Typhoon Tip

True ^ I don't think we've sent a -EPO into a +PNA relay yet this year? The former loads, the latter brings it down. I'm seeing sub -20C's and even a blob of -30C 850s wobbling around up over the Canadian shield every other run over the past couple of weeks There's cold available should the circulation mode stop COC blocking winter This discussion also ( for me ..) hearkens to that other aspect where we don't seem to get seasonal temperature/ "cold" without a direct feeds thing. Meaning, our stasis air masses seem to modulate faster and or just rest state in mid 40s more so these days ... yeah yeah, CC -related most likely. But not looking to start a rage of 'plausible science' retorts that really masquerades as just to hide another form of denialism, either. lol No but more and more ... it seems we don't spend as much time in an average temperature ranges. Either 45 or 15 ..

OH ha... you mean "John" ? I thought you guys knew each other's names but FXWX poster's name is John man I was staring at that trying to figure out what the f you meant by that. Truth be told though ... sometimes it does feel one is speaking to an empty room.

what ?

Anyway, the original ideas for this event are still largely in tact - to me... This appears to be a middling event with ceiling somewhere in moderate amounts ( snow). There may be some subjectivity as to what others feel or want to mean moderate, but less than 10" and > than 4". Should this modulate less(more) in the more certain frames through tomorrow, we cross that bridge. The factors of attenuation were several going into this thing. Whichever is actually causing it to realize thus far, assimilation lapses/speed saturation in the flow/destructive interference aside, we are seeing some of that unfold before our very eyes. The last day and half of runs are taking us through that downward ride. Maybe things have stabilized with these recent UK and Euro type runs in a tentative alliance as of this morning and in fact ...heh. I don't really have a problem with that interpretation for now. I would still caution that we may get significance added back, or taken away further, during these next 3 model cycles today - particularly the 00z run this evening. I will say ...there is some 20 or 30% chance this minors out to the point where it becomes an issue determining what is really causing matters to take place. If the lead S/W runs thin ... yet the spacing shortens with a stronger 2nd, we may burst open an envelopment of lighter regional snows of 1-3" or spot 5" over a span of time anyway. There's also a reasonably good chance that we get something back from the first ... I told John the other day this was going to be a pain in the ass event to track and that much appears to be the best forecast for this f'n thing yet.

Heh. I’m crashin. This isn’t worth it and can’t be up late … good luck.

Actually some identity there at 72 hr We’ll see but guessin it won’t matter. Not enough

Wonder if this’ll be the gone in 2 runs chapter of this. Ha

This run appears to have even less of that backside wind max so far

That much continuity change wrt to the S/W identity, at this range and modeling tech, strikes me as something fishy in the assimilation over the eastern Pacific. Too many S/W in closer succession; the assimilation/interpolation aspects may be splitting the S/W space, given momentum to the lead, giving it away to both the lead and trailing deal on this run. 12z tomorrow this whole mess will be nosing onboard out west. If we're having this discussion tomorrow at this time I'll have less problem with it. That said, this event's governing mechanics were/are susceptible to attenuation for multiple reasons - we've out lined what those all were. Wave spacing is just one of them. Model problems with the speed of the flow and having to accelerate that when mid range nears (robbing from embedded S/W) is another. Now assimilation is also one of those but is different than these other aspects - if that is culprit here, the next run could very well reverse that.

It was vastly different that other guidance wrt to the entire NAO domain handling... Such a wholesale (hemi) continuity disruption is a bit dubious.

I'm noticing that follow-up useless S/W in the TV region is bullying in faster than the other guidance. It appears there's some sensitivity wrt that feature - the models that have a bigger gap between it and the lead Jan 7 S/W, have more intensity with the our storm. Short version, the Euro has more neg wave interference there from the looks of it.

