bluearmy

Exeter are calling a higher chance than usual of north or east winds as we head towards mid feb. That likely places a block to our nw or north. not particularly specific but possibly reflects an agreement between glosea and ec46 clustering. Whilst the scandi ridge option seemed to catch a few off guard with its appearance within 10 days on modelling earlier last week, the ens suites that pushed that ridge also failed to maintain it and sent lower heights across to scandi as week 2 progressed. I think many here expected to see HLB showing by the end of jan. Some model runs are expanding a monster of a Siberian high end jan but it seems that the upstream tpv will see that off as far as it influencing w europe. It seems that we have to go through the cycle of the tpv sending a chunk to scandi and then we wait to see where the wave break sets up the upper ridge that follows. the seasonals have been fairly bullish on height rises to the wetst or northwest in feb - my take is that many here haven’t seen any reason to dismiss that. We just have to get through another transition of zonal flow which sadly is longer than many hope to see.

Really ?

The extended period in the ens (days 10/16) sees the SPV set up roughly barents/NZ and on a N/S axis having a sceuro trough makes perfect sense as we head through week 3 But will we see the trop making its own music ? Obviously a few recent gfs ops have trended this way but we likely have to wait a good few days to get any confidence on this type of solution (assuming it continues to garner broad op gfs support )

all three ens suites are pretty much on the same page at days 15/16. That should provide some confidence the sceuro trough slowly gaining strength and hopefully the Iberian heights to retrogress nw in week 3 the pieces of the puzzle are there but may not align for us - or they might !

Whilst we continue to look for changes in week 2 guidance, it does seem that the NH profile will continue to bring a fairly zonal n Atlantic out to the second week of feb. The southern half of the U.K. could hang onto the euro ridge a fair amount of the time to keep rainfall totals down a bit but concern that a fairly strong flow could interact with the ebb and flow of the euro high to take us into the second half of the alphabet on named storms

No 46 again trends better with retrogression of the ridge second half feb

If we’re getting an arctic ridge involved again then we can expect fi continuity to drop off significantly …… yeah I know

Not sure what you’re asking but I would urge people to use the wind flow 10hpa charts to judge where the spv is rather than the temps this run makes more sense to me if we are to see the strat and trop vortex remain coupled as has been the case for some time now Having the spv over Barents and an upper scandi ridge wasn’t a recipe that made me comfortable

I assume phase 8 would be post day 16 so won’t show on the three ens suites but the 46 also goes to day 20 so it would seem that phase 8 isn’t before feb 8th at the earliest

Neither are particularly exciting 7 has too many euro heights showing and we know with the same anomoly that the euro heights will be more prominent 6 does at least have some low euro heights which we could manoeuvre around a bit either way we need to get through these phases Joe b was commenting yesterday that he thought we’d miss out 7 and come back in 8

Looking like quite a struggle to get enough amplification on a scandi ridge with the spv likely to be close to Barents/NZ and the tpv Canadian segment looking to extend itself towards that locale. a murr sausage would work and if we could somehow get some lower heights to run clockwise around a ridge with an associated cold pool then that would possibly be the best we could hope for in next 13-16 days. currently ens guidance looks like any scandi height rise likely to be extended to sceuro and followed by an mid Atlantic height rise that draws the euro heights west. again, no indication what amplification may be possible on that but it’s well into week 3 so out of range of ens

Having lauded the 18z it comes up with a pattern which sets alarm bells ringing for me. I hope this is all trop forcing and not something to do with delayed strat reversal waves above 70N which I see as the big risk in feb for getting the cold as far south and west as nw Europe (for example - I mean that’s where our interest lies after all)

The pub run has a bit of the 00z gem about it shove a ridge up and then undercut if so that there are heights around svaalbard waiting for that next push and for good measure, the pub run rotates the Alaskan ridge to try and complete a cross polar ridge!

Reckon will take a few more suites to get a direction of travel. We could end up honing in on a scandi cluster and a mid/east Atlantic one. And I doubt we’d avoid a U.K. mlb cluster on most runs!

