Pattern Changing: Early December threats?

[CoastalWx]

Yeah its further SE with that redeveloper. There definitely has been some signs that it may try to dig just a bit. Obviously we have a lot of time before we can really discuss any of the deterministic solutions seriously, but its a mild interest of note at this point.

Yeah, there has been a subtle trend I think on the ensembles. I definitely feel better about this event for sne as a whole...as compared to this current one and the one for next week. It still might not mean anything for me or the region as a whole, but it would be nice to have part of sne see something.

[CT Rain]

Euro is beginning to like the idea of something more and more around 12/4-5...last night's solution came in a bit cooler and was nearly a miller B redeveloper. Still too far out to really take any use in any deterministic solution though. Who knows what is going to happen with that system. Longer range still continues to feature a somewhat -NAO and a waffling Pacific...might see the EPO go back positive in the long range while GOA back to aleutions lower a bit and PNA goes more near neutral or even slightly positive....but not sure I believe this. PNA going positive on models has tended to be wiped out as we get closer. One thing is for sure, it doesn't look like any shortage of cold air in Canada spilling down.

I think it will be important to watch this in the coming days. Even a neutral PNA could be enough to stunt the SE ridge from really screwing us.

[CT Rain]

Will, do you think the EPO flipping positive is necessarily a bad thing for us? I think popping a +PNA and letting the NAO do its thing is probably more important in moving the storm track southeast because the -PNA/-EPO/-NAO just hasn't been able to weaken the SE ridge enough and has kept the storm track west.

I'm thinking our best shot this time may come from a -NAO/+PNA/+EPO

[Typhoon Tip]

Does anyone want to start a new thread - not to be a douche but it gets cumbersome if one wants to be involved and has to wade through so much ...

It's interesting that while the CPC teleconnector derivations from 00z 26 do not really support these exotic cool downs and storm solutions as is being discussed, the CDC values do - to at least a better degree.

I've mentioned this ... but the CPC derives their values by mid level geopotential anomalies in EOFs; the CDC uses lower tropospheric wind anomalies in theirs. As of last night the CPC shows a neutralizing NAO on the order of some 2+SD intervals, while the CDC shows no such alleviation right out through D13.

Why the disconnect? Why would the lower troposphere not respond as implied by the CDC values, IF the CPC is correct?? That kind of mid level CPC SD correction as implied by the teleconnector rising from -2.5 to nearly -.25 is a large mass field adjustment and the lower troposphere would absolutely have to adjust, and that would thus have to be detectable by the CDC derivative.

You follow me?

I'm wonder if perhaps the explanation might reside with the spatial domains, whether they are different between respective agencies - if so, knowing what those are could be important. Because ... let's suppose the NAO is elevating in the CPC because they have a larger domain that encompasses more of western Europe, and then let's suppose the CDC is more westerly deriving (just speculation): If true a rising CPC NAO might might not reflect exactly how the NAO will affect the western Atlantic Basin because it could mean that the eastern regions of the NAO blocking are compromised, while the western region remains in tact. It could possibly explain a rising CPC and a stead fast negative CDC value difference.

To extend this elsewhere, the PNA is doing the same garsh darn crazy difference between the two. The 00z 26 computation from CPC shows a failed rise in the PNA that falls right back down to -2SD, while contrasting the CDC shows the PNA neutralizing all the way to slight positive between D10 and 13!

So yeah, if the CDC were outright correct, does give plausibility to these recent GFS "lies" - but if the CPC is correct, it would seem the Euro's idea of retarding everything (they put physics in the model that have variable names like, 'f u', 'go to no snow hell'...etc) might ...er, umm. j/k.

anyway... perhaps some hope

[CoastalWx]

John the euro ensembles are probably only slightly negative in the 11-15 day, but everything is very transient. In other words, heights lower in the GOA and then migrate to the west coast, thus dropping the PNA. However, the lower heights then retrograde or redevelop further west in the GOA and this response forces ridging and a slight +PNA. This actually happens twice during the 11-15 day.

[CoastalWx]

LOL at the 12z gfs. The nao block is so strong that it forces and squashes the 12/5 storm. It then develops and merges with another low in the Atlantic and retrogrades towards the Gulf of Maine.

[skierinvermont]

I have a question.. this is a -NAO correct? It just looks absolutely terrible for us, the block is so far south it's basically in the 50/50 position. It seems none of our -NAO blocks have really been in the right locations for us.. sometimes it is too far north or east which allows the 50/50 low to lift to the north and other times it's too far south like this. We just haven't had a -NAO that forces a good 50/50 low (except on 10-15 day model runs last week).

[CoastalWx]

I have a question.. this is a -NAO correct? It just looks absolutely terrible for us, the block is so far south it's basically in the 50/50 position. It seems none of our -NAO blocks have really been in the right locations for us.. sometimes it is too far north or east which allows the 50/50 low to lift to the north and other times it's too far south like this. We just haven't had a -NAO that forces a good 50/50 low (except on 10-15 day model runs last week).

That's not your classic nao block at all. I also think that this time of year (when we are adjusting towards winter), the normal nao configuration that would help us a month from now, can't compete with a deep trough in the west. It's just a little too early for that, but I'd like our chances even a few weeks from now with the pattern we'll have over the next couple of weeks. It wouldn't guarantee snow, but the chances would increase imo.

[Tropopause_Fold]

Well, certainly some tasty solutions in the ensembles over the next 16 days or so. I think we're starting to see some signs of the block having a little more of an influence in the sensible wx as we head into December. While the 12/5 storm could go to waste, I certainly don't have as negative of a feeling as I did with today's storm, or the one coming up for next week.

******DISCLAIMER: THIS IS IN NO WAY A FORECAST FOR HEAVY SNOW.******

i like how it's come to this.

