oasis

Thank you Interitus, Knocker and Singularity for taking the time to respond to me. I greatly appreciate it. I dont have the links to the data and analogs at hand/the necessary knowledge so cheers. Looks very interesting Singularity, curious how each decade has had slightly different patterns regionally. Certainly to my untrained eye does look like in general the temperature gradient between polar and mid latitudes has become stronger in our region of the world than in North America. Hence greater mobility in the Atlantic sector. Amy Butler's tweet offers some reassurance though.

Question: Does anyone know if the average u wind speed of the stratospheric vortex in winter has been increasing over the past 30 years? I know the stratosphere has been getting colder, so I wonder if this is encouraging a trend towards a stronger stratospheric vortex, and our winters experiencing less northern blocking/cold weather. Or is it that the stratospheric/troposphere vortex is just becoming stronger specifically in the Greenland area? As a result of some other forcing such as the omnipresent NE Pacific ridge? It seems, at least anecdotally, that North America has continued to see similar amounts of arctic outbreaks from the vortex breaking down in the past 30 years.

Hello. Yes, it does seem a bit higher, though not by a massive amount. Also, from what I've read recently, the amount of ice is still very low on our side of the Arctic. So, around Svalbard etc. So I'm not sure that this increased amount will have much effect on autumnal/winter weather patterns. Ie, to keep on topic, charts for the next week have the jet stream passing just to the north of Scotland and leaving the south of England untouched. Which could be linked to lack of sea ice.

Curious, ICON looked a lot better for coldies with the low pressure earlier in run, and then later on marginally so.

ICON at +60 has the low pressure in the Atlantic further south. Not sure if that's a good sign. Though high pressure migrating quicker west towards Greenland. For coldies do we want the high pressure to migrate slower towards Greenland?

Thanks. Yeah, I guess with ECM and UKMO on board as well you'd expect the overwhelming majority to be correct. In a more zonal situation 19/22 would normally prevail.. And as you point out, even on those runs where a northerly sets up you still get some of an easterly in the south.

What do you think of the couple of ensembles which drag high pressure quickly to Greenland? Noise? Or still potentially a signal to be aware of?

To my eye there are still a couple of GFS 18z ensembles which quickly take the high pressure to greenland and rapidly cut off the easterly flow from the deep cold pool. I think related to @bluearmy's shortwave point earlier. So, hopefully from a coldie perspective that cluster goes from 10% to 0% tomorrow. They are still cold though.

The more of a straight southerly flow into the arctic, the higher latitude the high pressure will establish itself. If there is a bit of jet energy pushing east like on the ECM, then the high pressure will establish further south. Though if it too much energy goes east then obviously the high will completely collapse. Hopefully the latter won't happen, and at least some part of the UK gets pasted. And at +168 on ECM we see a sub -20 cold pool setting up in Poland waiting to be advected westwards.

I think UKMO would potentially be better for those living further north, due to its higher position, while ECM would potentially be better for southeners. A la GEM, sub -15 uppers and all that. Of course the run is still to complete, but seems it could set up that way.

ECM 96 seems better than GFS 96. Though not knowledgeable enough to know how it will turn out. Less intense vortex south of Greenland, stronger high pressure over Scandinavia. Seems kinda similar to ICON.

It would be nice from a coldie's perspective if that was the case. I think someone said it's the biggest stratospheric reversal in many, many years. With all that cold pooling on the models to the north east seems -10 850 temperatures with day time maxes no higher than 3 or 4 degrees are almost guaranteed if the jet energy can dive south. And as mentioned that's the very peak if the sun comes out, from 12pm till 4pm.

Just a thought, but could the higher resolution of the good models ops actually be lowering their accuracy at this moment in time? Maybe the operationals are picking up in more detail other parts of the climate system like GWO and MJO, parts which are against mega extensive blocking, thus diluting higher blocking in them, while the lower resolution runs are not able to pick up so much detail on the MJO/GWO and are instead more purely reacting to the overwhelming stratospheric signal? Hence more extensive northerly blocking in the lower resolution runs and the lower resolution models? Would anyone know if the higher resolution runs are more higher resolution relative to lower resolutions runs in the strat or with regards to tropical feedbacks? @chionomaniac @Steve Murr @bluearmy @Catacol Plus anyone else interested who could answer my question.

I saw mentioned about lack of stratopsheric tropospheric coupling in near future, suppose if these charts can happen, that would mean upper vortex not filtering down?

Is this the right place to put this? Jason Furtado suggesting lack of stratospheric troposphere coupling in foreseeable future, which I think means tropospheric weather patterns can run their course without intereference from the stratosphere. Good news for cold weather fans if current long range forecasts continue as they are. Ie, strengthening vortex won't cause problems from above.