Slowest retrogression ever !

Eps control is close to the op at day 10 and evolves in a way that many are expecting with scandi ridge of sorts and a slow move nw thereafter

It was more amplified yesterday to day 8! id expect a decent no of eps members that are going to bring a scandi ridge but this op looks to have decent continuity from the 00z run

Met4 cast has replied along the lines that I would 2013 - memories! Was that the Ukmo day 5 wtf moment? looking back we had an amplified w euro/sceuro ridge in place when the ssw occurred. We then saw a second push north of Atlantic heights which forced a svaalbard upper ridge and the Atlantic then undercut that. So the zonal flow dropped v quickly on the models. I assume that was the quick response. this just seems like the actual ssw is the crescendo of two weeks of reversals and warmings but it’s weak - so it likely doesn’t have an impact. Whether we see downwelling waves in feb from the first half jan warmings is probably something that glosea 6 could be seeing. Not something we get to see other than it’s 1st of the month run at 10hpa. Because this seasons strat is so unusual I wouldn’t make a stab at what mig happen in feb other than I just feel we will be generally frustrated by what transpires.

Its all semantics the ssw is weak and brief. if it isn’t at 60N then it’s at 61N. If it isn’t at 10hpa then it’s at 9hpa. There’s no practical difference. the warmings of the past three weeks have been notable and left their signature through the strat at high latitudes the recent gfs ops have caught my eye as they are showing some stretching of the spv later week 2. The 06z gfs op also began to show a bottom up split that we’ve just seen play out. more uncertainty then if the trop is to continue to lead the dance.

You’d expect any response likely within the next two weeks to now be picked up by the models (especially eps ) as the warmings of the past three weeks are pretty much done nothing solid showing yet although the scandi ridge solution is the most common departure from the norm that we are seeing play out @jules216 - I think you’re in a decent location for weeks 2 and 3. Either a cold trough or a good chance of a hit from a deep cold pool

Yes - Running the frames up to day 15 shows that if it is retrogressive, it will probably take another cycle upstream to force it second week feb is beginning to crop up a bit regarding the current spell of cold and it’s flagging up via various methods the two week cross model ens were rock solid counting down (give ot take a couple of gefs runs that lost the ridging into Greenland ) the ec46 saw the pattern well in advance - four weeks away at least but it had it a week too early to begin with im still intrigued as to what would have evolved if we hadn’t suffered the shortwave system running across the country from Iceland and cutting off the cold flow for at 25/36 hours and indeed, encouraging it to head broadly southwest which brought the lowest heights closer to the Canadian trough. The Azores low would have tracked east at a lower latitude and dragged the troughing way down into France. someone will make the case that we would have seen a strong wedge left griceland that could have disrupted the Atlantic trough on a much further southerly track ….. the macro cannot see the micro such as these shortwaves and how they then manifest themselves. They can have big consequences

Cluster 1 looks like it could be retrogressive with the euro heights ???

This is discussed in the strat thread @purga Whilst there is a split of sorts just about to end (and when it does the Canadian segment rushes east to rejoin and we see the same in the trop ) , the reversal is weak and looks to be more about the displacement of the Asian segment over scandi than due to the split. The current strat trop coupling is strong but there are some gfs ops recently that seem to show something of a disconnect again as we enter feb

Some very interesting NH profiles into week 3 on the gefs

Above average for a short while but not a ragingly strong spv. And then the gefs seem to want to drop it back a little below average by end week 2. The gfs op looks like it wants to stretch it across the pole which could make things interesting if we get a renewed Asian warming. yesterdays ec46 kept it a little a little above average for the next month or so with little sign of any drop off in flow. Centred ne of svaalbard. gefs end week 2 are approx in that ballpark I would agree that this would make a full blown Greenland ridge less likely but we could get a griceland fella with that arrangement. The upper strat pv doesn’t necessarily imprint precisely into the tpv. It’s can often be on an angle whereby the spv could be over svaalbard high up and the tpv w Greenland/ne Canada.