Typhoon Tip

Suppression, kind of is negative interference… But yeah, either way we look at it

In fact it would harm matters

The majority don’t appear to have this right, anyway. There is no SSW.... there never was yet. There may be one about Dec 7 or so... but antecedent to the -WPO/ -D(EPO) that was not the case. This is a ridging that is emerging from mid to upper troposphere and the tropopausal heights are elevated around the N arc of the ridge at upper levels; that does have an effect on the morphology of the PV. As I explained the other day, it may be splitting hairs? Either way, a -WPO/-EPO arc can arrive into that scenario however it does, when it gets into that mode, we load ... cold air in the winter. The cold you noted in Canada ( 2-meter temp anomalies... and 850...etc), that is a direct result of the activated loading pattern. This is just -WPO/-EPO, nothing else. Not sure why social media can't help itself but go from 0 to sci fi drama with such little excuse to do so - sometimes I suspect it's society dopamine plague since we've become tech zombies. How's that for sci fi. jesus As far as the colder pattern, this is all greater confidence than people are letting on - a lot of which I suspect is not having patience. Part of the problem of visualizing these changes at long leads ... ( over 15 days in some case...), about 5 days in waiting all the doubts start happening ... People expect to see things now. Meanwhile, models will come in and out of the signal ( operational versions). By the way, here's the 360hr 10 hPa GFS prog... this is a warm intrusion - we'll see if it's real.

Fell for the bait ... after 20 something years of this pastime, too

You're a lost soul to the realm you were meant to roam. Utqiagvik calls to you. The sun just set at that location and won't rise again until January 22nd.

Definitely a colder complexion returned to the guidance overnight. There were some odd solutions there for a couple cycles when considering the principle component/indexes. Likely it was just typical pattern change guidance games all along. We see this going the other way in April where the indexes suggest the season's first big warm up ... but then the GFS wanders off in a spontaneous pita-flop day dream in the other direction. So in this situation .. I'm wondering if we might end up in a split flow type during those first couple of weeks of Dec. There's likely to verify that large scale -WPO/-EPO changing of the guard over the Pacific, but there's been some persistence in the various ensemble clusters to pin the geopotential anomalies along 120 W. Typically that results in flow bifurcation over the Pac NW, with the N resulting stream being a cold loader flow spanning across Canada, while the S branch meanders through the S Rockies... This can be good for overrunning storm types. If the blocking features lose latitude if/where they set up ...that may trigger more +PNA response underneath than we are presently seeing - whole different ball game. But the idea here is a seasonal dump ( we'll see if all this results in more as the times near) of polar-arctic cold at least down to 40 N across the Continent. As far as particularly dailies and what storms form, if/where those do or not... etc etc... too vague for the time being to make much of any play call.

Shhhhh My internal monologue sarcastically said something similar when I saw that run... But it looked less coherent with the EPO aspects... it's like it dropped below the threshold ( probably in error by doing so - ) where it's no longer forcing down stream over the continent by being too weak. That's why it has semblances of the NE Pac mode but dwindles. Goes without saying .. we don't sweat it beyond D7.

That's an ugly Euro run... It's also a fantastic continuity break for a span of time outside of D7 so meh. But it's attempting a -EPO with zero discernible pattern implications for S of 40 N across the continent. that'd be a neat trick.

26 here already

That’s always possible in fast flow but those look spaced reasonably well. It also helps that they’re both flat waves and probably more middling intensity

I don’t understand what the big deal is with the Epstein files anyway… you’re not gonna be seeing the real ones anyway. The only reason why there’s any kind of impetus to release those files finally is because they’re finally done redacting them – obviously

It's more the 29th ... but yeah. It's too low confidence to know about track and amplitude - the latter's probably too strong in this run though. Might be the first multi-region/full synoptic event of the season; don't need it to be heading for the 980s in order to do it. This is open wave NJ model low. They can bomb so we can't through the idea away entirely, but given to the progressive nature ... a middling system fits better.

Fwiw or not ... I'm not a big fan of the MJO unless it's in constructive interference with the WPO mode...or it has a tough time propagating convection out of the marine subcontinent. It has to do that or there's no latent heat flux --> dispersion forcing to the modulate the subtropical coupling to the mid latitudes ..etc. Right now, the RMM shows the wave struggling on the 6 wave number region, probably also because it's negatively interfering with the W. Pac/La Nina. To me that's like a "predictive firewall" ... we'll see what happens if that wave collapse tendency is real. If it is not, then the way may indeed escape the W. Pac gauntlet later in 7 ... The 7 composite is actually a cool anomaly from the NP-GL-NE regions... and then it would be in positive interference in the Americas in 8-1-2. So it's like a yes-no-yin-yang- neg-pos along this wave's progression. I figure the WPO/EPO signal is precedent (there first) ...the MJO arriving late is liable to get damp some. The question is ... does it punch through. I'm aware the RMM has it going nuts in some of the guidance types way out there in late 7. The MJO is not a pattern forcer... it's a pattern modulator. And the latter depends on the whether neg or pos interference. It needs to be positive

But again ... it's may be splitting hairs. If there's -WPO/-EPO through other means, you're ending up in the same consequence.

That's about right.... it takes about 20 days ( three weeks)... I've shown this before but here. This example was 2004. Text book high altitude intrusion event, then nodal mass down welling with 3 or so week lag prior to AO forcing/'blocking' This example actually first became evident over Xmas week prior to Jan 1 ... and the AO crashed by the 20th.

the other clue ... if this pattern change, which we're at t-minus 6 or 7 days from actively reconstructing, was preceded and ultimately coupled to a canonical SSW, the latter would have taken place by the first week of the month. There was nothing...

