Typhoon Tip

it’s conceivable that we’d get most of the snow this year over these next 10 days to 2 weeks

I’m not sure what I have to prove? I outlined plenty of uncertainty there

Fwiw I fired up a thread for this made a case for cooling the Euro future runs but we’ll see.

16 already DP 4 nice tick insecticide

This is intended to begin specific coverage for a 2-4 or 3-5" type event on the 6th, intending to leave the larger, more interesting coverage for the 9th/10th to a later time. This is actually fairly straight forward scenario. There's been remarkable stability in the recent GFS operational runs for active wave transport along the pattern-fixated polar boundary. Yes, that is likely to be a repeating theme for the next 10 days, but again ... not getting into those scenarios here. Short version: the higher odds for this, what I suspect will cap at a lower moderate mix and/or event, will likely involve areas N of Kevin ... Pretty much Pike to about mid VT/NH and lower Maine. I'm actually inclined, though reluctantly, to invite him to this party ... given to the arguments below. However, in deference to the N tracked models there's a compromise. Longer version: the GEFs mean is slowly inching toward the operational run, which is being pretty strictly guided for where it can move between the stolid S-SE ridge/compressed field, whilst the -EPO attribute/on-going cold loading is pinning the mean polar boundary just S of the N/stream jet into position roughly IND-PHL. This "should" ( famous word usage ) limit the wiggle room to between LI and the Del Marva. Below, we see the GEFs at 18z beginning to bite on this concept, with a clear indication for stressing the pressure field E along that path of evolving/lesser resistance. This is also a bump S and also incrementally more coherent than the 12z ...which was more so than the 00z last night...etc. I'm actually a bit more concerned in this general synopsis, for compression beginning to correct/ attenuate matters. There's that, and the fact that models tend erode 20 or so percent of amplitude off everything... However, in this case we are solidly < than 5 days. It's time for the model to put up or shut up. The GGEM and Euro carry the 6th as well, though obviously those vary toward a more N track and bring more of a brief icing after perhaps a shot of snow. Definitely within the possibility envelope. However, in both the EPS and GEFs derivatives the NAO index ( where in the hell have you been all season! ) is dropping precipitously from +1 now to about -1 SD ... Now, it's possible that the physical manifestation of the block is situated less ideally N in the D. Straight, however... this is still overall a western limbed orientation, so I suspect some limitation to a west/left turning track as a transitive influence - might be a correction coming from the Euro. Lastly, there's a bit of an intangible with this... The very fast bias in the total troposphere lags the surface drag behind, with cold not getting scoured "out" in time prior to the system moving off. If the coalesce to track along and S of LI fails to take place, and this does move west/left of our latitude (SNE), for the love lorn model/storm enthusiasts ... that will likely insure at least a start as snow and then a transition sequence. We don't have a shortage of cold air leading this event, either way

I think the 6th is good for a 3-5" type deal ... I may start a thread on that this evening - it's a nice pattern entrance kind of appetizer. I also suspect there's at least snow in the air from the waa pulse tomorrow night but should be low in significance. These are all nail biter needle threaders. I know what your saying about the sinking south with the SPV but I'm also a little of leery of some of these systems falling victim to negative interference thru compression. But we'll see. Hint teaser, part of my confidence is because the NAO is falling negative pretty convincingly, multi-sourced. The NAO doesn't cause these systems, no, but ... it's useful in estimating track configurations. In this case the correlation fading away from early left turners. So I see the eye of the needle as being between LI and the Del Marva, unless the total scaffolding changes

Folks 'ill be within frozen spit distance of 0 tomorrow morning. Probably a lot of 6's

'Magine if nothing happened ? ho man.

The 9th is actually attempting a Miller B in the EPS mean ... It's a rather unusual approach. Typically, that storm type originates from the N/ or hybrid stream coming down the polar boundary, whilst lower +PP is situated over or N of our region, but this mean at 12z is approaching from the WSW. I think I see it though. The jet is still a polar branch - it's just doing a weird circuitous journey through the continent. Also, there is modest +PP N of the region to help enhance baroclinicity but it's in the ambience more so than a nodal surface high pressure whatever too much effort for this range

Anywho ... nice to emerge for a change into Saturday morning's coffee and danish time, with such a cornucopia of delicious Meteorological aspects to run through the social media mill, huh

Iiiii'd still be leery of the height compression. That shit smearing from southern Cali to SE of the Maritime is real. It's an opposing force that is always there - never mind why You'd rather have the above look than no look...sure. haha. But, it would be nice if that field was more neutral in the means, kind of like on the opposite side of the hemisphere you see above. That, underneath that Hudson node, would be the superior product. Above is 70% of that

thanks for saying that ( bold ...) ... See, I've been trying to impress to a room full of crickets for ...years really, that the NAO is purely a non-linear wave distributed forcing downstream of the Pacific resolution. In other words, these latter aspect trigger the NAO's circulation modes. Not the other way around... It may not be as much of a misconception as it used to be - thru a decade or so ago it was like a NAO chatty-kathy doll between the 1994 popularizing of it's identity, and the years of tsunamis miss-allocation of it that still to this day isn't completely dead. But when rock star Met used to say the NAO retro will cause an expo... blah blah, what they really should have meant was, the Pacific is hiding it's storm production from the PNA, by non-linear forcing. LOL ...you know, totally clear to everyone - Anyway, this so-far modeled event, with the PV split, appears to be completely harmonically caused, but at large scales. We're just seeing what an exceptionally well-tuned multi-vocal range chorus sounds like when they hit the sweet tone -

Fwiw, the split in the PV is evidenced all the way down to the 500 mb in the recent EPS - similar in the GEFs recency as well...

