Typhoon Tip

18 Z GFS buckin for a heat wave Monday, Tuesday and Wednesday

Man. ... it's impressive to see now 8 cycles of modeling persist with a 400 mile wide fragile conduit of perfect MDW weather after that two -day scare tactic the models leveled at us the days before ... It's so precarious, yet the continuity is impressive. Keep waiting for the other shoe to fall. Actually, the GGEM operational looks more turd like so maybe once and for all that model can score a coup - heh. anyway, 78 to 85 for three days with sun? -it's actually kind of climatologically unfavorable to do that but it is what it is. It's alright. We'll make up for that over the 4th of July

Nice De Vinci glow

Yeah.. thinking it's time to set the cut off low idea sail because these operational trends are pretty damning to the previous signal. It was always inconsistent anyway...so perhaps not a shocker. Also, as I outlined two days ago, drilling a retro grade cut off from Montreal to Ohio was too unusual to be believable.

Precarious though ... from this range, anyway. 400 miles N or S it gets iffy so it's a bit of a limited room for error there.

I'm privately thinking that whole morass of that is down there, then closing off ... might be over weighted by guidance a bit. The surrounding hemisphere is in an index modal change ... rendering the erstwhile semi-persistent +PNA to a more neutral or even modestly negative one. It's doing this in a matter of mere 2 to 3 days, the speed of which "might" be an issue for the guidance when beyond 4 days away. That index see-saw tries to raise heights in the east below the 50th parallel, while also changing the circulation structure across Canada - the westerlies lift N rather abruptly over the EC ..which is mechanically inducing the models to want to close off that region down there ... But we could be looking at a average of 'coarseness' behavior due to being beyond 4 days... This is how/why the models tend to an amplitude bias in general operations at mid ranges -

Yeah... it's complex. In short, the models are losing the N-stream plunk in crazy retro look ... which fine - that was dubious to begin with. But the southern gunk between the TV and lower Middle Atl region still tries to weakly close off, yet just enough to maybe be a concern approaching from the south without that N-stream nonsense. It's an improvement but not out of the woods entirely. It's possible that southern aspect is also overly weighted by the guidance, but ... of the two scenarios, we don't have a problem with the southern one - there's really not much dubious about that particular aspect. we'll see

48 here... This particular rendition of annoying asshole unseasonable cold loading appears destined to shallow out in latitude ... Doesn't seem the cold 'thick' is cresting the terrain enough, and with d-slope wind and yadda yadda yadda smoke permitting ... still nears 70 down this way, while it may be mid 50s mid summits+ ? up that way somethin' like that. Just gathering my senses on the day ... Looks like a significant shift toward optimism by all operational guidance for the weekend. Friday may be dicey ... early Saturday over Maine, but improves unilaterally by that afternoon, and Sunday and Monday look COL/fair under 12+ 850 and dry-ish ceiling hgt RH levels = 70 to 80+ N-S through the regions. night to day ... Not to push my agenda but I did mention this was possible yesterday. I thought - though - that if we did get this solution to happen, it would take 2 or so days to start manifesting in a grind where the models are clearly deliberately designed to ass bang plans and it is a fight to admit it's nicer. Ha. This did it on the next 2 cycles. Anyway, there's likely to be something down south still that may affect matters later next week - or not... But that idea of severing a 500 mb vortex and then sending it SW from a starting position over Montreal ... to then phase with said gunk in the SE ... ? that was all pretty easily suspect in my mind. Not intending to count eggs before they hatch but as is, we're looking at a rare omelette MDW

Too much smoke

Embarrassingly ... what I just described to PF is pretty close to what the JMA does ... Gets a deep vortex closure as close by as Maine, and than rather than retrograding SW through NY State ( also a red flag in the GFS - ) it gives this by Sunday,

