Typhoon Tip

mm..it's not likely to be protracted - as in multi threat spanning a week to 10 days... Probably, once we get one it's done. The NAO will likely retrograde and pin our beast in place and then the two wane in tandem... as the storm drifts away kind of thing. May be another NAO pulse 10 days later in March - I'm just basing that idea on the seasonal lag/blocking tendencies we've seen as a repeating spring theme over the last decade. I feel that is tied into changes in the global circulation mechanics which i won't get into here.. But it has been reproducible, regardless of the exact cause.

Yup... that signal ( actually begins 27 and end Mar 3 if want to be fair to the totality of thing ...) is an 'index-scaled' scenario. I think I might have even mentioned that early in the day but I've been doing this like a mad man.

I actually gave this a shout out over in the 23rd thread... ha -

that's why I'm keeping this a moderate affair ... for now. I mean, there's not lot of wiggle room to make this more than what we are seeing... It's a pulse of pretty significant wind mechanics zipping through the interface between the PV and the S warm wall... The polar boundary is just what Will said, more like a stationary front with flop over being pulled up the elevated frontal slope by restoring mechanics on the equatorial side of the exit/lateral/entrace jet max passing by just N. Gfs still carrying the 28th event ( btw...) not to stray on this thread... That's a potent consistency in the GFS, now also inside of D10 ... pinch us, we're almost spoiled here! no but the GEFs have been trending to an actually vision, and not just buckshot from Michigan to Bermuda...

jesus ... what'dya reach for the powdered concrete instead of the corn starch. How does one just manifest clots - seriously.. sounds scary

It's not a typical SWFE .... Like I just said to Will... the frontal structures and the forcing aren't gaining latitude. Think of it like this ... a warm front extends from southern Ontario to Boston, and the MCS travels along and to the right of the boundary ..pulling it back S... not sending it N

Personally believe it will continue to correct S in this case - ...it's bit different than the typical SWFE. For one, it's not really lifting along that type of azymouth. This is running longitudinal, straight W-E so the advection is almost exactly compensating for the cold exertion beneath, and they end up in stasis - but where ? In other words... we don't move from heavy snow to weak IP to light drizzle then end. We stay in our ptype hood. I'm imagining mid way Pike to rt 2? with snow --> IP along the Pike then ZR... Ends as freezing mist, but the event has a second pulse Friday as the 'main low' trailing smears through. Redevelops you ptype, ends as flurries... nasty cold slap Friday night sets up a spectacular Saturday morning scenery..

Having said that ...I do suspect south corrections may overwhelm any attempts to bump back N - but wouldn't totally rule out a run or two setting off panic tones... LOL. This doesn't appear to be a situation that would wholesale end up back N to me. But we'll see

yeah,... this is a moderate impact event, overall? I wouldn't expect more, just in general. Snow... In fact, maybe less where icing. Typically 2/5ths of an inch starts the timbre sound off, and weakly hung utility points ... really you need 1/2", which I believe is the warning criteria for ice. I don't see this happening much beyond that scale. The cold is likely - I see it ...- to be really compactly compressed against where it just ends up 33F... such that there ice region is very narrow. Also, it's unclear if the lift mechanism hangs over the icing layer, or if it peels N and leaves that region with pixie dust and freezing drizzle making what rimes sort of 'glow' pail. Overall, I suspect this is 6-10" of snow where ever is getting charmed, and 2/5ths icing in a narrow band S ... leverage in some IP in between. We may have furthering trouble a few short days later with a more index-scaled signal.

ha... oh man. The icon - yeah, iconic symbol of how NOT to formulate an atmospheric model. Sorry to throw it under the bus and nothing intended toward the Germans but ..... no, don't do that.

I'm not sure exactly what you're asking? ...is Philly in contention for this..?? If so, no ... this is a gradient contingent scenario, compressed along a relatively narrow corridor .... like I said, 'probably' within 150 miles N/S of roughly I-90/Mohawk Trail/SNE/CNE/NNE

For now I'd say that is higher ice to IP ratio/result ... from there up to the Pike and down the Pike length... but tuck getting under way mid day Thursday - if it is even identifiable at that time, probably makes the eastern end of the Pike more IP/pixie dusty.

