Typhoon Tip

Crazy negative NAO like ridge in the oper GFS though. Doesn't appear to help our cause but it is pressing the ceiling of the charts. wow. Approaching 600 dm in mid/late Dec? o kay

Yeah...I suppose being 200+ hours this thing oughta be watched. It's not mere noise in an errant operational run there. This thing has heredity going back days of runs - granted with the usual inconsistencies to be expected, the essence has persisted. Earlier I spoke of the +WPO/+EPO unfortunate motif that's recently evolved... however, the +PNA during the period between D6 -10 has also been there all along. The modality of which does send some correction signal/H.A. Obviously, this social media ilk of folk don't care too much for powerful WARM Miller A cyclones getting captured by the N/stream, only enough to slow it down while being too late to save Christmas nostalgia - understood... But should the synopsis over SE Canada morph in the right direction that profile could easily change

"those forecast" in deference to the above are a mean of all the ensemble members. They literally take the average of all the ensemble members. Each member has slightly differing physical equations, but they are not 'guess work'? I'm not sure precisely what you mean by "empirically derived equations" but ... the physical equations built into each do not produce impossible solutions. They wouldn't be of much use if that were the case. Each focuses in a specific aspect of atmospheric physics. There's probably documentation on each member's "genetics" ( if you will). Ho man - can you imagine the Asperger spectrum required to read that? Like Member 6 uses some experimental convective sequencing - now ... go and match all those days whence ever those were valid, and if those valid days match the circumstance at hand... weeee. Popsicle headache. Meanwhile member 7 ... some other variant, and on and so on. This stuff actually matters, because the thing about cloud creation (efficiency/proficiency: That releases latent heat during the pseudo adiabatic machinery of the storm, which if done by X physics may or may not be more correct than if done so by way X', or Y or whatever. The operational version's just employ what's worked the best in the past, through objective comparison with reality through experimentation. I may be butchering some of this but in principle that's the gist. Having said all that, the individual ensemble physical implementations don't change ( unless a wholesale new version is rolled out). They're just process out into the future based on whatever is given them. Which is the initialization provided by sounding/satellite

The following is a mash-up of climatology with personal anecdotal ( so tfwiw ) but pre-cold frontal: this system strikes me as not very much above mediocrity for W-N when considering the usual wind/mixing potential. The SE coastal plain/ Blue Hill, Cape Ann and up somewhere along coastal Maine - it'll depend on vertical mixing. I haven't delved into the soundings because I'm not getting paid and frankly the situation is uninteresting otherwise. But if you live in those area, you may hear it over the eaves, or even experience blinking or terminating lights - but comparing history? Nah. I've seen more vivid synoptic tapestry fail. I'm not sure this is an October 2017 (?) whenever that was Having said that ... I'd be more concerned along the (probable -) ribbon echo squall as it cyclically bows and wanes it's way E; as separate very brief wind burst concern, that'll be turbulent mixing. That could happen inland. What makes this system different than a straight up climate cold front, the kind that displaces windy mist/showery WCB that happens every so-often in Novie and Decs (sometimes January's too), is that there is a rapid developing Miller A along the boundary. That does introduce a bit of an unknown over the climate picture of standard warm wet wind end abruptly in squall ordeal at this time of year. There's a weird counter intuitive aspect - the Miller A deepening as it approaches actually offset the PGF in the other direction - or can. Depends on the d(p). This may lower the wind scouring inland during the WCB.

Do you think the +WPO/+EPO, beyond D10 .. ., is of the higher confidence, so high in fact that there is no realistic chance that things may break the other direction ??

Unfortunately ( well ... not for you but for the winter enthusiasts), the numerical teleconnection spread shuts down cold loading into North America, ~ after the 20th. This is also in conflict with the erstwhile consensus for wintry turn at the end of the month, interestingly. I've been keeping track ...about 3 or 4 days ago, the WPO projection flipped sign. As of last night, all the way up to +2SD. And then out around the 20th or so, the EPO goes positive mode. There is a lag correlation between the two, where preferentially ... the EPO will eventually modulate in favor of the WPO's sign - given time. So the EPO rising isn't a surprise considering - What all this means is, that giant Chinook generator pattern is not a terrible fit for the strengthening +WPO/+EPO. None of this hugely confident. Even relative to climo/modeling climo that is so. We've been observing wholesale hemispheric modulations that are unusual - considering the mass of the whole thing? Definitely either an artifact of modeling (somehow) or something weird is happening... where pattern identity become mere simulacrums that disperse like farts in the wind, and we're looking at something else entirely about ever 3 days. So I'm not completely sold that the above Pacific scaffolding is going to become history.

Streams to bank full and one or two oil drum garbage cans floating across the outfield of a little league park with levels dropping 7 hrs later.

I dunno.... At some point it's not a secondary. Secondary mechanics happen because the primary cyclostrophic flow runs into a problem moving through the terrain of the Apps ... then also because the colder/denser air wedged to the east of the 'divide' is also resistant. The air mass near the water/or over the water does not have these viscous limitations, so as the mid and upper level mechanics move east the "primary" gets stranded and the "second" low, being generated by the same mechanics that ultimately carried the primary, then takes over. When a first low ends up so far up into Canada it's not even on the map, and a low develops on the cold front down in Alafuckinbama, that's not a secondary. It's just a cyclogenesis. This is a Miller A low, period.

