Typhoon Tip

It's annoying and unpleasant outside right now here in Ayer. There's just enough high clouds to dim the sun to a glow and not really warm feeling. Meanwhile, it's windy. So 42 may as well be 24 ... Helluva way to kick off a warm spell. heh anyway, not surprised. It didn't look "nice" out in the charts scoping this prefrontal environment. It looked to windy then.

That correlation may be so ... but in present practice, it makes it hard to know if that is causing this or not when as noted by CPC analysis, the atmospheric circulation has been decoupled in recent weeks. If it is decouple, that can't be the forcing mechanism - But that may be fine in the discussion. Because, it's just as plausible that eastward biased cool SST anomalies typically do disconnect/'uncouple' It's an interesting question/topic no doubt. That would take a tedious atmospheric reanalysis effort comparing all historical La Nina's that fell within 90% tolerant analogs to this one, by some red-eyed brain flogged grad student thinking they might've bitten off more than they can chew in their chosen thesis directive. I mean it's like... 'was the La Nina analog in x-y-z year' Then compare circulation modes then and now as to their uncoupled states.... I guess you could do it. But it would be too levels of research. Amassing suspect seasons, than calculations/mathematical physics to prove it. AI/super computing would be helpful in the latter. digressing - The HC stuff is speculative, btw - I only push that across ( as a posit) because I like cause and effect? I don't believe things just happen for the sake of their existence. Everything is caused by an event, or an aggregate of events in constructive(destructive) interference, in nature - in reality really. The atmosphere is no different. There's a reason for these ENSO disconnects. There's a reason for the faster than normal atmospheres. If the boreal winter heights are still deep enough, and the HC lingers into mid latitudes even fractionally... that increases gradient --> speed takes place. And here's the the thing that I think would be critical in that assertion- I don't believe the initial HC studies have it right that the expansion is only happening in the summer. That's suspect ... Firstly, the radiative forcing in the tropics doesn't dim below the threshold where the atmosphere would no longer gain diabatic energy, below 23 1/2 deg of latitude winters. It's not that it is not happening, it is being expressed via wind velocity. The compression of the heights speeds up the flow, and that is the machinery that conserves the energy of the expansion - it's just being converted into stronger winds.

I don't doubt Scott's data there ... I spoke about this a while ago when the RMM first began signaling a right side RMM wave momentum. However, I have a few caveats in tow. As CPC's publications noted at the time, the atmospheric circulation mode had uncoupled from the La Nina signal. I have my own hypothesis about these ENSOs and how and why they have done that a lot in recent decade. Warm or cool ENSO, both have demonstrated at times, poorer correlative behavior during the heart of the respective cold seasons hosting them. I mentioned that aspect last autumn to Ray/ et al in the ENSO thread over in the main forum space ( or perhaps here - can't recall specifically where). I posited ( and still wonder - ) if the expanding Hadley Cell phenomenon that is documented and scienced as related to the on-going CC, may be tending to supplant the forcing ability of the underlying ENSO. The way it works ( in theory -): HC expanding might go beyond and effectively engulf the the region that would otherwise/previously be the forcing interface with the westerlies. Once that happens, it does not force as readily... It's pretty simple: the expansion disconnects the ENSO forcing from R-wave dispersion. In any case, something is causing these uncoupled circulation modes. Regardless of what the universal cause is, that trend had me quite suspicious, if not suspecting, a similar observation to take place again this winter - here we are. The blizzard and the events prior to it, they were all formulated during a poorer La Nina coupled state. That said... 10 days ago we were looking at robust RMM prognostic for wave strength in the GFS cluster ( it should be noted that the ECMWF was never as robust as the GFS/GEFs were ). Risking hypocrisy, I went ahead and agreed with CPC at the time. Because the right-side RMM wave spaces are correlated well with the La Nina so well, that presence of momentum passing through might be enough constructive interference to trigger the circulation mode to re-couple. "IF" so... that would put an end to the cold loading... end to colder profile storm chances... effectively, ending winter do to it happening in mid to late February on top of an already stressing, CC-related early spring tendency - also a recurrent yearly observation. If the MJO wave is weakening ... which that present diagram now indicates ( new ), that changes that map a little ( imm abv paragraph). That doesn't offer quite as much constructive interference..