I know ...I was joking about this yesterday but partially serious... it's difficult to call out an ice STORM in this compression/high velocity, low residence time flow type. These systems are not standing wave icing events in this flow. Some of them are done in 6 hours. Even at moderate ZR clip, you're just not accreting warning levels - There's a tendency - no shit, huh LOL - to next level all hyperbole at the bus stops of social media.

I think what we are seeing there is really an exotic EPO explosion... It's not connected to an antecedent, down welled stratosphere warm intrusion/wave breaking event. If so, one would have happened in early January. So that's fascinating. Lol, I get the feeling folks don't care to engage in the theoretical discussion as to what's enforcing things, rather just getting them to take place... SSW's aside, it doesn't matter how we get there - once there ...that's obviously got an enormous potential to influence the mid latitudes on both sides of the hemisphere with that mobius structure like that. I don't think I've ever - personally - seen that kind of symmetric geometry so clean, so deep, and so removing of noise ... interesting.

Straight up is gone negative in the index derivatives, post ~ the 10th. This is, by the way is not SSW related. I know you're not asking or commenting, but I am just side noting: it precedes any perception of a SSW ( much less whether any burst is actually propagating downward, which take 20 days min for the correlation to kick in.. So, when the posters in here inevitably start sharing the gifted insights of the X poster claims connecting the ensuing -AO to all that SSW stuff, please take those grandiosities with a degree of incredulity. This is no statement attempting to abase a -AO. We've seen countless excursions of the AO index over the years, both positive and negative, whence they circulation modes gets there via other means. I'm just tired of the relentless application of the SSW complexity from people that appear to not really understand how it's occurrence mechanically influences the hemisphere.

We may not need waiting until after mid month ... In fact, I'd almost suggest that more likely players are troika through the 14th, then it may go cold and quiescent there after for awhile, because I agree with the compression - it's more than a mere observation; it's a large scale negative interference product that will limit the intra-scale events from ever being able to amplify. That said, the three system - their success notwithstanding in this statement ... - that occur ~ the 6th, 9 or 10th, and the 13th-ish, are occurring prior to any such enhanced compression and therefore for more identity conserved - which leads to actual events succeeding in taking place.

I slept in this morning so bite it - that 06z GFS for the 9/10th was a mise-en-science of winter joy... It reminded me of that event in 2015, the one that came thru as more of a protracted WAA, with a series of waves along it, with arctic air entrenched on the N side. Something like 15" occurred here from that, and I don't thing surface pressure of any of those two waves on the front back then were less than 1000mb by very much. But is snowed moderate with some blowing and drifting for 18 hours straight - I'm about going half from memory here, half from artistry because I remember it happened more so than the details. Anyway, this 06z is about the only way to get a longer duration event out of compressed, velocity saturated flow type. It's also interesting that the 18, 00z runs leading were not hugely different. Last I checked, the op Euro was in another universe - Haven't seen any other guidance.

Unlikely its speed is guided by the character of the pattern foot … Im sure you’ve heard us speak of “compression”? That’s synonymous with fast bigger event on the 9th but seems suspiciously too amped given those same constraints

The models haven’t been completely giving up on the 6th and now the GFS 00z with a quick moving moderate event. This is < 6 days out there too

Roads went white as soon as it switched here about a half hr ago 32 S

Yeah been watching that for the last couple hours as it's unzipped east from southern ny/n pa... I'm wondering what that looks like when it moves over the 35 air along rt 2

Perfectly stated!

For now hold... but geesh! not impossible that we're seeing the local hemisphere through winter goggles. I'm guilty of it too. I mean I mentioned heat burst and recent seasons and -PNA and all that.. but, hammering consistency by these materialized charts gets a bit overbearing. Models are going to struggle with that boundary - that's a slam dunk for poor performance. Unfortunately ...about top shelf premium error magnitude exists across where ever that is

It's really not that much different than the going ideas, it's just about 200 mi or so further N with the front. The problem is, there's like 50 to 60 degrees of variance across the fugger ... That 312 hour frame could be nearing 75 in S Jersey, while Kevin blacks out and we don't get to see his posts anywhere ( oh no! ) from icing - This gradient thing is getting rather excessive, all necessary jokes aside - I mean, you wonder if this is even possible..