EasternLI

Euro weeklies, so grain of salt of course, but that's one large weakening trend for the strat PV in one run. Seeing Ural ridging now perhaps. Big jump there. 

Last run 

new run 

Regarding the Pacific jet. Watch the following loop. It begins with a -EAMT. This wants to retract the Pacific jet. Which it does, as you can see the Aleutians low retrograding closer to Russia. The problem is, there's a massive +EAMT event rapidly approaching right after that. So the Pacific jet is re-extended, wasting no time. I believe this is what is driving matters out there that we're seeing on ensembles lately. 

This seems to be driven by the re-emerging Urals block that's been gaining traction on ensembles recently. As those have been linked to Siberian high pressure episodes. A Urals block could lead towards a strat PV split, if that continues trending with the state of affairs being set in motion in the Pacific already. That's in addition to what I mentioned with the jet. 

Just pointing out some important features when they present themselves as good enough examples on current guidance. To be clear, there is no SSW modeled currently on any guidance. There is only some warming being modeled with some distortion currently. That is, however, highly dependent upon how the 500mb plays out. So I will continue watching these matters including the Pacific. With that Urals blocking possibility being a relatively new development also now.

Some big picture thoughts;

So, it's been roughly 5 days since I posted anything. Just watching the runs since then trying to gain ideas on what is being shown with the progression. There are some key things to be aware of in my estimation. 

First, I'm not really sure that the MJO is even a large factor in what is happening this time. I think it has a lot more to do with the Pacific jet being extended. Which could be driving that signal instead. However, that is also one favorable condition for mjo propagation, so its a bit unclear. Regardless, as it retracts, it's driving the wave breakers in the Pacific. There could be some positive feedback to this process from the PV dipping west of the Aleutians. I could see that as a possibility. This seems to be doing a couple of things in addition to whatever occurs over the CONUS. It should still offer up some +PNA, but there's more at work here which I will show. This is just the gfs jet for example, don't take literally. 

Secondly, there was a very informative tweet thread by Jason Furtado earlier this week. Pertaining to the stratosphere and these Pacific wave breaks.

I do believe we're actually seeing both of these things he described occurring on guidance since then, in a way. The following loop is the 06z gefs for example. I think the wave reflection is playing a role with the consistently higher heights being shown in Canada, firstly. While the Pacific slowly retrogrades underneath that as was previously brought up. 

In addition, he mentioned that the waves could break in the stratosphere instead as a second option. Causing warming there. Which is what I was referencing in my last post about that subject. Which was simply an effort in pointing out the chance of doing so.

Since then, guidance has been actually trending towards a couple warming waves now up there. 1st one is weak and starts this week, but its followed up by more, which are increasing in strength in succession. So this will warrant continued monitoring moving forward. 

Now, clearly, nothing specifically can be inferred from any of this at this time. This is more an effort to point out some important factors worthy of consideration. I will just be continuing to monitor trends for the time being. I suspect predictability confidence will remain rather low with everything going on moving forward. It is a lot on the plate for modeling. Especially if/when the stratosphere does start seeing some sort of action on top of it.

We're just all along for the ride at this point. However there is very interesting scenery remaining, if one digs deeper. Hopefully it can come together favorably. Whatever transpires will have ramifications on later January and how February will go, I suspect. Just felt like offering up some food for thought for the new year. In addition to some reasoning on why I just cannot turn my back on this winter. At least not yet. 

Cheers. 

The series of wave breakers previously discussed is still progressing well on ensembles guidance. The western cyclonic break and eastern ridge break are now seen well on ensembles, to the point of being represented with the opposite signed wave following them now. Meanwhile the wave breakers in the Pacific associated with the retrograding vortex are progressing towards an Aleutian low. This should all allow some +PNA to take shape following week 1. Here's how that's looking on the eps. However the gefs isn't really that different either. 

These same Pacific wave breaks, as they occur, are sending heat flux up into the stratosphere. It's a known area for doing so. Hence my no pain no gain comments. Guidance has started picking this up as well. There's definitely a realistic possibility of some action up there. As well as some more promising prospects for winter here, for hopefully a more extended period if we play our cards right. It will be very interesting to me to see what happens. I'll be watching the trends with everything. The situation may seem hopeless currently. But it's far from that IMHO. 

30 minutes ago, EastonSN+ said:

Emerging in 8?

Not emerging. Progressing through the Pacific 6,7,8. The circle is the 1 standard deviation demarcation. Which is significant in la nina. It's complicated though, those charts belong in the dumpster IMO lol. They can be misleading sometimes. 

9 hours ago, brooklynwx99 said:

we are going to torch through the first week of January

however, there is increasing confidence that the Pacific jet will retract after this timeframe. this will push the ULL over AK back to the Aleutians, likely allowing for a strong -EPO/+PNA to develop, similar to what we're seeing now. you can actually see the poleward wave breaking at 200mb. pretty good signal

blocking isn't showing its hand on the ensembles yet, but blocking in Jan is quite likely given how blocky this month was. the persistent negative anomalies in the Atlantic also point towards its development

so, we're going to have a reprieve, but it should be only that. winter may return in earnest around the 10th or so... Arctic flow would make Canada cold very quickly, and we're in peak climo at that point

Agree. I've been watching this and was going to post something, but you nailed it. You can now see the series of wave breaks as the vortex retrogrades. We even see the ridge breaking in the east now too. With the tropical signal headed through 6,7,8. I'd consider it to be a likely progression at that. But just to add on, I mentioned no pain no gain with the AK vortex in a previous post and that is a good loop now.

