Typhoon Tip

There’s an interesting blob of plain rain on ptype surrounding my vicinity to ASH while sn w-e-n-s of it. Refuses to flip over there just wobbling around in the loops.

34/34 light rain cat pawing yuck

This is a GW/ Hadley Cell bulge into a winter BD scenario. All fields exaggerated because of that and you end up with huge polarity. All these lows are doing this now… I can direct you all the papers showing how the storm tracks all over the hemisphere suspiciously being pushed north because of the HC expansion with global warming. It’s fn up the winters. Also the flow being so fast is definitely having an influential impact on cyclones frequency and amplitude

Wind flags are pointing southwest in northern New Hampshire Maine now and the temperatures of slid into the low /mid 20s there

Ptype rad indicates snow here but that ain’t happening

35/33 light rain

Yup..just contemplating this even for here straddling rout 2 ... 35/29... close but less than totally inspiring. I'm thinking this is a 33'er until we start injecting. But I'm also not looking at the soundings so I don't know how deep this marginal DP goes. If it's 5K feet thick than we could wet bulb to 32.1 -heh

12z NAM looks more like a big sleet dump for everyone N of he Pike.. I mean, just eye-ballin' the FOUS grid

It's an interesting mico-physical question/problem... Almost quantum mechanical/thermal. Stepping back, I learned when very young that the 'liquid' water in rain below 32 F (0 C) that is freezing on contact, is in a super-cooled state, ...similar to why water in a fast flowing stream still flows despite the water temperature being sufficient to phase change to solid. The kinetic motion of the stream water ...or in this case, the falling hydrometeors (always loved the Met term!), is not being allowed to change phases from liquid to solid because in order to change phases, there is a "puff" of smoke ..ha, a small quanta of thermal energy has to burst from the molecules as they assume the lattice of the crystalline form. The kinetic energy of the moving super -cooled stream water, or the falling super -cooled rain drop, is adding energy at the same rate, thus...keeping the liquid liquid. The reason why the liquid in these circumstance does eventually freezes is because the temperature falls below the kinetic energy balance, and it goes ahead and changes phase - it's just a matter of the freezing point being "reset" a bit down the scale as a thermal subtraction/addition problem. What then makes this even that much more complicated is that in the case of falling rain, we have to deal with the veritical height of the falling column - and as others have indicated, the melt level inputs energy into the hydrometeoroids at greater quantities, in situations when the sounding is exceptionally sloped positively. Like...say, this time! Anyway, if the height of the < 32 F (0 C) that exists under the melting layer, is very tall, even a very warm layer won't ( likely ) add so much energy to fail accretion when the droplets of water make contact and shed their kinetic energy. However, that concomitantly means that if the warm layer is very warm, and the cold is shallow, there's going to be less proficiency in accretion - but, ...that's concept. A calculation may demonstrate that the add/subtract therms aspect isn't appreciably large. So, with a +5 C 800 mb warm tongue flicking over top a -6 C 925 mb ageostrophic lower DP barrier jet, with that melt layer precipitating liquid into that region beneath, that may be tall enough and cold enough to send a goodly amount of mass through phase transition and scalp fest the surface. It's just deep and tall and a long time to feed lower DP air at an ~ constant, which helps cool the rain drops faster. Which brings us to another aspect... that final puff of released thermal energy when the molecules formulate into crystals, that adds heat to the column. An initially cold ZR will eventually torpedo it's own ability to ZR because of this process. I've actually witnessed dead calm ZR at 19 F end up 33.5 drizzle inside of 6 hours because there was 0 input of lower DP air to keep that thermal imbalance in play.