[Typhoon Tip]

Scootage ... you're spot on with that assessment. The Oct-Nov NAO configuration is actually pretty well known to come along with a different pattern and sensible weather than DJFM.

Still, I am wondering if what SK' was after was that the GFS in particular has been hammering the notion of a perfect island postive anomaly more over D. Straight, which coming into the end of November would probably be better for us; however, the GFS has been failing to verify that feature at that location despite the overall detectable -NAO phase state. It's just currently verifying in a poor location, to which I agree.

[ski MRG]

i like how it's come to this.

Yeah, it's totally cool that Scott feels so strongly heavy snow is on the way he capitalized and bolded it. I like that he's not timid and really puts it on the line in assuring us HEAVY SNOW.

[Tropopause_Fold]

have to feel OK about where this is going in the next 10 days.

[ski MRG]

have to feel OK about where this is going in the next 10 days.

Cue the Zuck.

[CoastalWx]

have to feel OK about where this is going in the next 10 days.

Nice weenie solution on the 12z gfs ensembles. Loe pressure gets forced underneath sne, then redevelops se of the 40/70 BM and moves due north. If only it weren't day 10.

Funny thing is, if it weren't for that block and the low well east of sne, the low would probably be forced west of us.

[MaineJayhawk]

Nice weenie solution on the 12z gfs ensembles. Loe pressure gets forced underneath sne, then redevelops se of the 40/70 BM and moves due north. If only it weren't day 10.

Funny thing is, if it weren't for that block and the low well east of sne, the low would probably be forced west of us.

I stress caution on that day 10 prog.

[Damage In Tolland]

Nice weenie solution on the 12z gfs ensembles. Loe pressure gets forced underneath sne, then redevelops se of the 40/70 BM and moves due north. If only it weren't day 10.

Funny thing is, if it weren't for that block and the low well east of sne, the low would probably be forced west of us.

As we thought

[ORH_wxman]

What a bizarre solution on the GFS...the ensembles seem to like it too. We'll see what the euro comes in with in a while.

GFS has a weird blocked up Atlantic pattern with a N ATL block but a low out there too that is just sitting there spinning.

[Alpha5]

What a bizarre solution on the GFS...the ensembles seem to like it too. We'll see what the euro comes in with in a while.

GFS has a weird blocked up Atlantic pattern with a N ATL block but a low out there too that is just sitting there spinning.

What a mess...nonstop blizzard in the Northeast from 210 to nearly 300 hrs. what is the GFS doing

[ORH_wxman]

That's not your classic nao block at all. I also think that this time of year (when we are adjusting towards winter), the normal nao configuration that would help us a month from now, can't compete with a deep trough in the west. It's just a little too early for that, but I'd like our chances even a few weeks from now with the pattern we'll have over the next couple of weeks. It wouldn't guarantee snow, but the chances would increase imo.

Yeah that 144hr map is nothing close to what you normally want to see in the Atlantic in a plains setup like that (just prior to that storm coming in)....Its a glorified west Atlantic ridge, almost acting like a Bermuda high, lol. That things needs to be rotated about 90 degrees counter clockwise to make it useful.

[Baroclinic Zone]

12z GFS Ens advertising a Miller B for 12/5-6.

[ORH_wxman]

Always good to see Wes hint at something...

Not how different the operational models are at that time range over the west and just off the east coast. That should give pause to any getting excited about a 300 hour plus closed low. The ensembles are not saying that such a low is impossible but that there is a tremendous amount of uncertainty. The models so far have been way to aggressive in bringing cold air and snow chances to the east despite the warm advection event for some in PA and nrn NJ yesterday. What might happen after the 7th is an interesting question as the one the models seem to agree on two things, one a strong negative NAO and a strong trough developing off the west coast. The ensembles suggest the euro may be overdoing its trough in the west at 240 hours though they do still show below normal heights in that region so it's not a sure call and the euro ensembles don't like how aggressive the gfs is in bringing its low off the east coast. My guess is that the gfs is too aggressive with that feature. Id be more excited over interior new england beyond 240 hours as the pattern seems to favor some type of miller b event but at such a long time range, it's really too early to make any definitive deterministic forecast even for anyone.

Its going to be a tough pattern because of how blocked up the pattern is on both sides. You have potential EPO blocking and associated PNA trough on one side and a potential NAO type block OR a strange N ATL block with associated cutoff low near it....very nasty for the models to handle.

[snowNH]

Can anyone direct me to a site or post which goes over Miller A and Miller B type storms?

[Tropopause_Fold]

12z euro is not too far from something interesting with that wave/secondary on the front 12/1-12/2. especially for C/NNE.

[CoastalWx]

Can anyone direct me to a site or post which goes over Miller A and Miller B type storms?

Some of it is subjective, but you can probably find some good stuff just by doing a google search.

[CoastalWx]

12z euro is not too far from something interesting with that wave/secondary on the front 12/1-12/2. especially for C/NNE.

Interesting how "blocky" some of these model solutions are becoming.

[Tropopause_Fold]

Interesting how "blocky" some of these model solutions are becoming.

yeah definitely. tough to say how that plays out but it definitely adds an element of interest.

[dryslot]

12z euro is not too far from something interesting with that wave/secondary on the front 12/1-12/2. especially for C/NNE.

Looks like it develops further east and a little colder up here this run..........

[CoastalWx]

yeah definitely. tough to say how that plays out but it definitely adds an element of interest.

I think we'll need that with the Plains monster developing.

[Baroclinic Zone]

Can anyone direct me to a site or post which goes over Miller A and Miller B type storms?

Created a thread for it.

[Tropopause_Fold]

I think we'll need that with the Plains monster developing.

maybe this run will kick it east.