I don't like the fact that it isn't (first) emergent in the 10 hpa ... This appears to be up-welling from a very strong constructive interference at mid and upper level troposphere between Asia and the N. Pacific. I'm not sure it matters? ha. I mean, whether it's a SSW --> down-welling in the canonical sense and total behavior, or... some sort of fantastic ridge resonance that's bulging the disk from the bottom, the end result may end up with the same consequence... You get blocking and jet distributions S of normal PV latitudes ...and that in this case (sometimes it affects/offloads in Europe/Eurasia preferentially) modeled to favor our side of the hemisphere for a cold mass delivery/jet. It's an interesting question... but if you look at the GFS's 10hpa, no clue there's a warming event. All SSWs in the monitoring history going back to the late 1970s start between 1 and 10hpa, and then down well. This appears to be a "bulging" event. Similar to what Kevin lacks on his anniversary nights...

I've noted the two pulse -EPO behavior in the ensembles. The operation Euro is an amplified outlier with the warm-roll back in between those episodes/-EPO bursts. I'm not inclined to believe it is necessarily correct. The other aspect I'd keep in mind that the models (all of them) tend to go a bit too amplified in the mid-sized spatial events. Not sure that dependable bias expresses as coherently at hemispheric scale ... just something to keep an eye on.

12z oper GFS's 29th NJ model impacter should not be summarily tossed... Not saying it's high confidence - how could I ... But typically the front side wave spaces, while major hemispheric mode changes are underway, are cyclogen active. In principle ...the period of time is okay for activation of storm systems. Way too early to be detailed beyond...

yeah, 19 here. Saturday bottomed out around 29. As I passed by ponds en route to disk golf I noticed ice had crept out about 4 to 6' from the shores, so thin it was gone by early afternoon. Hadn't seen that in recent autumns (I'm the type of nerd that noticed little details like that). Recent Novembers hadn't provided for that intermediate stage in inland ice, but this year hearkens back to that. I didn't venture out this morning but I'm sure at 19 there was probably more than just shore ice.

And then after that, I'm trying to figure out when/if the operational runs start unleashing the goods. With that massive -WPO relay into a -D(EPO) going on at the end of next week, so far it's just a castrated gorilla cold wave ... Yeah, I've been cautioning folks that we may not have to wait until the 2nd week of Dec for something wintry to break in our favor given the modalities from about bird day+ We've benefited ( though the actual daily anomalies may only vaguely show - ) from a -NAO pulsation in the foreground and will continue to do so, then relay that index' collapse into the NE Pac changes. That's not quite the same circumstance as going from a neutral field to a -EPO. This latter tends send the southerly gale up the coast but we're idiosyncratically different when there's antecedent west limbed -NAO.

39/20 in full sun ... it's a winter atmosphere today at least. If there were a snow pack in situ and upstream, we'd probably be stuck closer to freezing.

Looks to me (at this time and based upon recent guidance metrics together with knowledge/history) like we spend a week in a warm anomaly due to the initial shock of negative EPO burst sending a negative implosion down 110 W, but then as typical… natural progression of events will have that spreading east and south as the long wave re-lengthens - that times during the first week on Dec. If things go according to plan, then an introduction of winter probabilities in the first week of December isn’t ridiculous

Warm up out ahead of the continental crash ... right on schedule. Question is, how much so. The amplitude can vary on that. But just in principle, it's not unexpected. The climatology for going from +(WPO/EPO) --> -(WPO/EPO) causes a large scale 'seesaw' down stream over N/A. Heights first crash down the spine of the Rockies ~ latitudes in response to upstream initial ridge blossoming. Some of which is non-linear - which means forcing you cannot see ( longer popsicle headache). But that initial reconstruction is not a stable wave structure at large scales. Eventually the wave length opens up and the eastern end of the -(WPO/-EPO) ... becomes more neutral EPO/+PNA... and the cold then floods throughout Canada, spilling in either a big course load, or a series of dumps into the NP-Lakes-NE... This all trengthens the b-c ambience from Colorado to the M/A, whence winter storms form... Hint: the WPO remains in negative ... that's your seed for reloads. Or not...sometimes all of this is a one time deal. Sometimes you get Feb 2015's of 1977s at the other end and more persistence. Anyway, this is probably what's always caused the Indian Summers throughout history. It's probably what caused the January thaws, too. But they are not sustainable; the above described typical progression of events elucidates why those kinds of 'intermission warmups' prove transient. You know, ... it's all a bit like tsunamis behavior. First the shore water retreats seaward, aka Indian Summers ... January thaws... etc, then it comes surging back and over compensates in the other direction: winter expresses.

The changes as we get past the Giggedy holiday are top latitude down ... The -WPO/-EPO totality is a big dawg hemispheric reordering. It actually originates from the the retrograde of the NAO across the Canadian archipelago ... to reposition into the Siberian-Alaska arc. That evolution drills a negative teleconnector down the Spine of the Rockies, first. This causes an upward height burst over eastern continental mid latitudes. - the Euro is too dramatic with that. - the GFS looks suspiciously like not enough. Obviously this is all waaaaaay the fuck out at the temporal event horizon ... beyond which there be dragons! Buuuut, at a base climate/statistical level, if these teleconnector prognostics are correct with the higher latitude blocking reconstruction taking place, turning warm for 2 or even 5 days whatever over eastern N/A mid latitudes is solid fit. It's a matter of how much or little.