NWS is missing a critical conceptual component to this thing when reading their AFD's from overnight. This excerpt exposes that, ".. air located around 3-4kft at about -6C! Shallow cold air likely gets replenished later Mon into Mon night as frontal wave emerges off the NJ coast. This will increase low level northerly ageostrophic flow across southern New England. The net effect will be for the high ..." What they are suggesting of the storm moving off the NJ coast enhancing the "draw" of colder air down from the N is true at a baser fundamental level, but that is not ageostrophic! No, that process is a standard PGF (pressure gradient force) mechanical response. The ageostrophic forcing comes from a mass discontinuity that is set up because of a planetary/atmospheric topographical interface circumstance that is unique to this geographical region. Namely...the ~ N-S cordillera with the sloped to sea-level coastal plain elevation to the east ...and when cold air "folds" around the northern end of this topographic circumstance up over eastern Ontario and N. Maine, particularly when it's back-built by confluence/DVM supplying more mass, that dense weightier colder air starts filling in the described region, and will do so disproportionately at positive anomaly, relative to the existing pressure contour suggestion that is on the synoptic charts during the invasion process. It's the Earth-atmosphere interface doing that, not the PGF. That is the ageostrophic forcer... The low coming off the NJ coast enhances the motion of air but that's not causal...The ageostrophy is coming because that wedge of air is doing the work... wedging under whatever existing pressure gradient- balanced geostrophic wind there is in place. That is critically missing in their content ... If this were included, they might have modulated for a colder profile N of CT/RI borders in that region there... They speak of the initial condition of -6C at 4-6K feet as an impressive core of cold, offering to elevation sleet and ZR bomb in the Berks with more IP the Worcester Hills and ...and that's really clad work. But then they later only mention cold as reenforced later Monday afternoon ...almost as an afterthought in the cadence and style of delivery in that AFD and that's under-evaluating what is likely to be a pretty impressive flag touting invasion of steeply colder air with that, and it will probably surge farther south than even the finer-meshed guidance are assessing. That said, these are not intended to be dramatic terms or turns of phrase, either. Just a bit of a clarification. Their current headlines and Warn/Adv layout is ..prrooobably sufficient either way, because the general public doesn't delve this deeply ..much less have a clue what the difference is between ageo and PGF balanced mass fields even mean. May as well be talking about the far side of the moon. Even in a deeper more impressive cold surge mid or 2/3rds of the way through ( which to be fair, I was thinking that would happen earlier in time so I may be error..but given to their lack of aggresivity with that factor, they could be late, too), much of the QPF for southern/SW zones will be light, thus...this won't matter. Although, things my be error-dicey up there in NE Mass/interior SE NH where they've gone Adv ..but again, phew...the public doesn't really pay that close attention. Just a quarterbacking from the office chair moment ( Caveat: ...this could all pan out true by behavior, and still we end up annoyingly too warm by a degree ...)

It’s not correct guys

I don’t know the thing I don’t like about those freezing rain products is that regional icing events tend to be more normalized mass accretion everywhere than all that cutesy mottling that’s down to town sqr sizing What’s with all that blotching like that ... it’s not gonna be like .63 of ice two pixels to the left of .23 like that that’s bullshit

And straight rain in Tolland ... yeah that’s interesting

I know it’s ridic there is a larger sort of synergistic argument tied into the expanded HC ( dreaded GW) and the increasing winter time gradients perhaps favoring that sort extreme variance Scenarios. No takers? heh. Yeah we seen that before those crazy backward sloped sounding but this is probably among the most severe I’ve seen that regardless of what it really plugs into causally But yeah that’s exactly what I mean it seems like it is a faux artifice of the models doing mass balancing or something. That couplet’s no accident if ask me and underscores the effect

I don’t know I’ve seen the models do this before… Particularly in this 36 to 42 hour lead window. They seem to wanna figure out how they can make the sounding just the most absurd severely inverted as imaginatively possible. Almost like they use each current to force the other ones countercurrent as a mass balancing or something and it ends up over exaggerating the warm over excruciatingly cold low levels. Then get closer they ease off the throttle either aloft or below; but in this case I think we’re going to pull back the warming aloft maybe a tick or two but it will make it more reasonable. I just see the cold is being a higher confidence scenario below

