whiffy and stretched out like this and I’m not sure it’s not true. We’ll see.

GGEM gone too. Think we’re seeing a consensus emerge proving the GFS was more right. Big bomb misses us.

Trough coming a teeny smidge sharper faster tho so again, not enough time

Well ... it is what it is. The -AO/-NAO appears to be exerting since ... Will it continue to exert? hm I'll tell you one thing: all three ens sources have the EPO negative through the 5th before it starts rising. It seems the lag of cold loading down to 40 N it "might" have a feed back on helping things because if it's cold S/W of a NAO block that would actually help lower the heights over SE Canada to the 50/50 low. Transitively ... that enhances confluence and you end up with a surface high ... I think we're seeing that in these GFS renditions - whether this all goes down this way? we'll see.

Ha ha... it is. It is just unfortunate for storm enthusiasts that it's on a D10 chart and not on a D2 chart. I'll tell you ... not sure what your origin/age are but in 1997, Dec 23, one of the most spectacular ( unforecasted too!) choke snow falls unleashed shock and awe out of an isentropic explosion that drove people to do what you just did ...ask if it were even physically possible. This fuckin thing dumped 23" of snow in 8 hours in N Worcester and Middlesex Co of interior eastern MA, where was forecast' 1-3" with as much as 5" in the elevations of wet snow. The temperature never got above 30 ... in fact, I was living in Acton Ma at the time and know it never got about 27. Straight down snow so heavy that you literally could not see more than several feet outside your window, fell for 4 hrs, shouldered on either side by 1 hour of 1/8th to 1/4 mi vis. I measured a one hr 7.5" in that. We ended up at just shy of 18". Those kind of exotic "synergy" events do set up but they are by virtue of what that implies, extraordinarily rare. Rarer still would be any GFS model run actually setting one up on a D10 chart and actually verifying. lol

Wow... that 10th-12th deal is something we haven't seen in years really ... a full on multi-faceted continental mauler. Tornado testicles along the Gulf coast with that jet structure fanning over a Gulf LLJ like that... Meanwhile, that high pressure and damming is not going to lose with that back built structure in Quebec - regardless of what the GFS thinks is happening with the set up, IT WILL BE WRONG if attempts to win with warm air N of the PHL with that look - and that's generous. Meanwhile, there's bent back trowal blizzard raging (probably) fo chi town. what a mess. Like the model is over amped at this range but it's nice to finally get you guys drug delivery. Just don't let your eyes roll back in your heads and your eyes turn opaque lol

It's the western limb of the NAO crashing doing that - I'm certain of it. The system isn't going W of DET - or having difficulty doing so with exertion back transmitting through the field. How the f can it? thing of the eddy structure - the whole flow at mid levels becomes a barrier jet.

Obviously there's lower preference for the GEPs/members but ... seein' as you were discussing "ensemble means" and suspecting phasing... the GEPs DEFINITELY have members. One of which takes a 967 mb low along the Jersey coast to 961 just S of ACK, in a field of sub 982 members in that region of enhanced spread. Those members doing that are likely all N/stream consumers. This is doing so at 126 to 144 hours - that's not a terribly long lead. Not sure we should discount that entire ensemble system entirely here. I also want to point out (lower probability for positive return but non-zero nonetheless), both pieces to the 4-6th puzzle are not being sampled in the physically realized sounding grid yet. It matters a lot less now with assimilation advances. However, we've already seen one system last month jump in amplitude by a small measure when it came on board back in November. If there is any pattern foot that would seem more likely to express that sort of correction ... fast and therefore error prone might be one of those.

Re the 4-6th ... I've always been leaning in favor of this event over the latter 6-8th. The reason is just to do with wave spacing in a higher speed rate pattern. It's tough to get even two middling events just 36 hours apart. When in this forecasting dilemma in the past ... personal experience, the lead tends to win. Having said that...there are examples of that in history (succeeding) Dec 1996 leaps to mind. That double dong I consider to be the same event because we finished up a 4-6" tree clinger, settled off to 30F for still-air sagging tree and powerline retention, with no clearing inbetween. The 2nd came along the following night with 9-15" and thunder snow. It can happen, but the rarity of it - more typically ... the models will start keying in on one or the other and sort of sacrifice the other's wave spacing and/or dynamics ( moisture/instability parameters). I like the 12z GEPs ensemble mean the best just for eye candy. Down near 994 at 132+ hours lead, with a lot of spread pointing to the NY Bite, while there is sufficient cold back loaded over land ...this is a tasty optic. Almost ominous. It's in the upper 20s in the 2-m while this correction vector is pointing toward a strengthening nor-easter. (not a forecast - just a muse for now)

I like the fact that it's positioning over the western limb of the NAO domain. An east biased blocking would allow more room for the dreaded Iowa to western Ontario storm track.. but, when it is west, the "Great Lakes squeezer" low enters the picture. With confluence barrier we turn a -PNA into a winter storm index.

I'd like to see them deeper than 999 mb but like Will said ... it's still close to 9 days out.

