Typhoon Tip

First GFS run to start nodding toward pattern change ...

19/20's in danger of getting damped right out of existence altogether. it occurs to me, the models with more power in that S/W are taking them west...the ones trying to shear it out are south. Just an observation,.

God I hope so ... I'm just about out of patience with this winter. I can be objective about modeling and trends, and telecons and ferreting out signals and so forth - it's not that. But if these methods and verification alike keep up with this, I'd be more than happy to put it all behind us at an unusual early exit date. Dust off and move on.

wow...what a bomb on that 22nd/23rd ...potentially. That thing bumps east at mid levels by 200 or so miles and that defines the season off any such correction/solution.

I've actually been noticing across all guidance actually. Lately the mid and upper air charts don't lend to very good sfc appeals - but then the surface charts have snow chances. I think the pattern change is real...and the models are just fighting desperately to avoid admitting it. hahaha... No but that's not that uncommon with southern height walls while cold loads to the N. I've seen 10" of snow fall along Rt 2 with 70 F NJ in March. So long as we're in a spring pattern seemingly eternally.. heh

It's an extraordinary run to look at... That 144 through 168 is almost comical. And I'm not even saying it won't happen that way, but at 144 ... you look at the 500 mb isohypses layout out and there is no way the flow across Canada would physically allow a system to cut. So the Euro reconstructs the entire circulation manifold ..thus finding a pathway to do so.

I just also mentioned ...that's the sneaky type of wave that would overproduce. Thinking from memory over the years of modest frontogentically charge mid level collocated over the top of an impressive isentropic lift axis. Nice leaf expansion on sat.. Those can layout a band of S+ that definitely would not be seen at this range.

Significant trend to more suppressed track/Miller B response in this 12z GEF's lends confidence to the operational GFS... GGEM also followed suit re the 20th. I don't have a problem with this, given that it is on the interface of the ... a pattern change that is admittedly in trouble, but we are likely to at least register some +PNAP ...if perhaps with a split flow variety. That combined with a slumping NAO does support a southerly track with that middling S/W ... The event it self might cash in on CC pwat and an over ploduction.ha. either way, riding flat waves over SE ridging can pay off.

Not that anyone asked but I'm on the fence with this early week thing. I have too many experiences in my decades as a troubled, too oft lovelorn partner of weather to allow much excitement for any "western fringe" phenomenon. That's the canvas I start with. But it's not just tainted by personal experience. There is verified examples. The Euro is not unprecedented for proven a west over-zealous solution. It duped NWS back in 2014 I think it was, with an intensifying hook and latter scenario. With just 36 hours preceding ... it puts out a model run backing 18" snow totals and 55 mph wind gust clear to EWR, sending them scrambling. Blizzard warnings, to cut-ins by the Mayor of NYC warning civility ... 1" of dust. It also has an attenuating amplitude bias, moving events from mid range into short term that is perhaps too subtle most of the time to even notice. But we're dealing with 10s of miles delineating not much to a band of light to moderate snow and/or sleety rain.. heh. It might make a difference at that scale of precision. The NAM? I've been telling this forum community that it's got a NW bias between 48 and 84 hours for years.. I did notice the 06Z GFS tickled back west a little more. It's a fair enough statement that there are examples of backing events, too. It seems they happen, but the western extent ? That specific handling aspect is like IVT snow bands in the mid range - seldom does that ever work out as modeled. It'll be interesting... As the adage goes, there's nothing else to feed the d-drip ( not an adage but it should be )..

Not to taint anyone's coolaid but .. this cutting vortex reminds me of a spring/April west Atlantic deal. I've seen that QPF chart many, many times in springs over the decades. And it's always more ominous looking in the charts than what verifies - but we'll see. I could see that being mainly just nasty conditions out side without much else to write home about. The cold is attenuating, and it's whirling over a 50 to 60 oceanic surface down there, so the what's coming off the ocean might not be properly assessing in the runs, either. Just ...I dunno. It's not impressive to me yet. The 500 mb is also filling - btw - during the whole thing.

Y'all realize that's the day 15 and 16 GEFs there? ... either way, that's likely over doing the AO domain. There can be a descent in latitude with SPV, achieving extreme geopotential depths, without that layout over the arc. The Euro's chance for a mix event down to Rt 2 has legs imho ( 20th-ish). The Miller A should be watched on the 22nd

It doesn’t carry a lot of deterministic value but for example… the GFS operational version out there between the 23rd and 26th is a perfect example of what we’re talking about wrt negative EPO type system profile. That’s a decent front end dump of snow followed by glazing scenario for interior Massachusetts with ease on that solution even though the 500 mb doesnt look anything like it would drive that.

