Typhoon Tip

Right on.. You know, I was amusing to self that this may go through a curve of attenuation followed by a kick back. We lose 30% ...owing to that correction shit, then your bold aspect kicks in and we get maybe half what we lost back. Warming to Advisory to very low end warning lol

Yeah, I don't know about the 10th-12th ( probably does bias on the front side of those days given to the fast footed pattern...). There is narrow window in the larger mass fields to have that happen, but its closing. By the 12th, the -NAO block is already retrograding to D. Straight, which back exerts a shit ton signal for NW flow into Ontario ( mid/u/a ), which would impose obviously confluence/implicity higher surface pressure. The NAO is notoriously poorly handled. Even in the better modeled behavior patterns there are nuance headaches. Also, that event may become victim to system attenuation as it nears. A weaker system would end up along a more southerly route. And you can't think in absolutes - it's not a matter of Detroit versus Worcester. But even a idiosyncratically weaker total wave space ( due to model correcting in shorter terms) moving into an initially colder environment ends up more triple point. Just some thoughts on that particular event... It's very early.

I'm a bit leery that these 'weaker' profile depictions overnight might be real and/as part of that attenuation business I was discussing in the thread opener. Not certain of it ... just leery. I will say that I agree - this thing caps out at moderate. That much is systemic, anyway I'm also noticing that there is an innocuous S/W that has gained subtle strength hot on the heels of the Jan 7 wave space; it may also be introducing some negative interference.

Looks like 1-3” Rt 2 to Pike, 3-5” along the Pike and 5-8” S of there on that run. Quick mover.

It's bit theoretical but a deterministic problem with this 7th system is that it is at the far east end of the R-wave signal. That's like the flop end of a hose - metaphor obviously. This system reaches the greatest constructive interference depth actually back around 100W and is attenuating in the deep layer, buuuut ...it doesn't encounter the baroclinic instability/'gun powder' atmosphere until it reaches the EC.. It's not in ideal phase wrt to the super synoptic wave signature. Systems that collocate these two aspects, greatest feed-back with developmental cross-sections are actually comparatively easy to call. I know it's hard to believe after the last 5 years but we've actually had those on the EC before - easier calls from 6 days out actually can happen. Because this is developing at the attenuating end it doesn't have the surrounding mass field to anchor it from "feeling" tug and pulls from surrounding perturbation in the flow. You get these run to run shot gun tracks. Just to re-iterate ... the main difference between all these solutions really hasn't been in the magnitude of the system. They're all middling Nor'easterns with perhaps moderate impact ... the problem is where precisely.

It's this recent -EPO ... slated to go positive, but as I was discussing above ... newly projected to go back negative by mid month. I've noticed this in the past - pretty sure we've discussed it as a group. It's better not to lock in a teleconnector mode and have it become static, but to have them oscillate? We're spitting -EPOs over a 7 to 10 day periodicity or something like that and it's giving the middle continental latitudes a steady diet of unbalanced baroclinicity. That's basically a storm petridish. I think having the EPS' NAO over the western limb as opposed to the GEFs, which looks more neutral/E is significant because so long as the NAO doesn't become too weighty and thus suppressive for its own rights ... Basically that's how we turn a -PNA into the stormy index mode that this recent +PNA failed like the Patriot's season to do.

We will .. I mean D6+ is far enough ahead that it's probably more academic that there are disagreements. I'll tell ya, ... if you compare the Euro to the GFS (this 12z run) the differences are almost entirely spatial. The actual mechanics are not really sufficiently different enough to imply a different result based on that alone, but the GFS has it's 500 mb trough structure approaching the lower M/A whereas the Euro's is approaching the upper M/A. That's really the difference here. The GFS does have a weaker surface response to all this by some, but ... say it were N like the Euro, it would carry at least a pedestrian albeit regional snowfall across the area. This 12z guidance suite appears to be more about "where" ... less so about "if" a system will be on the charts.

yeah, I'm just trying to show that the Pacific signal has recently begun to change toward helping our cause with that. But it'll be mid month... I mean we might have to deal with 3 or 4 days of AN ... it's part of the business. But the lease looks a lot shorter at the moment.