It's been an interesting 7 days up to this point with this thing. Back whence ...recall a model run where the GFS had this up just SE of James Bay. This run of the NAM has it cutting across the Canal. Seems to be slightly E btw - has it ending as parachutes in PHL-NYC. Nothing in Boston though which is apparently the way it should be now.

https://phys.org/news/2023-12-current-carbon-dioxide-million-years.html 480 ppm is the C02 in the atmosphere of earth at present time, a density not occurring since 14-16 million years ago, a time when "there was no ice on Greenland" ...you know, it occurs to me while reading this, there is, at present, ice on Greenland. Here's the catch. Prior to the 1700's, there was 280 ppm. In straight terminology, C02 concentration of the atmosphere have essentially doubled since the Industrial Revolution - in geological scale and comparison, that is virtually instantaneous. 300 years compared to an entire epoch? Greenland ice. This last summer's odd global temperature spike. It may just be that we are terraforming this world, faster than the physical manifestation have had time to catch up. Compensating larger forces cap rise, and then it surges..etc. We may see the temperature spike more commonly? Or even, perhaps one cataclysmic afternoon a portion of the land-locked ice cap in fact does what it has been hypothesized: up and slides off into the Atlantic. That's a different kind of tsunamis. That water level wouldn't flow back seaward. That is the new sea. I've read that Greenland has enough ice, on land, to raise the global sea level an average of 22 feet. It wouldn't take the entire 22 feet to cause catastrophic real time affects.

Things aren't so bad, really ... I mean, it's gonna snow, and snow probably at heavy rates for at least a short period of time, along the spine of western and NW New England. From the scope and scale of the N/A continent? That is a snowy anomaly - relative to season - for the "northeastern U.S." Case closed. This is a brief philosophical rant; but is true nonetheless. The problem is ... the "IMBY" devil. It's always there ... in constant battle with expectation. Ya know... 'perception is politics' - and politics is seldom very fair.

sorry... shouldn't have brought it up. ha. Nothing like setting off a weekend with people put into defensive anger. hahaha

probably not - the whining and grousing and having a reason to troll anyone with a hint of optimism seems to really be why/for a larger contribution to this engagement is really here.

I'm starting a thread for that one .. - most likely later this evening or tomorrow morning. I've been discussing the burgeoning PNA signal since two days ago ... We're emerging a system into a background numerical correlation. Those 'usually' come down to details when that's the case. Too early for such specifics, of course, but early heads for what (imho ) is maturing into a valid signal has been sufficiently met with success in the past and this is one of those -.

from a super synoptic scope that's a dangerous period of time.

I would definitely watch that 18th -21st period of time. I don't suspect that's merely an artifact of noise.

It's marginal though... 1 In my experience over the many years of modeling, marginality in runs routinely favors the warm side beyond D5 in guidance... We're out there around D11/12 with that thing so...it's probably all moot for now. In the old days ...through the 1990s early 2000s, most 'blue bombs' actually spent time as cold/CCB head rains when in the outer/ext range. 2 In recent years ... I've noticed a subtle difference in actual marginal scenarios - those that are inside of D4 or in modeling, so presumed reasonably accurate. Marginal actually has begun to favor warmth - I call that the 'flip direction' When we have been right on the fence in guidance that has a pallet of p-typs through an isothermal sounding at 0 C ... we've lost our latitude magic. Yes, it's a subtlety I believe may be connected with CC

Remember we were musing the other day over the lack of wind this autumn. heh. That backside of the NAM/GFS solutions would go some distance toward correcting that impression

The meteorology of this thing is interesting enough for me. Sensibly? hey, if snows even an inch after the frontal axis slips passed any location that will be 60 not 4 hours prior, that's notable. The whole situation may yet adjust more SE, too, so that description above may need to changed. I think we're getting some morphology out of a data relay off the Pacific that we don't normal observe ( as much...) in recent modeling. Bit of a wild card there.

Basically ... the models want to bring a last minute snow correction right up to the town just west of ...where ever Ray happens to be when this things passing through... For our collective want of Rockwellian holiday mood and specter, let's get him on a fairy ride to about 40 MI S of ACK and drop anchor. That oughta post-card our cause rather nicely

That's an impressive shift for present modeling standards in the Global s ...not so sure about the NAM's bi-polar tendencies beyond 48 hours... However, it seems to be behaving this time given what's going on with the other guidance et al. I'll tell ya, another shift of that magnitude, SE, and we bring snow collapse and real totals contention into the Berks - Monads axis

This is an important ( fascinating if you're a nerd like me ) aspect above ( bold). If true, it's a part of my faster hemisphere hypothesis - which has been recently corroborated by ... https://www.nature.com/articles/s41558-023-01884-1#citeas (probably other pubs unknown -) ..Anyway, it's "possible" that what you're describing may be an emergence of error forcing that was not as prevalent during the 'growth spurt' era of modeling technology in the 1970s-2000. The idea being that we engineer tools that suffice the observations of our environment - such that these tools' heredity may not be designed to account for a quickening atmosphere sending along balloons that sample the "wrong" region of the troughs and ridges. That's really cool!

Things to consider with a deeper sfc PP wrt wind. The pressure drop in the core of the approaching cyclogenesis along the boundary, offsets the gradient ahead of it, such that the winds don't respond as quickly as the isobars would suggest. It's real technical ...but on the back side, the pressure fall/rise couplet can induce a more active isollabaric wind response.

I've opined in the past that data assimilation has (apparently) significantly improved enough over previous generation(s) of the technology that we don't typically get substantive correction once Pac impulses relay into the denser objective sounding grid ... but, it is what is ... if this sudden increased trough mechanics goes on to be real, it would seem that is most culpable.

I noticed the NAM morphed the trough into a subtle but perhaps crucially more negative tilt/conserved strength, too, when comparing the prior 00z to this 06z. The 12z's rollin' in now.