Guys... can you take that to the banter thread ?

yeah... it looks like the -NAO is trying to exert a weee bit earlier than prior depictions. This being 8 days out - obviously goes without saying, a wholesale correction east with that OV trough becomes more penetrative. The whole thing could change into something else. The NAO is a masterful headache inducer. It's seldom correctly handled even at D8. For that matter, it could just up and evolve into an eastern limb expression... sending things to Manitoba. But present trends are the other way so - all possibilities about the flow east of Chi-town are still in the playoff hunt re Jan 10/11

Okay ..sufficed it is to say ( not including the Euro just yet) these 12z blends signal a major snow fall. I.e., something > than the "moderate ceiling" I assessed. However, I'm not ready to sign on just yet - although I really, really appreciate the gesture hahaha Seriously, this hasn't relayed into the physically realized sounding grid out west, and a high speed ... essentially longitude pattern that is at the far eastern end of the Rossby wave coherency ... those are circumstances not well handled by models. It makes events very prone to subtle variations - so prone that even in these more modern/well-advance assimilation technologies, there can be very important nuances introduced when that relay happens that take away(add) to this thing. There's that... but also, the stuff I said about attenuating magnitudes in the models when crossing D5s is still not tested just yet. I'd like to see this tomorrow morning to be more confident that we're getting through the de-amplification two-step. I'm just trying for some objective 'what-can-go-wrong' isms here. I don't think we have to reach very far to grab a hold of those.

It was ... and the 500 mb is significantly colder in g-pot hgts as the wave space compresses through PA than prior runs. ... I mean this thing is still 8 days out -

I read the weekly publications from the MJO desk/NCEP ... They often describe the MJO correlations as being in competing or 'destructive interference' with the "on-going El Nino response" umm

(psst, i think there's a chance that whole system decays into sw flow producer)

wrote about the same exact thing re the 6z ( last page..). It's like comically perfect. It's attempting to model the elusive 'synergistic' event, the one that is supposed to be unknowable and catches everyone by surprise and snows double all leading indicators. haha. Man, what a coup de etat if it succeeds

Repeated the 6 z as far as I can tell ... (I've rejoined work work, though ... so my analysis is cursory)

ICON is basically the perfect way to maximize snow proficiency out of an attenuating ( weakening...) total wave space. That's a weak but still anomalously juiced Miller A response ( initially) that gets captured by a NJ model rapid deepener. I mean if you look at 500 mb, it has a flat wave geometry ... however perfectly aligned in torpedoing along the quintessentially ideal latitude of 1.5 deg S of L.I. for climo frontogenic forcing along the Pike. The end result of all that is that the ICON's 6z solution is attempting to actually forecast synergistic over-achievement. That's probably snowing 3.5"/hr rates for 4 hours between HFD and BED Mass out of a mere neutral standard deviation 500 mb synoptic look, by colliding these metrics. That's impressive for going shopping in a German candy store LOL

George! George! George!

thank you very much!

Well ... I'm not speaking to where the storm actually tracks. That disco above is really just regarding the expansion of the lift (synoptically) .. where those jet fields align implies the area. snowing vs dry air battle notwithstanding

-AO/-NAO ( now include -EPO in that ...), with a -PNA. But also, I checked and the WPO projections are still tanking mid month in all 3 major sources. That's going to transmit the AB phase across the Pacific circulation mode (higher heights N over cooler heights S) and almost invariably that precedes either a +PNA ...or a hybrid -PNA ( 2015 February) I'm actually more optimistic at this point than I have been for a mid winter month in years quite honestly. If this were me 15 years ago on Eastern I'd have started a thread about a potentially cold stormy era lasting 15th to 25th of the month - but popularity for those extended risk assessments has since turned into bundamentalism so I don't bother LOL

One aspect that we less often cover as a group in this engagement are the mid and upper air jet mechanics. But the overlay of the 500 mb and 300mb do indicate at least a somewhat favorable synoptic divergence potential in that layer. There is a fairly strong wind max/arc entrance region exiting Maine as the more mid level exit jet region is approaching L.I.-ish. That gap is a teeny bit larger than ideal... still, it may be close enough to enhance lift over the top of where the 700 mb is forced over the cold conveyor belt. I could see light snow farther N-W due to that "mid and upper air magic" . We're still 5 days away. It's probably more appropriate once we get closer.