Typhoon Tip

Using the old NAM FOUS metrics from years ago ... BOS 48048969471 07926 240917 42999399 54067989425 02209 090812 48000004 Looks just about split between snow and IP at Logan. That first 48 ( at 48 hours there ) is QPF in inches, falling through 980 = -1C, 900 = -7C, 800 = -1C That -1C at 800 does argue for an elevated warm layer, but as we've collectively noted...the NAM is a bit of a NW outlier... (*the model typically is at this range*) ... These #'s don't evince temperatures above the 800 mb sigma. The second line is .67" QPF in isothermal to 800, where that is +4C(39ishF) ... Probably that is toasting aggies at that temperature. Considering that leading up to the point in time ( 54 hours) there may have been a couple hours where it was at or warmer than this just above that 800 mb level. So that is likely IP ...and a goodly dose of it at that. Looking at ALB's numbers ...they stay below 0C at all sigma levels on their grid... so... the classic (technique+experience with synoptic features in play) / 2 connotes snow along Rt 2... with and IP intrusion to the Pike or just N of that latitude. By the way, this is mostly a latitude oriented affair when it comes to that.

Yeah the biggest issue is snow total vs sleet cutting that down from where I'm sitting. I gather that folks would rather not the sleet... lol. Anyway, I'm more into this for the general impact to society, much less the general impact to the delicate sensibilities of people trying to get to some dimension of nostalgic d-drip psyche for the modeling journey before it even happens. I mean, sometimes I wonder if that journey is more important than the actual storm itself. This engagement has evolved into something ( I wonder ) that is a part of that "60 Minutes" psychotropic stimulation addiction shit they covered as a problem to humanity by modern technology. But that'd be digressing... I'm probably not really qualified to get too embedded in snow vs IP... In principle this is a "needle thread" system. And the system is going to run along the "rail-system" where the run lays the tracks - if the larger synoptic manifold change < 72 hour out..that's more an indictment of modeling tech. And the ptypes are 'edgy'

yeah... yeah I know. Stopped short at venturing why - it's about as eye-rolling at the reader's side, as it is poking the hornet's nest to impugn the writer of that voice - best to just skip it, because it's never ended well. I mean no one since the beginning of on-line weather "forumdium" has ever said, "gee, you're right - I'm being flawed logical in order to ameliorate my neurotic agenda. I'll cease from such tact.. " Uuuusually doesn't end well in the exchange. One is just not likely to be influenced, or corrigibly gathered in once they are triggered.

Not sure I see why the UKMET is presumptively wrong, but okay.. Seems a bit impulsive. This event's coverage this week has been rather revealing when it comes to load-balancing group pessimism vs optimism. The group tends to merely register a colder appealed cycle, but look out! We're making failure declaratives at the slightest giga motion of noise - that cannot be avoided at 72 hours lead btw. The hyper focus to do so makes autistic savantism look like ADHD. Lol - Anyway, I still think the QPF is handling well. From the get go, some 5+ days, pretty remarkable synoptic consistency. There have been two distinct synoptic metrics in all guidance that really support QP going above the 'SWFE climotology' QPF suggestion. -- deep latitude +PWAT air source -- ancillary jet mechanics with superb lateral exit jet between 500 and 300 mb overarching N of the baroclinic wall/wave as it ripples underneath. The 500 mb is between this latter feature, and that upper air accelerating wind field. This should aid in propelling UVM slots and ( I believe ) we may see this punch into a deeper GZ than people think - possibly even as a modest behavior bust. ...this latter aspect is experimental... just sayn'. That's an extreme jet construct though. ...I suppose we should add fact that the idiosyncrasies of this set up has a polar high uniquely situated to really maximize BL resistance. This will have a compressed thermal packing closer to the boundary... Dry sleet affair where that happens. Also, I get the whole warm tongue stuff with a 10000 foot sleet column routine, okay - but this won't likely produce that kind of elevated layer. It doesn't have that kind of mechanical thrust between 850 and 700 to do so. This is unique in a sense ...it is maximizing QPF mechanics by accentuated lift of a higher PWAT air, out of less WAA above 1300 meters. This is the way it has looked to me for days. I'm pretty set on NWS snow chart - I like what they've got. 8-12" along Rt 2 ...with a smear down to Brian... and points N (ratio inflation notwithstanding). 6-8" along the Pike, increasing sleet contamination S. 4-6" with sleet and ZR ~ HFD - PVD ... 1-4" S. Shore with ZR/IP. Cape as usual will require an intervention by a team of specialists