Heh I've noticed that many times in the past, too. These guidance et al seem to exhibit a kind of oscillation between amplitude and positioning. Less or more on 12z, and vice versa on 0. I wonder why that is... I used to think it was diurnal load balancing with hemispheric heating on day vs night side but that seems like it should be less evident in winter. I don't know -

I wouldn't trust the op Euro beyond 5 in this pattern. You have a high speed -PNA under a 'tendency' to back drill colder heights into SE Canada from a -NAO that it also agrees will set in, so what does it do? Stalls a planetary trough node over Nebraska and carves heights down to Texas. Given that model's heredity of lagging heights S/W (is it really over that obsession?) ... it's like trusting a con just because they put in their time, but now have been released out into the temptations of society

To reiterate my own position on January stated prior to Xmas, I didn't really have a strong confidence for anything beyond the first 10 days, but at the time ... I was leaning warm. Since then, however, the -AO/-NAO seem to have gathered momentum in the projections. We'll need to be cognizant of that. If yours and other's sentiments re a "switch" were to take place, it's also possible these -AO/-NAO indicators are like a zygote to that pattern in the making? Just a supposition - not a forecast there... I gotta say...if these latter polar sources back off and/or fail exertion, yeah ... I don't have a problem with a mid month warm up, because the Pacific is raging in a AA phased (-pna/+epo) import which correlates to a Chinooky continent.

Yeah I do too, just so these systems have a moisture source. That's not being a wise-ass, really... I just with the fast flow these friggin bottle rocket N/stream S/W enter the Pac N/W continent and exit NE in under 72 hours, they don't have 'time' ( for lack of better word) to operate. Having an ample moisture source inject helps that.

GEFs trended in the z-coordinate depth under LI for the 5th, though. Not a lot, but those several DMs should be construed as a lean toward more amplitude considering other guidance are trying to weight a consensus that way... Simply put, don't give up just because the scalar depiction is a miss. Also, the run to run comparison of the GFS shows more cyclonic orientation to the surface isobaric layout, with at least as others mentioned, more 'snow in air' Maybe it isn't too late in technological evolution to still get a Boxing Day correction... Also, having looked over the general tapestry of this run ... yeah, it's pretty clearly reconstructed around more -NAO backward exertion through the field. Can't recall who mentioned it ...but yeah, this is more likely evincing through the coherency improvement with that 50/50 spv

Not to NARCAN the moment buuuut, the teleconnector correlations during that time rapidly reposition over Iowa for that 11th system. Being D11-13 in the guidance, I don't have any qualms with assuming this run is doing save vestigial GFS tenedencies toward progression bias. We'll see. I'm not trying to ruin your high here, just to maybe establish a (sure to fail -) tether hold on objective con. Having said all that - there is also a -AO/-NAO aspects that are fu'n with me. I mentioned that these other large scale suggestions could in fact cause a polar boundary to fixate along the ORD-Logan type latitude. So ...in fairness, this run could also be responding to these latter index mode forcing suggestions, just the same

I realize your tuggin' winter enthusiast pubes with this statement and it's all fun and all. Just the same, I saw geese in V formation communicating overhead in the midst of that 2017 March Nor'easter, not 10 minutes after there were two lightning flashes and the reporting thunder ... At the time it was S borderline S+ vis in the 1/3 mi range. 31 F I was like, 'whaaaa -' I'm able to recall all that because in the moment it was just too weird - like one of those 'where were you when -' moments. Seeing them fly over, apparently they absolutely couldn't miss their flight so they had to risk it ?

Probably of less use to most but that ICON model was a stem winder with a burst of strong NNE flow in moderate snow for eastern MA, with a blizzard condition likely evolving up in Maine east of the cordillera up that way.

That’s some kind of a freak event in the Plains in that depiction

When did Logan have .2?

Model performance hasn't been stellar the last several weeks really. Lot of false leads that smeared into oblivion. It's not really 'expected' that models perform well with entities that emerge beyond D7 but even relative to that expectation ... this has been a bad month. Having said that, the 1/5 system ... yes I did mention last week that would be 'probably' the higher likeliness. Since then, what you are observing is that poor handling where aspects seem to disappear and re-appear head-game. There's been large scaled indicators that pointed in general to Dec 28 thru Jan 8..10. So we're moving through the period of interesting now with ho-hum model continuity with these particular dates. Short answer yes around 1/5. But 1/7...1/8 is still in play. My hunch is that 1/5 or the latter will become dominant over the next 2 or 3 days of modeling, but not both. There is a slim chance they'll both disappear altogether.

Noticeably more aggressive diving the N/stream out of Ontario though - that's allllmost ominous. The problem (the way I see things...) is that the total trough space, inside of which the N/stream and S/stream are flirting with having integration, is progressive and doing so too fast. They ultimately do phase, but the playground itself has move away from our area before it means much here. This is actually a hemispheric problem, too. Every thing on that chart is bodily moving unusually fast down stream. I'm not sure if this can modulate better ... I mean it's 7 days away. But even 6 hours slower and a slightly fast N/stream plunge is pretty much all that would take to clip the coast from NYC-PWM with the season's first