So as that feature retrogrades back to the sea of Okhotsk. You start to crank up the heat in the strat as well. Which is what we like to see. This is also in accordance with the tropical signal. This is a situation that is nothing major yet, but will definitely have to be watched as there is real support for consequences up higher. Merry Christmas. 

26 minutes ago, MJO812 said:

Wow buffalo

https://buffalowebcam.com/live-webcams/buffalo-ny-elmwood-ave-mr-pizza

Their forecasted snow amounts have been raised to 48-60 inches .

I once lived down the block from that for a time, years ago. This is a huge one for that area. It's much more typically further south that get the heavy bands. This is more right into the metro area and nuts with the wind.

We're at the mercy of wave breaks going through the next 2 weeks. And models do horribly with these, as we know. The ensembles are illustrating it well in the loops. This is gefs, but eps looks fairly similar to me with the features. 1st one is the cutter wave break which is then replaced with a ridge in the east. But also note the ridge break in the west which is replaced with a trough. Meanwhile the Alaskan low is retrograding west. 

Looking just beyond that. You can see the trough then breaking in the west. And the vortex continues to slowly retrograde. Therefore, there's reason to believe in some renewed western ridging after the upcoming warmup. In addition, by that time, the tropical signal is poised to help out with that as well. This will need to play out, because exactly where these waves break will determine what happens. All models have a hard time with this beyond a few days, and ensembles are smoothing everything over due to member spread. All hope is not as lost as it may seem attm. 

It sucks we're missing a big one, sure. It is what it is, not everything works out. We move on. We monitor. Because these wave breaks are also reinforcement to that northern blocking that keeps hanging around also.

2 minutes ago, Allsnow said:

What happens in Okhotsk? 

Strat vortex shots. Need a Scandinavian ridge to finish the job next. But should allow PNA also. Tropical signal supports it.

No pain, no gain with the vortex passing Alaska. It needs to get into the sea of Okhotsk for my purposes, and it's on its way. It will not stay parked on Alaska for a month. 

I felt like digging into the cutter situation and how the situation changed so drastically in short order a bit more. So looking at it from a bigger picture perspective. I can offer an alternative cause. A very ill timed cyclonic wave break, for our interests, is identified. With the lobe originally forecast to set up at 50/50 on guidance now going to break instead of doing that.

I know some are, but many may not be aware. When rossby waves break, they immediately are then replaced with a wave of the opposite sign. So that means a trough would be replaced with a ridge and vice versa. You can see the lobe break, and immediately be replaced by the ridge in the following loop. Therefore, cutter. 

As a side note, there will be a ridge in the east after the cutter cyclonicly breaks. It's one main reason why things often flip right after monumental events. More breaks to come according to ensembles. I think quite a different picture is very capable of emerging on ensembles as we head through this week actually. 

I'm far from sold on an extended warmup. 

2 minutes ago, MJO812 said:

Euro looks interesting after the cutter.  A storm chance ?

 

Blocking continues

Nah, everyone shut the blinds already 

Really difficult to get a read on the extended right now IMO. When you have a mean that looks like this. However within that mean, the #1 cluster from the cluster analysis is a different idea than the mean would lead you to believe. It's really going to depend upon how upcoming wave breaks play out. Tricky timeframe. 

56 minutes ago, Rjay said:

I wouldn't blame him if he never posted in this subforum again.  I'm close to it.  

20 minutes ago, EastonSN+ said:

While the ensembles continue to vary on the PAC progression, all continue the blocking straight through.

Right. And these wave breaks help reinforce it. So I think it matters what happens with this week as well. 

If you loop the ensembles, you can see a CWB cyclonic wave break near Alaska. And the trough retrograding back towards the sea of Okhotsk. But need to see how this week plays out first I think. 

1 minute ago, LibertyBell said:

Not detecting the record warm pool in the Atlantic in the midrange to long range might be the answer.  The models seem to lock in on it only when we're within 7 days.

 

There very well could be a feedback process from that. It's possible. 

2 minutes ago, LibertyBell said:

What caused the change?

 

Really hard to say. The models have been trying to figure out what to do with complicated features. In the 2 areas that are most difficult for them. North Pacific and arctic. It's like an honors exam for guidance.

Gefs being stubborn with a cluster of offshore lows. IDK what happens with this thing. Not crazy about the orientation of this block now. It's changed quite a bit in a couple days. Who knows. 

1 minute ago, EastonSN+ said:

This winter may end up being something really special.

It's got a shot. That's why I cut the punter from my team this year in November lol. We'll see how it goes. No issues for me just yet. Looking good.

Oh man, this is really nice!

Big time Aleutian low paired with big time Scandinavian ridge is looking very stout indeed. The strat vortex is going to be facing big big trouble...

1 minute ago, Nibor said:

 

That there is about as tasty as it comes. 

More chances to come too. This is the first real chance lol. Right on time too, if you ask me. With winter just beginning on the 21st. Met winter is just for bookkeeping IMO. This is playing out nicely. We may need to make some stops for pickups.