About all we can hope for is this ... ( and it's a real phenomenon in the Spring in particular when it comes to guidance error - ) Once in a while post the bowling season and just before the summer spaghetti heights season ... we go through this period where the models over assess trough closures in that D5-8 range. I've seen this a handful of times over the years, where during modeling pattern see-saw occurrences, they lift heights in the east and sort of don't know what to do with the CU clouds in that region... The models do so too fast and the lower heights ivo the mid Atlantic close off - which turns out to be faux conservation of momentum that the models don't need to conserve. If this is one of those scenarios ... this will begin to fill/morph [probably ] into a weaker mid leve gyre that drifts west over the TV latitudes, while we end up balming out. Kevin is reading this and running to the bank with it - I'm just saying this sort of phenomenon is not unprecedented. It's getting late in the year for the sort of cut off the models are proposing, and while they are proposing it ... there does happen to be a bit of a PNA see-saw in the index, going from positive to negative toward the end of the week. Because of those two considerations... it does remind me of an opportunity for the models to go ahead and exercise that type of error. after thoughts... The models are not going to be good at handling that differential when the surrounding westerlies are in rapid process of abandoning that region of the MA... The trough sweeping SE through Canada is positively tiling - also - at high latitude for that behavior in itself, one that may result from forcing a trough through a region that is developing negative interference. Particularly in the Euro I could see that being a amplitude bias at 144+ hours. So we'll see... it's probably < the 50% probability but it's there. So hope -

Yeah, this interpretive description of her work ( Dr Capotondi's) goes a step deeper into the mechanics of the broader principles I discussed above. The weakening and areal expansion of the HC is going to definitely have an impact on that "...interannual changes...," in terms of both timing and mass-flux of the surface wind distribution in question. No question -

Well .. yeah, there's that too. There's a definite seasonal/circumstantial sort of 'constraint' to this. In autumn, just before the advance of cooling hemispheres reaches the "triggering" latitudes ...yup, those gradients where the Hadley Cell terminates into the westerlies are concomitantly weak. At that time ...circa late August through hgt of the tropical seasons, the HC arrives to its largest perennial extension ( and getting larger due to CC ). Perhaps counter-intuitive, that the spatial increased in that eddy field actually weakens the circulation of the HC ... The region within ends up pock-marked and perforated by more trough meanders and TUTTS, with TC turning right early type behavior. Mind us ...all these peregrinations described are in the sense of tendencies ... El Nino summers obviously do impact TC - or always used to. This isn't even a deep dive into statistical science to bear that out. A straight up linear comparison between cool and warm ENSO ( perhaps yes considering lags, okay ) would demonstrate a correlation. But it has been read that El Nino autumns "shut down" TC genesis earlier than other years. There's also a QBO marker in that discussion that's rather robust. But I wasn't intending to get into TC stuff haha... Anyway, with CC modulating the HC into large spatial arrays and then now having to contend with warming mid latitude oceans ( thermocline discussion notwithstanding/ nor wind ss stressing factors) this does present some problems when considering the gradients overall. I've been arguing this for years. The simplest principle has to be achieved or none of this conversation happens. A has to be differentiable to B. That's why the Universe exists ( lol ) much less the shenanigans of Terrain atmosphere. If A = B ... nothing happens. If A >< B ... forces do everything in their power to get A to = B. This latter aspect is both why the wind blows, and hearts beat. And ... starts the whole discussion about how the ENSO states integrate into the rest of the planetary system.

Or worse for prognostic science yet ... with the present state of background climate forcing, even if one were to predict the ensuing SD to within a reasonable margin of error ... there are deeper questions (valid ones) relating to the integration/dispersion mechanics into the mid latitudes. This is both theoretically questionable, but also empirically suggested too, spanning recent cool and warm ENSO phases, with increasing frequency of occurrences of partial or more complete decoupled states since circa 1998

V-p chart immediate above situates the values somewhere around 90 degrees out of sync wrt to the base-line Walker model. Interesting

Modest anomalies here and there but didn’t appear to stray too far away from a climo rain event

Is that the Taylor Swift show?

Might have to watch for one of these over M Day weekend down there.

I feel like the circulation that opened up and smeared into the gradient was probably on the verge of acquiring …E side llv jet with 65 DPs and a warm metallic feel to the air mass … this was an aborted attempt.

I doubt the Euro cluster works out ... Or, okay - it could if there are changes in the structure of the westerlies between the eastern Pacific and Ontario. As is ... I don't believe we are drilling a -1.5 sigma 500 mb closed vortex SW from a starting position over Montreal and ending up over WV ...taking 5 days to do it.

I'd say by cursory evaluation the GEPs are spectacular, the GEFs are cautionary but not too bad. The EPS cancels plans

We can always hope for the GGEM

Seems like some of the atmospheric pieces to the El Nino puzzle are falling into place before the ocean beneath. STJ S of HA ... Nice b-leaf structure fanning over Texas originating from that feature as it runs up over old Mexico

This is my highest DP of the season at 62 ... despite the quality of the weather, this is actually a seasonal step. heh