I started to a thread for this system - fyi ... I want to take a moment to discuss a major overhaul to the hemisphere beginning to emerge. It was a distant typically 'iffy' signal before, but around 3 days ago it started accelerating into coherence. Now we are seeing -1 to as deep as -2 SD WPO anomalies emerging in the telecon projection. This is also happening nearly in tandem with an emerging tendency to 'sag' the EPO back negative. You might recall ... I recently was concerned for a major warm up heading into mid month, possibly compensated by a -AO/-NAO. The -PNA/+EPO signal ( previous) is a Pacific warm signal that was diametric to a cold polar domain exertion. Very interesting... However, now the Pacific appears to be collapsing the other way - new but real. A newly defining -d(WPO) --> -EPO sends the Pacific arc into the 'AB' phase. The expectation therefrom materializes ( or tends to ...) blocking N overriding colder heights uncutting. This also tends to raise heights over the Alaskan sector ... all prelude to +PNA. That sequence of events is the natural propagation of the R-wave distribution. It was all missing up until 3 days ago but here we are with what really looks like a wholesale change. The -WPO crash in the telecon forecast during the ides of the month, and what is interesting is that the EPO starts actually sagging prior to any transmittance of that WPO signal into the N-NE Pac mode. That's flagging a constructive interference being position in wait. The two of those together is interesting after the 15th of the month

agreed very much. I saw that 12z GFS solution and was like ya whatever. With all the background knowledge we have wrt to how that model behaves with longitudinal trajectories at this range. How often are marching back NW with that model moving from D7 to D3 ? etc etc. There are reasons to be leery of a flatter solution happening - which can be compensated for more power in situ to the S/W itself. This Euro solution may be opting for that. But in either case, 'where' it exits the ECoast, I don't see any reason the GFS solution has to be more likely.

Yeah, I'm not too worried about the GFS southerly whiff - that's not a-typical considering that model's heredity. I'm just more concerned about keeping expectations in check. I think there's a real system here ( duh ) but there are very really arguments to keeping it middling in nature.

If the GGEM and GFS' respective handling of the NAO domain are more correct, there is no 10th event for this region of the country worthy of much discussion. I don't see how that system can survive to unfold a colder result with a -PNA and an NAO that has gone and done what most do - pull the rug out from under needing it to actually be real. There is a -NAO there ...but it's gone toward the eastern limb which cannot work in the R-w signal where the PNA is negative. Can it change back? absolutely...

If your interested .. I outlined some of the reasons (theoretical) for why that may be the case over in the thread I just put up.

(GGEM + GFS)/2

Correct, buuuut, as I also *(tried at least ) to point out, there are ways to offset why. Those limiting constraints I discussed are very real ... However, so is the uncertainty as to what truly gets communicated out of the Pacific. If it is very strong ... some of it will be absorbed but there'll be enough left to cause problems/get an event out of it. Assimilation tech is not the same as it was 20 years ago? Back then it was more gappy. I mean, we used to have this kind of cushion of 'still can happen' relief, because the system in question would be out near the Date Line. The population of the model initializations of the time were largely interpolated and/or supplemented by satellite soundings that were perhaps more primitive than now. The last time a system relayed off the Pacific and abruptly re-appeared on the guidance after having faded was the Boxing Day storm back in 2010 ( I believe it was..). That one appeared suspiciously like it was 'lost then found' It seems those gaps have been filled in recent times. I've noticed better performance/less morphology in handling system/storm depictions post relays etc.. Still, with the flow being fast, I suspect this re-introduces some error proneness.