It all counts ... absolutely. See, it's part of the 'abstract' stuff I was hinting about. I mean, these little blockings? Those and the eventual onset of the coherent -EPO, all of it is like "prone to occur" in the hemispheric physical "foam" if you will. But prior to the actual materialization of them - the given model run is probably less important than the fact that it keeps happening - because the latter signals that it's really coming, matter of when. I've referred to this in passing turn of phrase as "super synoptic" signaling. Gets into fuzzy logic... Anyway, my experience in the past is that when this happens, the change then gets underway and it pays off faster rather than later. I don't think we are waiting until yesterday's day 11 through 15 to see activity unfold. Regarding the other bold... this week - I suggested back then - had a chance to correct S, because we had already seen a similar one do so just 10 days prior... mm, the footprint pattern isn't hugely different to assume that wouldn't redux. But I agree, this is a different kitten altogether, with these other conceptual aspects pushing against the levee of that front.

An impressive array of indicators unfolding as of late, that's for sure. Some of them are the traditional methods, but some are less than very easy to describe. More "abstract" interpolation, but they are all pointed in the same direction. Short: I would not count on the Euro's warm up next week (132 -168 hr ~ ). In fact, I raise possibly at this point that whole warm up is already gone - perhaps we're just in wait of seeing it physically manifest on the actual model depictions as they grudgingly capitulate. Longer: Discretely, the PNA correcting upward has not been linear. It's log over the last three nights with apparent acceleration. As of last night, the numerical layouts over at CPC have 2/3rd of the members with what would almost have to be a prelude to whopper correction event over eastern N/A for D10 - yeah...a bit sooner than we surmised yesterday. Why do I think so? More abstractly, trends originating from the different scope/dimentions. That gets into more personal speculative methods so just leave it at that... I tell you what, I don't believe the emergence of coherent -EPO, being led by quasi -EPO-like cold loading happening as a presage physical circumstance, is a less than meaningful coincidence. The hemisphere may have been morphing before our very cycle awareness. Check out the overnight GFS/GGEM with 1050 to amost 1060 mb high pressure parked over mid Quebec province? zomb! Euro's stacked more than 1040 mb along similar transit timing and position, yet this latter model shows less inhibition placing it's sfc boundary ( mean ) from BUF-N VT-ME ...uh,strikes me as vulnerable to a S correction - the fact that we are talking beyond 144 hours, notwithsanding. Despite the verification scores and/or reputation earned, the GGEM is unfortunately a very possible layout, and that solution is probably ice when then adding to it, typical BL aspects at this sort of time lead. So you have ALB in an ice storm, and ALB in a 70F ... in the operational variance. It's not impossible that we have a large scale (unsure of amplitude) ice/mix ordeal setting up from the Lakes to southern Onatrio to NNE spanning a couple days worth next week, with option S, in spite of the erstwhile expectation for huge warm up. I am also curious about a bigger, powerful type cyclogenesis somewhere in the E... perhaps 3 ... 4 days later.

Heh... that's like a La Nina anti-matter

that's the difference between cogent sounding jest vs coming off as a complete goober - just sayn'

Unfortunately for snow/storm enthusiasts... we'll have to wait for anything target, should anything come of it.

Agree ... I wasn't sure I was ever buying the season exit warm up scenario ... The EPO was falling/ neg-ish out there, and now after we've waited ... here comes a cold loading into Canada. Go wonder - The negative PNA showing up in the nearer term GEFs is not extended very far beyond, either.