Mm... I wouldn't be presuming anything has be after January's first week - don't have to look far for the advisability of doing that, this winter storm ( hello ) happening in an utter dearth of antecedent teleconnector suggestion. Jesus - That said, ...yeeeah, it's looking pretty bleak if one employs the American indices ( ha). Ugh. In fact, winter over. Haven't seen a signal that bad since the infamous early January of 2007... That said, the D6-10 EPS would argue for a better winter appeal over the U.S.. not sure how well that is teleconnected to the rest of the hemisphere, but that's a very cold look at 240 in that blended mean. The operational not really being an extreme outlier, is actually a sign that the signal may be potent - if perhaps counter intuitive. The impetus being, the mean is always banal compared to the individual member so not seeing that means the weight/correction vector may be toward more amplitude. anyway, it's not as discouraging as the American cluster is all. Huh ...but just looking at the CDC my god. You'd have think the ensemble system is just f'ed up and broke, and needs to be emptied and reset or something. Hard to believe every domain space is biased the same direction - that's really almost pushing physics.

The 18z NAM offers up 0 or < 0 C at every sigma level from 800 mb down to the tarmacs for Logan during the first 12 to 18 hours of this thing. That's a tick down by some, and it now is even colder than the shaved .5 C Euro at this point. And if it were not [ probably? ] for an obscenely elevated warm layer, that would be probably 5" of snow in that QPF realization, prior to ZR intrusion. If not, than folks thinking sleet are in for surpriiiiise. I'm also noticing a fairly potent IB signaled in there, too, with 9.2 units of UVM during the front work - not bad! Before quells into a more middling lift on-going saturation, but by then we are soaring at 800 to 4 or 5+ C so that's sleet and ZR most likely at least to that latitude over eastern zones. In the interior, this sags by some..how much is now cast-able. But I would suggest that is also offset by the fact that this is warmer WNW of ORH in this type of synoptic ordeal...with essentially what amounts to a powerful BD advection coming in around a third of the way through, a marginal cold rain/ice/IP situation profiles downward and becomes non-liquid in character at that point in time. It's likely IP in ALB while snowing at the east end of the Mohawk Trail for a stint during the band of instability burst. Overall, after brief snow, looks like mid or upper 30s southwest of HFD where cold rain and a few pings, to low 30s/30 down rt 2 with IP and mangled aggies, while it may be heavy IP/noodles at Logan. Then everyone is over to IP NE, as we convert this to a moderate infrastructure ice concern ( more?) as said NE thrust arrives and probably sends a wave of crashing DP /temp deep into CT/RI underneath ongoing WAA way above. That's what this looks like to me, and even the higher res mesos will under do that fantastic static stability/BL forcing of having a newly fresh polar +PP wedging in like this. It's just going happen this way I feel. If not... oh well - otherwise consider one's self warned. I'd say if anything warning would be met near that interface of IP and accretion where fall rates and temperature combine for proficiency. Where it is snow/IP around Manchester NH, may be high end advisory - until later periods when coastal evolution may enhance a temp CCB in that region up through coastal Maine.... It's tough sending headlines when you got storm acting seamless across different intervals. Heh... pun intended, it's like "the cloud" storm.

That's an interestingly discrete attempt by the finer meshed meso model type, to assess elevation/ridges and hills being high enough to poke over the blanket of BD'ing cold drain like that. But, I bet that's error ...not so much for that handling - valleys most certainly will be the last to scour out...but, because the uber finite grid is local scaled and is probably not seeing the total weight/potential of the +PP over eastern Ontario - modulate this product for more mass input would be my suggestion and that probably submerges those 1800' hill tops in the cold slab. But also, give the model a chance ... I can't imagine a scenario where a 48+ hour forecast is really in any NAM-derivative's wheelhouse. It may get that low level cold slab thicker in time.

Ironically... if perhaps for my own lapse of communication, I am not disagreeing with antecedent air mass point. Altho..we are getting DP recession now, and it's deep-ish'er in the atmosphere than folks may think, based purely upon the absolutely stunning sensible appeal out there right now - hope you guys actually appreciate. Beautiful out there...my goodness. Anyway, we shouldn't be fooled by the appeal - this is a new CAA and typical in overnight fropas, the CAA lags during the morning, so we probably won't know or get a sense to the skin what this is like until the sun kisses the horizon and it gets tit-nipply fairly quickly. It may sound 'bush' to rely on that but ...heh, sometimes it helps to be kissed by the girl to believe she digs you. As far as this system: the details show ... there are pressure rises happening, particularly in the Euro you can see this ( perhaps the 24 hour freebie intervals in a twist, actually helps elucidate this phenomenon), over Maine about 1/3rd (~) of the way into the event. When that happens I promise people...there will be a pulse of ageostrophic acceleration taking place E of the mean elevation curve of the Berks-White Mountain cordillera. That is going to impart the lower DP air and that's it - game over Now, this is based upon the total synoptic players in the models ... which by that bold italic is thus predicated on the assumption that they are oh ...80% correct in the totality of this thing's evolution. If these structural components verify to distractingly ...then we gotta field a bunch of miss-guided criticisms I know -

