His input is most welcome but I do wish he would post so a fikko like me could understand

So the phrase goes... 'If you can't dazzle them with brilliance, baffle them with BS'  

Well... good support in new EC Monthly by mid-Feb for GloSea5 signal re increased incidence of blocking. Indeed, by week 4, first output we've seen all winter with NO low MSLP anomalies anywhere on the NW Atlantic-European charts. However....where blocking sets-up, if it establishes, is another matter. This was stressed earlier re GloSea5 signal: it MAY lead to colder weather but equally may do opposite. Nonetheless, a growing (if still tentative) bi-model indicator of change eventually afoot

More From Ian on NW

Something about blocking.................but where is anyone's guess

Looks very similar to what Louise Lear was showing for next week

The model output, both at the moment and during the winter generally thus far, hasn't been without interest for cold fans. OK, most of it has not come to fruition as many here (me included) would have hoped, but at least it hasn't been the never-ending mild & zonal dross we saw a year ago.

Wow 18Z really gets the frigid arctic air close! 

A 960mb low over the Baltics must be a tad unusual? I think it's even at 955mb before that - a low that deep in Europe would drag down some fairly chilly air behind it I'd imagine!

Indeed Q, Feb could start quite chilly

Since I haven't had time to make Theta E yet :)

This is a proper arctic air-mass, not some weak 2nd hand polar hand me down. OK to be fair it hasn't hit the UK yet and lies behind a cold front just to the north of shetland, but the point I am making is that to get such cold dry air so far south usually requries an easterly. To get something like this on a northerly is exceptional, even more so if the UK gets hit by it which is far more dubious. 

I believe the lowest thickness on record on a Northerly in the UK occured in the western isles and was 498dm, on the 18Z we have 504dm in Shetland, and if the northerly had not been cut of I'm almost sure the record would have been broken. The potential is still there, its a shame it will probably be not realized. 

Edit: look out for some insane 18z ensembles tonight where the cutoff does not occur. 

Equivalent potential temperature at the 850hpa level. Basically if you take all the moisture in the atmosphere and condense it into a liquid, all the latent heat combined with the ambient temperature results in the theta value. The theta E is superior because it takes into account the moisture of an air-mass rather than just its temperature, consequently it is far easier to spot a front between two air-masses of different characteristics.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

Cohen's update.......................for what it's worth

I thought GloSea5 was suppose to be showing a potential pattern change back in early December i seem to recall? I'm sure something was posted on here from Ian F regarding it.

I have to be honest with the sound of the last part of that post it still seems 50/50 to me.

The vortex displacement to Siberia in the stratosphere in the short to medium term could serve to break down the Canadian vortex in the troposphere and allow some height rises to our NW to start emerging, but it's unclear to what extent such a response will be seen, if much at all.

The MJO might return to strength on another cycle capable of encouraging amplification of the Atlantic flow starting in about a fortnight's time, possibly followed by high latitude blocking establishing, but it's unclear to what extent this will occur, if much at all.

Starting to see a theme here? 

Obviously the MJO situation is more important for weeks 2-3 of February so not worth worrying about for a little while yet... unless, that is, it kicks off on a new amplified (enhanced strength) cycle sooner than anticipated. For what it's worth, the latest ECMF output is basically inconclusive on this matter, while GEFS persists with showing a fairly significant event taking place starting in 12-14 days time.

It seems feb might fulfil its potential indicated by CFS waaaay back in oct/November.

Jonsey- yes I.F. Did indeed call a cold shot & blocking based on Glosea5 early-mid December. Never quite materialised and the signal was quickly gone by the 3rd week.

Control again hinting at something in the NE

If only from the control

Doesn't sound very promising for the UK, though he seems to be expecting the +ve AO to persist for longer than most output shows - the consensus returns it to neutral or positive within a week from today.

He is also assuming weak MJO influence, which may or may not be the case... the wildcard in the pack I suppose. Oddly, he refers to GFS projecting a new event starting in phase 5 to 6 but this hasn't been true for several days now... maybe he forgot to refresh his data source or something. GFS now has a phase 7 start point.

Within the 8-10 day period, we seem as ever to be relying on the vortex over Canada at least losing organisation so that the jet may take on a more NW-SE orientation through the UK, and it then becomes a matter of how much in the way of low heights can get SE of the UK as opposed to sticking around over Canada. Current modelling certainly has the most pronounced transfer of low heights in that direction seen so far this winter, but as with a few quite similar opportunities seen these past few months, there's a risk of that trough lifting out again before any cold conditions can really get established here.

That trough needs to really dig south and become cut-off from the polar jet before I can really get all that interested.
Gooner's posted a good couple of examples to show the sort of thing I mean 

Just for Frustration:

Because I want to be clear this is roughly what I think is going to happen. This is based on experience with the patterns being shown, rather than anything particularly technical or theoretical. Obviously it may not come off. 

Stamp 1:

The first is an approximation to what we might expect at 192hr, Low pressure to the East, high pressure to the west, strong northerly winds provide a brief cold spell especially for the north.

Stamp 2: The block topples, but pressure remains low over scandanavia, a trough develops west of iceland and deepens while moving on a south easterly trajectory

Stamp 3: The trough merges with the scandi low pushing the Azores high to the west. 

Stamp 4: The secondary low looses integrity as it moves south of scotland, once again pressure is kept low to the east, and a northerly develops for the 2nd time, but already a 2nd trough, this time slightly further south is developing in the atlantic, the cold spell is short lived.

Stamp 5: Low pressure moving in from the west while deepening into a rather significant feature before clearing east. A strong cold front will be notable on this feature, this time the azors high is flattened to the south, and merges with a weak area of high pressure in E canada and greenland to form the classic moon shaped HP.

Stamp 6: This northerly is much more stable, with Heights rising in the north, a LP moves against the block challenging it, perhaps we will see yet another reload attempt, perhaps the Atlantic will win or perhaps the block will hold out. 

Bloody hell, I need to get a bigger screen.

So Low Pressure always over Scandinavia!?

Seems pretty clear to me. He is saying that the models are indicating a pattern change, but that the patterns this winter are not following on obviously from the global climate drivers. He goes on to say that this makes the good performance (so far) of the Met's GLOSEA model surprising. 

Nothing too complicated surely?

Yes, I think that is one point which there is very little doubt over. All the models keep heights unusually low in scandi. 

Control and ensemble mean, just a quick sample.