At this range and considering the recency/complexion of the various persistence' in the guidance ( cross analysis, too), the the risk associated with this somewhat protracted event is situated along I-90 in NYS through roughly RUT-PWM for snow, where astride this region along the south by some 200 miles ( give or take) there's likely to be a gradient of IP, ICE, then cold rain. Snow amounts look to be 6-8" with more in favored elevations/cold ratio loading ...and/or impossible to predetermine meso banding - which I feel there may be some in this latter aspect. This is an overrunning scenario, with a powerful left exit/lateral to entrance jet structure associated with the main short wave mechanics...torpedoing by N of an intensely defined low level polar boundary. That boundary is likely to be very intense at elevation, up the warm boundary slope, where it is then encounters an evacuating circumstance. This will enhance lift around (likely...) some frontogenic structures/very narrow. I wouldn't venture a precise idea on the width of the snowing region of this total event, but would suggest it is not spread out all over hell's creation in size. IP vs ICE and where? Firstly, a cold thrust/"tuck" showed up yesterday at finite analysis of a lot of guidance ( Thurs afternoon...). That is/was built into our climate, and given the general synopsis as it has existed in the guidance for days ( really...), the possibility is/was assumed in this particular scenario. The models outright showed that happening and still are. There is an antecedent building +PP over western QUE that's put there by PV confluent against the southern ridge wall - that is a large scale scaffolding that is physically connected(able) to the smaller scales. These finite lower tropospheric features in the guidance are thus less likely merely noise, given that totality. Trying to establish some confidence in that actually taking place, because it matters greatly on who gets affected by IP vs ICE vs cold rain across the region of southern NYS tier, to S of ~ rt 2 along N Mass. I personally believe these above cold implications are too overwhelming to ignore - and frankly...I would not bother down playing them in this case, unless the short term on this corrects abundantly N. I don't believe this latter adjustment is very likey, however, ...because this overall 'needle thread' longitudinal event is being "locked" into a position guided by the PV press against the -PNA/La Nina persistent/circulation base state. I suspect this is why we are seeing such a persistent signal for this overall event, it's got the deterministic advantage of competing titanic forces, which by virtue of their size ...command a lot of physical proxy on the flow set...etc. Basically it's a higher confidence total event. The details will be ironed out during the next 4 or so days.. .but I feel pretty confident this needs its separate evaluation window at this time. Special considerations ... - QPF may be a bit of a challenge particularly S of the snow transition to IP axis. The excessively thermally compressed overall nature of this in the N-S, combined with the idea that 'lift' may in fact move off of that mix axis, means that precipitation could ( not saying it will...) end up shredding and become more intermittent in nature from lower growth. In fact, ....IP could relax to pixie dust between rt 2 and the Pike, should the suspected cold acceleration arrive under a ceiling where the lift has moved off. This is just a possibility... Lots of potential for cold wedging here, with equally 700 mb push over top may set up more prolific fall rates in the snow growth areas of the soundings in Central NE axis. - the trailing 'main low pressure' may offer a burst of heaving returns as the system is exiting.

No shit ... who woulda thunk

Looks like the mid lvls ticked warmer but the llvs ticked colder.

What a mess on this run in the interior

Reiterating … … the whole hemisphere en masse is tweaking S, mainly wrt the PV. Been monitoring that. Every time it does … the depictions have moved with it.

Kev' if you really are buckin' for an ice storm, you wanna probably halt the suppression in the models now. I wouldn't be surprised if this ends up more snow down to the Pike to be totally honest. It could. Again, as I outlined the other day, the greatest sensitivity in where the conduit axis for this mess sets up is along the interface between two dominant forces: -PNA/La Nina base; PV anomaly in Canada. That hasn't changed,.. but there are very small incremental S adjustments going on with the wholesale PV position ...thus that axis goes with it. That, and the fact the the models will not be able to likely resolve the BL cold by several tens of miles up to 100 or so, ...all told, you probably want this to stop now or we could milk sun and bitter cold PF to Dryslot, with snow ALB BOS and IP in NYC. Having said all that... PV repositions N by subtlety, this lifts back N summarily.

Not sure if anyone caught this ...it's fairly tedious but I still paused when I saw the GFS, at this range of 138 hours ( 12z ), dropped Nashua's 2-meter temperature from 31 ... all the way to 19 F between 18z (1pm) and 00z ( 7pm) Thursday. That's a like tuck jet on steroids. I bet that would whip flags and come in like a BD white noise.

wouldn't it be fun if it ended up down here and y'allz tokin' on cirrus bongs ?

yeah... let's get greedy ... hahahaha j/k

I'd be careful with that interpretation if I were you... I wrote about this in an earlier post, warning of that allusion to finally having the S-SE warm wall in abeyance but it would not in fact - or might not I should say... - actually be that way. It's just compressed to where it looks like the right configuration. But the large number of isohypsotic gradient and the associated base-line wind is a trade off between the ridge structure, replaced by velocity. The ridge is conserved that way ... It's insidiously hidden. But it is an interference pattern. I remember a -NAO like that in 2007 late Feb or early Mar.. ex Heh, near the end of Eastern's reign ... There was all this excitement and optimism for the NAO arrival and it showed up ... all we got was 4 days of gusty gelid knuckle achin' cold winds

Maybe a two pulsed ordeal. The first, the 23rd, wraps up early on the 24th ... then clears and gets windy with falling temps through dark. It's possible there would be WWA and/or WSW zones in activation while there is a Watch posted for the 26th, which starts late on the 25th.

Euro sends another ( the 26th one) right on the heels. Like 24 hour window between it and the predecessor 23rd ...which really doesn't completely wrap up until the 24th. It's interesting because the wind tries to turn S just before, but the turn around between systems is outpacing that the ability to warm by so much, it ends up just the same sort for gradient snow/mix/ice/cold rain - very similar looking actually.

wow... I was just checking out the 2-meter ( GFS) for Thurs afternoon as the TT depiction has it... 18z has 31 at ~ ASH... 00z? 19 ! zomb