We actually had that here, that 5 .. 6::1 sleet bomb, from that event that was... jeezus, fore' or aft the blizzard. But we had it climbing up the tire walls in driveways and plow-able deep. I was dweebing it checking out the particulates in the pack on top of the car and could not find a snow aggregate, yet it was like 4"

The QPF is not likely to narrow out and drop off so dramatically over S VT/NH like that with all those upper air mechanics. Tossed

RnotaGEM

That model is a pos

Who cares. 9” is 9” heh

That ICANT model would drop about 15” along EEN to ASH

Don’t have a problem with colder solutions at all… I wrote plenty of rational reasons and solutions why those colder solutions should be the ones to go with. Yet just because a couple of models tweaked north by whatever amt we automatically have to go with that… ?Sounds a little neurotic to me without having any specific reasons to assume that’s the case. And I don’t buy just because the vmax is n. Plenty of examples of all snow overrunning events where that was the case in the past. Wind max is not really overcoming the llv boundary resistance; it’s going to be a deeper colder air mass; the overrunning is going up a steeper slope. Think that it’s as north as it can go in those north solutions. The only way it can go north is if the scaffolding/confluence significantly changes. That’s certainly possible …will have to see

I’d have to beat 12 inches in a single dose for that to be true at this location northern Middlesex county

that 4-6" band down there could be the higher impact, too, with a mix of IP/ZR integrating that at 27 F

Guys ... Euro run is within the latitude of noise/margin for error for this range with some to even spare. There's really no need for reactionary - Aside, I bet dimes to donuts it's a pube south and outlier wrt its ens mean. The GEFs/oper GFS is my package of choice for this day. We'll see what future cycles do... 18z Euro goes tick S more, then tomorrow it goes back ... blah blah ..rinse repeat XANAX - thank you for playing the d-drip two step

That's actually impressive for an ensemble mean - even at 3 to 3.5 days lead. Obviously there is less divergence between the operational and the respective members that weight that average. ... heh. wow. But the > 6" being in the 90th percentile or higher at this range may be both one helluva testament to modern modeling technology, but a red flag to take this seriously. Ray or whomever mentioned the last hour may be right that this could either rival or become the better performing system for the season thus far, for the interior Pike to southern NH region. I also don't want to leave out the CT-RI crew. I think this can pin a ZR axis, with a roar of sleet/snow mix rolling off roof eaves and piling up along tire hubs just N. Not sure if that will reach warning criteria ice where does, but it's a nasty event down there too.

Yeah ... now for some attempts at sensible caveats. I realize my tenor has been rather bullish this morning - not just me! Look at the f'n models... But, the speed in which this event is translating through is nothing shy of an unsung amazement in this modeling cinema. It's actually sped up in the last day .. day and half -worth of runs. The primary seclusion --> "secondary" ( if we wanna call it that ...) commitment --> escape sequencing covers some 400 miles of x-coordinate distance from 06z to 18z Friday ... That's insane. The rad is going to be sending pixelation at haulin' ass speeds. That may limit this. Scott also brought up a very good point about the longitudinal aspect of the open wave, tending to currier the mid level lift away at bit of an acceleration over the model position of QPF. We have to remember when looking at QPF charts: that means as of the moment the chart is drawn... What that means is that it may not actually be coming down as hard as the QPF looks at that hourly/time in question - it could already be in the books. This situation could snow 4-5" ...maybe 6" in the IB/front-side, then 3-4" on the quasi CCB as the low is escaping. We go above QPF, but not hugely so, due to these offsets. J

Glad you put it that way ... Because ( oops ) I realized I said QPF in the context of present model suite, but what I was thinking when typing that was "compared to SWFE climo" - - i mean we both know that's usually a 4-6 with lollies to 8" type standard aspect. But because these peripheral mechanics are in play, we up-side this considerably. How far? ugh - we still have 3 days and truck load of model cycles, but I would not be shocked if these are upped by 1.5 if not a factor of 2, **IF** present synoptic metrical layout holds.

Been hammering this facet ( I know ...) but, in addition to you being not only right, this https://www.pivotalweather.com/model.php?m=gfs&p=300wh_nb&rh=2022022200&fh=84&r=na&dpdt=&mc= ...over -saddling the region with superb evac, **ADDS** to your assessment. Dude, this is going to over-achieve ( I feel ...) - as a back office/water cooler muse... But unless these metrics resolve differently, this will probably outdo the QPF max zones because there will be impossible to pin-point uncertainties wrt to meso banding ... forced by organizing frontogen/UVM slots by that diffluent mechanical layout there.

