Typhoon Tip

no one's asked me buuut, personally, confidence in any seasonal modeling is lower than even the usual eye-rolling when the model being use has "climate" baked into it's title and/or physical make-up.

Ah... well, if he's gotten it accepted by whatever peer reviewal process is required for operational/official usage than it is what it is... but who knows - Personally I have a handful indexes that are Johnisms haha

"Snow Advance Index" ...interesting... never heard of that particular index. Is that his? - guess I'll look it up If it exists it'll be interesting to know what goes into it. Like is it 2ndarily based upon the AO ... +AO is the cold index state in the Arctic domain... whereas the negative phase is actually warm at high latitudes. I've long suspected this season may observe an aggressive recovery take place at some point along the way... perhaps both land snow and sea ice for that matter ... The AO has been demonstratively positive really since the end of summer. Meanwhile, the ongoing prognostics from CPC keep correcting outlooks positive so ...it appears to be a really basal/systemic aspect and not just a ephemeral mode tendency... Having said all that... I think there's been papered work published in recency that upended the Siberian snow cover assumption - perhaps not entirely but lowers confidence in using that metric as a predictor. I'll have to see if that's true still. It was originally studied that cold/cryospheric genesis, aids in colder lower troposphere, which then lowers heights - and that raises hgt at mid levels due to restoring in the total column. That

my opinion is that the +IOD and the +ENSO are all a part of the same super structure, exposed by observing the totality of the Walker construct. - whether aware or not... when evaluating either we are just in a quadrature (tranche) of that whole structure. The DVM tendencies over the eastern limb ( ^ ) of the +IOD mode is actually the western limb of the DVM associated with the Pacific Walker circulation. and so forth... The reason I see that distinction as important is because ... particularly in this incredibly wholesale immense +ENSO planetary state, there's likely to be less ability for permutations in the IOD domain to really mean anything because that region is subsumed by the whole/thus indicative of that larger magnitude. I don't think it is adding or "boosting" in this case...? Given to the above totality, it's already integrated already added in/accounting for in other words. But it does offer an intriguing idea after the fact ... that integration may create secondary feedbacks (synergistic amplitudes in either positive or negative direction).

.. there's historic data that suggests warm ENSO autumns frame cyclonic tendency in that region along and off the middle Atlantic. This year really hitting that with panache. There really wasn't much of an input in terms of arriving S/W mechanics into that region leading into that thing. There was only weak sauce arrival prior to the one at the end of September, either ... that made major media outlets millions on pimped out headlines... My hypothesis is that it is the CAG climo repositioning up and off the eastern seaboard - 'CAG' referring to the Central American Gyre... It's a general region of cyclonic tendencies that formulates in late summers and throughout autumns, situated as the naming suggests... around the western Caribbean/adjacent. Anyway, this is a source of 'home grown' TCs in the October climatology for west Atlantic Basin activity. Fronts or frontal echoes decaying through the Gulf can also formulate 'book end' spins but ... overlapping general vorticity potential in the area is an overall culture jelly. The CAG is there because of overall large scale Coriolis balancing underneath autumn high pressure settling through the TX. My hunch is that the large hemispheric circulation mode/manifold, indirectly related to the warm ENSO, favors this more off the EC than down there in typology. We have a high pressure seemingly eternally lodged and incapable of settling S of us - see current sfc analysis' - which has been there for days. When it breaks down... no worries. Another dying cool boundary wafts silently trough, and reinvigorates the high pressure all over again... and this is causing a standard weakness over/off the M/A just like the CAG machinery. interesting...

agreed... I mean probably - Here's the thing ( though ) ENSO may not be effective in the hemispheric pattern modulation until the seasonal gradient steepens enough to trigger that forcing. I've explained this in the past ...whether necessary to do so or not ( hey, that's how I roll! ), that it's not enough merely having these teleconnectors on the map. They need to be effective, more importantly ...how to know when/if that is the case. The way they become effecting is through gradient. That is the metric that decides. It goes back to fundamental physics. IF A > B, A --> B That's how all nature works. Period. If that one fundamental universal aspect were not always the case in the cosmological perpetuity and infinity there would be no restoring force anywhere, and everything would stop. A must be greater than B, in order for that action of A on B to take place. So why that is important here. The amount of A had to be significant (enough) bigger than B (gradient) before the "-->" starts happening. Synergy explodes out of "-->" This, to the clever reader, is why RONI is both very necessary and works. Because B is climate change and it is a +D(B) factor. So.. the A growth has to grow even more to trigger the same "-->" Can't be explained any easier... This ENSO is certainly a warm pig, but .. the world is a bigger warm hog right now. So, as eye-popping as this El Nino is, it is not entirely clear that it is operating/forcing on the system yet due to this over all arithmetic. And so if it is not yet doing so, there is no synergy. The synergy would be later on when seasonal/hemispheric gradient gets sufficient and ubiquitous.