I am noticing propensity in the GFS toward a -EPO rendition of pattern modulation... That version does slow the penetration E across the continent with distribution of cyclone track and cold, during the 20 to 26 time frame. The EPS cluster is more +PNA ...getting there quicker, with less obvious positive g-hgt over the Alaska sector. There is room for either version to manifest. Just a word of advice as we tick days closer to a possible if not likely, winter recovering mode for mid latitude continent. Having said that... the EPS might offer hope for winter enthusiasts, sooner, with more commitment to EC. But the GFS version could also perform in overrunning "Minnesota squeeze" type mixy results. I suspect the operational GFS is too extreme, either way. How much or how little -

Mm... the post was not to intended to aver any actionable course correction - just in case You have to specific/qualify a post or there's a tendency to interpret. I figure you know that... But, I was offering a suggestion (plausible) to offer some insight as to why-for some tendencies we are seeing in recent guidance evolution.

no kidding ...? LOL

A GFS flavor would likely result in what Brook's is screaming re the overrunning type messy winter storm structures. The EPS ... what does the UKMET family look like? I bet that might be interesting - but it may not go out far enough? The UKMET loves to curl the flow early, so if it is somehow avoiding the SW tuckies, heh.

Nope - ... not allowed. either George runs the model from his basement ... or bust.

exactly ... And I don't have a problem with it doing that per se. I find it interesting that the GFS wants to force a pattern change toward that variant, where the other's in the playground want the +PNA/PNAP version

It bothers me that the last several cycles of the GFS operational version have/are just about 180 degrees out of sync with the EPS in the 240+ time range, wrt to the 500 mb isohypses layout. It doesn't bother me for deterministic forecasting - per se... But I do feel pretty strongly that a pattern change ...if indeed that takes place, would likely already be exerting between D6 and 10. SO what? is the GFS trying to avoid even changing that pattern?

Definitely more of "burst" appeal to this snow at the moment. Still just 28, but uniform mid sized aggregates with vis down to 1/2 mi. Not looking at radar so as to not taint the experience with reminders LOL

I've been trying to pay more attention to this model ... get a handle on it's usefulness. It's referenced from time to time in NWS afd's, etc. Can't figure it out. It had a backed solution like this 3 days ago... when none other did. Now, the others do, and it won't - okay. Still new to me with this tool though. Actually ..as an afterthought, I do recall there was other suggestions from guidance et al for a second wave/bulging west, but it wasn't done this way. Interesting. I remember posting that I don't typically like the bulge back west scenario in modeling at the time. But this is different in that the low is cut off more fully and waits 24 hours before retro -

It's for symbolism perhaps ...but considering where this winter has been at least out side my doors here in Ayer, seeing it snowing at 28 F is a rare, precious come-by. Well formed small to mid sized dry aggregates, with a couple of degrees to spare no less.

Correct, it is important when evaluating to keep in mind that the magnitude scalar value of total change, is less important than the occurrence change blah blah But this weekend’s more recent emergence in the runs may not be triggered by that NAO … it’s really more a situation of getting caught by it. The ocean cyclone’s set into motion first … then the NAO dumps SDs, and in terms of what that means to the pattern … the.cyclone gets a retrograde momentum applied to it - That appears to be the larger scaled super synopsis. Not a major event. Probably bands rotating in with wet snow cat paws on the Cape with a stripe farther W maybe BOS to PVD and points E.

Re the weekend folks should be aware of this indirect /possible factorization

Walt, it's a personal view ...but I suspect it ...and the 19th/20th ..et al, trending very recently, may be transitively related to the pattern change. Noting the deep layer tropospheric circulation mode over much of central and northern Asia is changing from a westerly predominating flow to a north, in as little as 48 hours! That sends a robust signal down stream and resets the dial across the Pac... Not sure why the GFS has been resisting, but the 0z GEF mean resumed... I don't believe a progressive/native GFS bias is well suited for where the hemisphere is heading post the 20th... so that's negotiable. But the GGEM and Euro are already pressing a latitude ridge signal into western continent by the end of their runs ... The ocean storm in the foreground may be a coincidence, but it actually fits where the hemisphere will be about a week later - fascinating.