First and foremost ... Happy New Years everyone. Significant impacts farther N into central or even northern New England cannot obviously be ruled out at 6+ days, but at this time ( and given the conceptual points below) a NE PA through SE NE and southern New England are implicated the most. I feel pretty strongly that these systems ( and there are really 3 in the pipe-line; 7, ~11th and ~15th) are all likely to attenuate some as these date ranges subsequently near. The reason for this is two fold, both a bit theoretical - but do offer a solid plausible basis for limiting their realized significance toward something lower than the 'magnificence' of their D10 model entertainment. The first is related to model handling of velocity saturation, a circumstance that's been reproducible during recent winters . This has been both anecdotally observed over recent years, discussed by yours truly and any others amid the 'forumsphere.' But recently at least tacitly corroborated by publications, such as Nov 30 2023, "Fast upper level jet stream winds get even faster under climate change," found in the Nature Climate Change periodical. (just one example; I'm not aware of any other formal science) Why this is prudent? Models tend consummately toward too much amplitude in the D6+ range, ... gradually losing some percentage as handled embedded wave spaces near and pass through the abruptly improving performance window around D4..5 lead. The reason for this, I believe, is because as the models are correcting the flow faster - in keeping with the above, the +d(v) outside the local wave space, robs from said wave mechanics. It's speculation on why that amplitude bias ( and there's other plausible arguments related to chaos logistics..etc..) is apparently endemic to the technology in general. I see this occurring in all guidance sources. This is a candidate scenario to express this phenomenon, and if we rob some mechanics from the S/W itself ( think 'velocity absorption') it will tend to pancake the latitude of the disturbance envelope, converting the system into more of a 'needle threader' scenario. (these are tendencies, not absolutes). This can also be compensated by the S/W being sufficiently powerful enough to offset that taxation ( heh, being rich enough). The second of the reasons, the teleconnector spread is not very supportive of mid latitude amplification east of 100W across the continent and hasn't been for long while in the projections that are based from all three ens clusters. The PNA is in fact entering negative delta during this week, and ends up negative spanning week 2. The fact that we are also attempting to eject troughs east across the continent means that the larger Rossby wave function is in destructive interference. If you loop the ens mean 500 mb g-pot anomaly products, this is likely why there is a repeating pattern during these recent days of guidance to increasingly flatten/open up the waves as they come east in the cinema. Summary: This is as of now logic. -- Should the back ground telecon change -- Should the Pacific relay enough S/W mechanical power to offset the inevitable speeding up the circulation canvas. T Of these two offsets, the 2nd one is more likely to be realized. *It should be noted that the governing mechanics for the Jan 7 event are still out over the N Pac. Graphics to help elucidate this are welcome ... I'll probably be contributing some but wanted to get this thread started. For now I suspect a middling event "precipitates" (heh) out of the total pros and cons with this Jan 7 system. I suspect that the 12z GFS may correct N ... unless it has some special handling out over the open Pacific that makes no interpretive model analysis ever necessary again ( ), which is less likely to be the case. But I'm not sure of the GGEM type intensity.. It's more likely to modulate down based on the constraints discussed above. But we'll see. There are two ways to limit impacts IYBY: Size and latitude of storm.

It’s too early to be specific, of course, but just for fun… The Canadian solution underscore what I was saying early about the sneaky wind potential. There could be like a 2 to 3 hour period there east of Worcester over coastal southern New England where they get battered pretty good with wind gusts and sideways snow in that solution

Meant to respond a Tauntin’ ha ha ha

You guys seem to respond to whatever image you’re seeing with no larger perspective. Weird It’s an encouraging GFS run for obvious trend potential/reasons

That’s not the take away… The take away is that it’s in flux man.

Huge changes in the total synoptic handily across the continent with regard to the 10th on this GFS run

Previous run was better by 10% or something

This may have a sneaky wind issue for the Massachusetts coast and along the Long Island sound. There’s just enough pressure well there and up against that high-pressure over Quebec …there’s gonna be a decent gradient there.

Anchoring high pressure like that is something we haven’t seen in years.

Interesting … seemed to start out that way but ended up the same