yup ... ... There's a synergistic potential there, too - adding a third, the -PDO hangover ... whereby three dominate modes, working together, produce more impact than scalar sum of their input. What makes that trickier than the typical unknown quotient of synergistic result, is that one of these modes is new, and "newing" - in other words, a changing input. It really takes the unknowable synergy, and makes it extra double top secret unknowable. Ha It's tough tho... Folks need to philosophically understand that "more impact" does not mean more scalar amplitude. It can... but impact in the context of ENSO pertains to 'how much does it force the system' - and by that, deviates it from a non-ENSO base. A base that now is D(CC) ... see where this is going? I mean it doesn't mean higher wind gusts and deeper floods, nor satisfying one's snow lusts .. A valid interpretation of these can simply mean more pervasive ...lasting longer ..etc. If NYC go 120" of snow this winter and never snowed more than 8" in a single dose, that would/could likely be a synergistic improvement on just having an El Nino, or CC working alone with a -PDO hangover. 8" is actually manageable. Or... it could mean two consecutive yard-stick bombs totaling a National Guard deployment, sure. Part of the problem for those setting up expectations off El Nino dividends, or subtractions, either way, is that El Nino is not a weather forecast. ...obviously there are those of us that are aware of that but you'd be surprised... heh

Incredible temperature variance due to cold drainage this particular morning... Cold drain and uneven distribution by dawn isn't in and of itself very unusual, but varying 20 F over short distances, is. It is occurring among a lot of the non-standard NWS sites in the interior. ORH was 43 for a low, now 52... Same in Sterling and N. FIT ... yet, it's 31F at the Oxbow site along Rt 2... Interesting Some of these chillier sites are likely to see a 20 to 25 F bounce this morning.

There it is ... the new climate normal for snow in October

looks like yet another NINO 3.4 spike has take place... ~+3.2C now.

yeah... I was just remarking about this over the ENSO thread this morning. It's anomalously cold relative to pattern - which is interesting ... if one can keep personal druthers out of the perspectives. We've observed a trough scooting quickly through Ontario a couple of times, but by and large ... we've been above normal hydrostats over much of the CONUS below the 45th parallel, yet ... we are getting frost and freeze headlines and lows in the upper 20s. -the longer term temperature anomaly distribution still probably end up decimals warmer than normal. That's been a leitmotif going back ... years actually. We end up above normal against the 30 year base while being below normal relative to daily metrics like the pattern. It's like we've been getting "cheated" from realizing a stunningly warm October along 80W over the continent, stunningly warm a lot of months, due to "pinch low" phenomenon and/or sneaky llv cool inserts, despite the fact that a truer polar branch of the westerlies (jet) has been situating N-W. It's interesting that we just cannot seem to sustain a westerly lower tropospheric momentum under this July setting ... like in Julys either! This whilst frost advisories underneath ...

SSW's may be challenged more so than climatology this season. Hard to say ...some competing signals... Pro: there is an apparently ( assuming so ) a modeled switch into the westerly QBO phase pretty quickly this autumn. W-QBO correlates to a easterly momentum inject into the stratospheric altitudes. It's like warm advection currents dissipating at higher altitudes capture/drags some of that momentum then intrudes it into the PV ... and helps the wave break/ SSW phenomenon. Con: however, this has been a very active solar disk spring/summer/ and continues here in autumn. These solar 'storms' break apart ozone in the high altitudes. UV loading related... Ozone is the primary conductance in getting warm intrusions to 'flash' through the higher PV column.

Likely related ... ... for one, although the sample size is not appreciably large ( on the order of 10 or 12 spanning 200 years ), of those warm ENSO, something like 9 or 10 had these autumn hybrid like circulations. Not meaning to say that is what's going on down there at this time, but... you know, if you're going to hybridize a gyre in that region, you wanna start with something like the theme we are in fact seeing so far ( the unusual end September coastal event that was over publicized (snark) being a fair example). Some guidance couldn't resist and bored that thing down to almost 970 mb.. as it were ... it was just a pedestrian. But still very really and albeit asynchronous low - one which happens to fit the total idea. We are still in the correlation window so this weakness/tendency for another low there ... it's suggestive enough. It's important to note however, El Ninos do not directly cause storm or no storm formation.

Yeah...maybe. Don't know. Parsing out the momentum like that over years - that's harder ( at least for me ) to balance sheet that because circulation modes get seasonally mutilated by winter and summer for one. But, the 2023 spring planetary temperature explosion phenomenon is super-climatological in nature and really appears to have taken place mutually exclusive of the ENSO cycling. We need to bear in mind that the sea system and the atmospheric system, en masse, burst .5 C upward in all dimensions, all at once. That in and of itself is still not very satisfyingly explained ...though there are some compelling ideas. sure. But anyway, that took place prior to the end of a cool ENSO, and a couple months before the onset of an ... interim warm phase that frankly I feel was some sort of "absorption event" to try and eat that heat and didn't reflect a truer Nino atmospheric circulation mode outside of the immediate tropics...maybe lower subtropical bands... but that's farmer John's supposition. Anyway, detonating an entire planet like that doesn't lend to stable predictions.

Yup ... and I realize we've been over this aspect before. But these signals don't turn an entire planetary system on it's head that quickly. There's momentum stored in the other mode and takes time to move away. It's sort of analogous to a seasonal change ... ex, we don't observe Aug 15 --> Nov 15 on a straight 45 deg downward angular trajectory. It goes back and forth while accumulating the lower height state over that span... in theory. We can always count on a complete systemic rollback to July 15th on Xmas Eve! So, as we go from a cool-->warm(vice versa) ENSO state, the atmosphere will tend to a kind of 'non-Markovian' echo of the form mode. It complicates matters further these days when/since previous modes became increasingly more disrupted ..heh. However, in this case since the -PDO is significantly correlated to the -ENSO, and the PDO is really a reflection of the longer term SS wind stressing in the quasi-coupling of the air-sea environment out there (therefore, atmospheric mode-), there's decent enough confidence that we actually had an NINA hemisphere last winter.