Daniel*

You say that but Northern Europe/Scandinavia is expecting coldest winter since 2009/10. The deep cold has been persistent in upper Europe, potentially accessible to wider Europe things have just not aligned at least yet. Again an illustration in a warming world… persistent cold anomalies can occur regionally. I personally don’t see the value in looking at entire Northern Hemisphere you need to look at areas with relative proximity to UK where the cold originates to our north and east. I don’t see why for example a very warm Canadian winter means much to us.

As said the AO is already on side, I think it’s a good indicator to a quick response. Much less possible interference and the need to break down stubborn +AO.

It’s possible the trop pattern can be already primed and be a catalyst to major SSW and very rapid downwell they are ultimately related. So I would say the ECM 12z is QTR in my opinion.

Well maybe I’m remembering wrong but I’m pretty sure Feb 2018 split looked very similar to this with one shard in NW Russia and other in eastern Canada. Of course 2018 was not the most durable but the issue I don’t believe was TPV it was NAO blocking becoming too west and retrogressing too much… maybe too much free rein is a bad thing. I think we had too much of a good thing then.

Well this is the chart of winter… the split which appears favourable on GFS, is our best shot of getting a significant late winter blast.

Frankly I don’t know what you’re talking about we have been seeing long drawn southwesterly winds from subtropical Atlantic which are much above average waters. The direction has absolutely everything to do with it, as I’ll say again SSTs are near normal to our west if wind blows from west it wouldn’t be excessively mild.

It was warm in 2018 too when extreme cold was seen. February 2018 actually featured record anomalous warmth in Arctic.

A great example of QTR.

What you say is not strictly true actually with 2018 major SSW given the nature of split it was actually quite a long wait. It’s been known for the big SSWs to have impacts within a week, I think this occurred in Jan 2013 there are other examples too like Jan 2009 both splits a week later London saw its biggest snowfall since 1991. The fact the AO indexes are already on side is another indicator of a potential quick downwell before the end of February I’d say.

I think he is actually pointing otherwise, that’s a good signal same happened in February 2018 split I recall, one shard in NW Russia and then the frigid easterlies arrived. The actual vortex lobe itself does not bring cold weather to UK as waters around us significantly moderate it.

Southeasterly a distinction there…

Now you’re really talking.... GFS 12z emphatically splitting polar vortex.

UKMO definitely best of the lot heights going up and over, but I do not trust this model one jot.

Getting sufficient CAA seems uphill task but yes latest GFS much more amplified to NE.

Well major SSW looking increasingly inevitable some GEFS runs dropping it to -20m/s which is impressive and benchmark of a very powerful event. It could be possible we see most significant SSW since February 2018 event but for the moment a split is not clear, it’s hard to see the vortex truly recovering into spring. I think the spring could be eventful this year just a feeling.

On global scale yes but most of “North Atlantic” is not especially relevant to NW Europe at higher latitudes. Vast majority of that anomaly is coming from lower latitudes. Waters to our north, east and west are not unusually warm therefore the idea all wind flows are excessively mild is false. It’s southwest flows which are very mild and even milder.

Hardly inspiring GEFS but another GFS op on top end from start to finish today. Well there is some good agreement at d10 between ECM and GFS ens perhaps chilly rather than cold at the moment but something to work with heights quite strongly signalled to NE. And a gentle continental flow. I haven’t had a frost in a while. Deeper into FI things become more possible with retrogression signal near Greenland EPS been quite persistent with that opens up more possibilities for deeper cold to be introduced. Overall not a terrible direction of travel but it’s not a fast path to glory, an opportunity for regular night frost to cool the ground, dry with sunny spells offering good useable weather. Then we should be more primed for something of more significance… later than we’d like but beggars can’t be choosers.

Well it’s wrong to call it “North Atlantic” when it goes down to latitudes of equator. That is not the North Atlantic it’s all being tangled into one.

Unsure about that the North Atlantic is actually pretty close to 1991-2020 average right now, it was freakishly warm last year. So I wouldn’t expect westerly winds to be much milder. Much above average SSTs are seen in subtropical Atlantic off Iberian peninsula and down to NW Africa, more southerly maritime flows are exceptionally mild. Original post: https://community.netweather.tv/topic/99814-model-output-discussion-22nd-jan-2024-onwards/?do=findComment&comment=5032262

Unsure about that the North Atlantic is actually pretty close to 1991-2020 average right now, it was freakishly warm last year. So I wouldn’t expect westerly winds to be much milder. Much above average SSTs are seen in subtropical Atlantic off Iberian peninsula and down to NW Africa, more southerly maritime flows are exceptionally mild.

Not true..

The refusal of low to ease or drop south is quite something 72hrs > 120hrs, it even goes north it almost appears to go against the laws of physics with rising pressure to northeast. Some of most frustrating output I’ve ever seen.

We really should be seeing better here, at day 3, polar jet deflected well south and yet lows are meandering around our vicinity, sums up our luck this winter though - totally nonexistent.

Little consistency today the earlier GFS runs veered the flow from continent. Faith in NWP reaches rock bottom...

Something not right there with snow line near London uppers are positive.