And honestly ( imho ) the verdict is still out on how warm this warm up is going to be. The warm up appears to be more of the single warm sector shots now, as opposed to those unabated ridge expansions. If it is kept to the former, I feel sort of meh about any EPS accomplishment there. It seems the Euro cluster was pretty close to the larger ridge expression, and that's not likely to occur. The PNA over the long haul appears to be +1 --> -.5 --> +1 ... and during that middle range ( this next 7 to 10 days), we see a couple of warm sectors kept briefer by virtue of a very fast hemisphere not allowing any regime to stick around all that long... ? That seems to fit seasonal trend anyway. By the way... no one asked me but the end of the week seems lesser and lesser like a 'cutter' It looks more and more like it's just a big powerful cold front. not that it matters -

What about the GEFs ... The EPS mean has been more unstable imho. Having said that, the GEFs looks like it has a -EPO/+PNA dominating the pattern as we go into the end of February and into early March. So that would be the next period look for a threat - LOL

heh...last couple of cycles of the GFS attempting to morph the end of next week's 'next' warm up into fantastic ice storm... Wee bit different than the Euro's complexion. 200 hours + tho so ...

Wondering why the PV has been biased on this side of the hemisphere this year like that. Seems to be a recurrent theme to set that up - although that may be the first time I've seen it closer to the D. Straight/Greeland area. The flow between it, and that drapery of warmish heights along and S is creating a hefty wind problem for modeling S/Ws... Sucks. gets a bit annoying. Fast flow type has been a plague in recent decade, too -

I mean it's still winter. We just happened upon a shit show pattern, one that probably symbolically fits the shit show winter it is nested within.

Right - I was mentioning this earlier ... Almost don't have to look at the index numerology with those occasional -30C 850 mb cold plumes that keep loading over the Canadian Shield, they get there by EPO deposition ( neg phase)... Question is whether that influence into the mid latitudes and below over the CONUS.

oH believe me ... and it's a repeating climate signal at this point. ENSO cool/warm aside... didn't matter. We've put up 70 to 80 episodes in Feb and Mar during an unsettling number of those months spanning that last 15 years, to much to be ignored - though given the bias in here, it tends to be LOL. No, but I take looks like that seriously these days, at this time of year, because the elephant in the room also added to that. We're on the fence with index/indicators... Seems every couple run cycles the modeling veneer finishes warm, then cool...oscillatory error. We know whatever transpires over the next 2 weeks of the month, it's not going to be 'on the fence' so one way or the other will likely win.

To add insult to Phin/PF ... the Euro with a run at 70, D10 ... not that it'll survive 10 days of fractals in the models and actually happen, but it's the gesture that counts... LOL

Yeah it's kinda boring looking ahead. Maybe the week's end system is interesting for wind and ribbon squall if that's a kick. Originally, I thought that had a chance to flatten like the sleet event last week - it too was a flat wave cutter when it was D5+ ..etc. But still waiting for any trend to even manifest is a paint peeling. Otherwise, watching indices modulate off the warm throttle, but not conclusively so... such that varied outcomes not sufficient to induce much, oy ... None of that is exactly lighting the stage up with entertainment really. It's like we're sitting in the auditorium with half illumination watching set dec move props during sound and production checks. More like an opportunity to check out. Maybe engage in other hobbies ... check back in once in awhile in the off chance that anything might emerge.

The cutters are likely legit. I'm assuming your motivation surrounds warmth? For those in the spring/warm enthusiasm side: the numerical PNA teleconnector at CPC has shallowed some regarding the previous negative index mode. Still has the index slumping off.. but, keeps the -PNA rather weakly so - centered on D7. In fact, it's really only down -.5 SD, which is not a very convincing look. Prior it was -1, with a more coherence. This shallowing is then followed by the index rises back positive going through week 2. I realize the MJO this ..and La Nina that... and climate change this ...and all that, but these are more like garnishing indicators and will take a back seat if the seasonal persistence ( by virtue of already verifying...) decides to return. The recent 4 weeks of the hemispheric circulation eddy was rather decoupled from the La Nina base-line expectation, as noted by CPC's recent MJO weekly publications - although last week they surmised it may "RE" couple, based on the RMM 3-6 migration being in constructive interference with La Nina..etc. This latter may still happen...and that may start tipping the extended PNA back downward in time - we'll see... But, the point of this verbal journey is to demo that there might be some competing forces in play that make a warm out look less confident. In the dailies, there's deeply gelid air mass plumes still loading into the Canadian shield in all guidance... that's typically a "silent -EPO" tendency. That index actually has a longer term negative correlation coef. wrt to the PNA so having it be out of phase signals the conflict.