It does ... but this system has some unique synoptic aspects that off-set .. .The NAM's NW bias is competing and it's re-orienting the flow away from other guidance' that are proven superior at this range, just so it can sniff - mm ... red flag. In other words, it seems likely - to me - that it is wrong in the first place, so the warm tongues won't be there anyway - I haven't actually seen the run, just sayn'. That said, even in these solutions, it's still an impacting winter storm - ...it's hyper focusing either way.

Let me also remind y'all ... for the 1,034th time ... the NAM's 48 + range tends to NW bias with synoptic features. I mean that's part and parcel in why the NAM cannot be trusted overall, in this time range of present cycle ... because for other reasons aside, that one right there is a consummate correction. We don't seem to argue about that when all models are out to sea, and it is the lone model that has coastal clipping the area at 78 hours - go wonder.. .But, this run strikes me as almost meaningless due to that model's tenured bias, until such time as Euro/GFS blend ( and the GGEM's been very agreeable too - ), do the same.

Christ ..hahaha... over a 72+ hour NAM, where/whence synoptic precision - no less... - is the requirement? You guys are eye-shifting around like Gollum slithers between the lichen covered rocks of middle-modeled earth seeking the precious paranoia

Update: Deadlocked on a warning event for mix/snow issues CT-RI with ice option S, and tending to majority snow N of the Pike at this point. 4 days ...well, really 3.5 days away, and the 00z individual versions have very little spread compared to the blended/consensus is convincing. Some longer thoughts: Where is mainly snow... little pinging cannot be totally eliminated with mid levels tending N of ALB-Logan axis. It would need be a very elevated warm layer though. What this thing has going for snow enthusiasts, is that the +PP weighting/wedging in from the N is circumstantially nearly ideal in both magnitude and duration - not too suppressive; not sliding east or west just in time to f it all up. I'm actually rather impressed at how it seems to almost need to be there during the whole show. Interesting... I almost suspect the ratios to be better than 12::1 by the time we're nearing Rt 2 latitude along N. Mass, and higher N. Almost has a 1994 vibe with dry snow hosting pingers the size of small hail rattling the Pike with T's the mid to upper 20s. The cold wedge is deep rather tight to the boundary extending E just S of LI. It's a good candidate for a thin but important ZR band - obviously we'll need to finer tune these transition zones later on. The placement and power of a strong diffluent (evac) jet, extending slantwise upward from 500 thru the 300 mb, has been a leitmotif in the guidance for this, set to align from upstate NY to the Maritime of Canada overnight Thursday through the 18z or so Friday. That coincides with the QPF snow shield blooming over W-N-E above the mix corridor, but doing so unusually far into NNE. Without doing discrete analysis ... I'm reasonably certain that expansion is anomalous, relative to this system's centric kinematics, and is being driven by that forcing. I also think that stretches the UVM some vertically and we may see some banding in the snow as the atm tends to organize/frontogenic ... The SGZ tends to be less than ideal in these situations, but I'm curious if said extension by jet forcing might lift the growth into a better depth of the sounding. I don't think this system has quite enough punch to really toast the 700mb. It's a oddly detailed take from 3.5 days out, but frankly ...these synoptic metrics have been coherent in all guidance/ens for days now. The metrics are correct; I'm speculating (also) how they may synergize a winter storm performance... Excluding something extraordinary as yet to modeled challenges ( and modicum of correctness to this ... lol), I don't see these synoptics changing. This system is characterized by: weak centric mechanics benefiting from strong peripheral jet fields, with +PWAT anomaly forced over boundary with a steep angular ascent. That ascent then gets exaggerated ( some) relative to 1000mb type storm climo, by the former ... basically an over-achiever incarnate. A weak to low moderate scaled cyclone, with very good QPF mechanics, in an unusually ideal polar high position. I don't wanna get into snow totals yet from this range too discretely but ... the climo for this sort of SWFE ordeal is 6" with lolly's to 10? I don't have a problem with at minimum going mid way in that range... leave it at that for now.

00z GFS looks modestly colder but it’s moving faster.

Well like I said earlier and I still believe is the case… There’s a limit to how far this ordeal can go north. Models were pressed up against the synoptic wall. 18z sag not surprising. They’ll probably try to make another run or two at a North solution but they’ll keep bouncing off the physical limitation of mlv confluence, and llv boundary layer resistance

Heh typo