Know what'd be cool.. ? I'd like to see an accurate ( no doubt, someone now is going to either miss the adjective 'accurate,' or think accurate applies to them, and level cran-up drawing of it at us now...) reanalysis of the 1920's ice storm that occurred to historic proportions in SNE. I'm pretty sure substantive icing took place right to the coast in that one. I've read weather-science 'attempted' accounts and they did speak of having a polar high over eastern Ontario - at least in some semblance, that specific part rings a bell.

Not sure I agree there... It'll be interesting to case this one and see ... I bet you there is even a pseudo-tendency for a CF ...not super discrete, but amorphous? Such that you'll find that once the barrier sets ups, the atmosphere will use it to drain the pressure discontinuity from D.E.M ...which is being fed by a near stationary "fresh" cold source of +PP N of Maine ...and, it will not be impeded by any east flow ... The other aspect is that even if the wind did turn more E and punch enough warmth clear to western Middlesex County, which has never happened under these circumstances...the air mass arriving on that trajectory is not "stagnated" oceanic air - it's also curvilinearly coming from that same cold source up there... That matters thermodynamically in subtle ways. I mean, these are my experience as a Met growing up in eastern Massivetwoshits over the last 35 years of my life... Now, that does not attest as to the quality and fulfillment of that life, ..just the weather-related peregrinations it has offered along the humiliating, crushingly lonely journey

I think so out in the farther SW burbs of Boston too... but that's just me - agreed in general ...

Well... yeah, if the situation should ever arise where that is more clearly likely, they probably would ... plus, when it is time to do so. Neither of which is now - you do realize that NWS typically does not issue warnings for 3rd and 4th period events save for rare scenarios? ... just checkin' But for now 1/2" of accretion does not look like a slam dunk for you ...sorry.

They should go with a watch " a little " farther south and east of present, with the perfunctory AFD statement/turn of phrase included that southern and eastern zones will likely be converted to Advisories, but we'll hold off Advisories for now, as a good bit of this event will be taking place in the 4th period... or words to that affect. So, no - not what you're glorifying

This was an ice storm look since D8 lol... but yeah. I'm looking at ALB's NAM grid and the model's capping a +5C 800 mb layer over an isothermal 0C temperature curve ... over eastern NY ?! zomb... Meanwhile, the Euro ...being inside D4 mind us, is showing rising fresh, new, polar high pressure atmospheric cold mass into D.E.M. ... Btw, given the synoptic indicators ... NWS will need to expand that watch all the way to I-95 over eastern zones...probably down into N RI at some point. It is unclear why they have not included those areas anyway, other than - I guess - trying to out-think the models, but I suspect more likely there is a dearth of local studies/climatology unique to this region, scaffolding their forecast philosophy. When there are big, fresh, new polar highs arriving/wedging from eastern Ontario, such as that that's being indicated by the most trustworthy guidance at this particular time range... mmm, I read their discussion to be fair, and frankly it does not translate like they are self-reliant in the 'existential' concepts, and more so like they sought consensus with surrounding offices - which I'm sure is protocol and is fine. But it's interesting that with a bigger of pool of brains in that discussion, one would think one of those mind-pans would have instructed a hand-waving, and honed the concepts of ageostrophy/"barrier jets" and that there is less likely an E turning of the wind at the surface Sunday night. good luck! I could be wrong, ...and it's probably a tedious critique ...considering no one outside this social media will ever be made aware this missive was composed...and, we don't matter, and, no one gives a shit anyway... But for the virtue of wasting my time, I felt it worth to mention