I wouldn't call it, "This storm is coming back," with the ominous opening sentence tone, though - that's a bit of a Ralph Phillips take on matters LOL. This snow is not really tied directly into the storm mechanics itself - I mentioned that same exact aspect last night ... In some ways, it seems we have an ANA that is actually ANA-ing. Ha... or maybe if in the quasi sense. There's also a strong and getting stronger, 300 mb jet that's paralleling the EC. In fact by this evening.. it's reoriented in such a way that the strongest winds ( approaching 180 mph!) are leaving New England. I think that is helping blossom this stripe. It was in erstwhile guidance and put some valid question into the mix as to whether more QPF should be striped/banded back west ...which seems to be doing well per rad and sfc obs. The NAM dropping it at 06z is odd. It failed already so whatever... but, these mechanical metrics were still on that particular run. If we negate that run, the NAM seemed to be more correct with placement. It's hard to tell but later tonight the operational GFS appears to evolve a very weak NORLAN? I see a weak IVT with a classic hook in the QPF. I also wonder if that may benefit from a brief window where the llv flow orientation brings OES enhancing into the convergence axis. Interesting...

Uptown never said it’s ALL going to melt. reading comprehension ftl

We had some funny nicknames for him back in the 90’s

Not a difficult feat for model with a typical NW bias ... altho, admittedly, it typically expresses that more often > 48 hours, still - it's not really setting well with me that it is the farthest NW. I've described that bias more than a handful of times. It seem folks are not adopting much awareness ... I suspect because of situations similar to this here, where they need it's NW bias to keep hope alive? Relative to the guidance, nonetheless: The blossoming of that QPF appears almost entirely driven by a very powerful 300mb wind max which accelerates, and situates an axis extending from the interior MA to Maine/NS... close to 180 mph! The entire I-95 corridor in that NAM run is under it's lateral exit/entrance region, ... too far away NW to be directly attributed to the frontal wave escaping off the low mid Atlantic - I think others mentioned this. Anyway, it excites upward vertical motion parallel, and associated elevated frontogenic banding from the DC to Boston. The GFS has the same 300 mb jet structuring... but opts to tilt the QPF axis more ESE keeping lift axis' S of SNE in that guidance. Not sure which is right ... I suspect there is enough agreement among all runs to have that band, and it fits the synoptic argument described above... but the GFS is obviously deliberately engineered to always be the less fun run jeez The whole thing looks like an attempt at ANA like mechanics really to me. Little leery of that... for like ANA ...they tend to be hotly QPF'ed, but end up eaten alive by dry air and slant-wise undercutting NVA/DVM .. taking water mass out of the lower thickness intervals. It may do that here, and prove that band is there ...aloft. It would not shock me if a lot of that is a raging virga shield. But, ..ugh.. that's not all of it. There's likely to be some OES activity given that high's orientation, and the fresh new polar -arctic hybrid air flowing long shore into the coast early Monday. That could be an add on. In fact, the QPF looks suspiciously like the GFS is attempting to upslope against the Monadnocks and lower Whites ... which if is real, would be doing that over ORH too

heh, sorry - I guess I read a page earlier this morning and it came across a bit like a meme buy-in motif where crowd physics drives the weather more so than cloud physics lol. I gotta bop out for little bit. Will let the 18z's cycle in ... maybe some other Meso options will back this look - I dunno - maybe this'll be a quasi posi bust.

heh... new NAM's layin' 2-3" at Logan... I'd go look at the thread but it's an annoying eye-roller delusional hall of smoke and hope in there so I'll defer