Model discussion: Hunt for cold - into mid-January

[Uncertainty]

There is sadly little true support for the 6z even in the GEFS despite lots of decent topplers helping to enhance the mean ridge placement. I can’t find any other model which creates a cut off GH at all around day 6-9

At 168, I would argue that the S Greenland / Icelandic high is indeed ‘cut off’ on the 6z with low pressure undercutting it from beneath and an unmistakable Omega pattern to the jet stream profile.

 

Would be some victory for the GFS…

[northwestsnow]

Guys ..

I want GFS 6Z to come off too but please bare in mind UKMO 6Z disagreed at t48.

Hey gfs might trump ukmo at day two, but I seriously doubt it.. 

[Alexis]

51 minutes ago, Purga said:

Decent support for the Op 06z GFS so far with the short ENS (incl. the Control).

Yes, in no way an outlier. Almost three quarters of members in support.

[mulzy]

ECM 6z (out to 90 hours) similar to its 0z run and nowhere near as amplified as the 6z GFS.

[Ali1977]

2 minutes ago, northwestsnow said:

Guys ..

I want GFS 6Z to come off too but please bare in mind UKMO 6Z disagreed at t48.

Hey gfs might trump ukmo at day two, but I seriously doubt it.. 

I agree, but maybe the new data brings the UKMO and ECM towards the GFS with at least the chance of a 1or 2 day cold spell. We’ll find out in about 3.5 hrs - then no doubt be disappointed!! 
If the wording doesn’t chance on the METO update I defo won’t be holding my breath! 

[Cold Winter Night]

Meanwhile, as GFS is partying, the EPS 0z is the dullest ensemble I've seen in a while.

The regime chart shows the ensemble going negative NAO first, some Greenland blocking to be expected, but where it had more members going BLO- (Scandinavian trough) yesterday, today it shows a slight tendency later on to go BLO+ and clusters reveal that it has more UK/Northwest Europe blocking). That could mean High pressure dominance for a while, but also allows some Scandinavian High building, as some GFS runs (not 6z of course) have done in the last few days.

The 192h-240h clusters show a High that is too close to us to for us to profit cold wise. The smallest cluster lowers heights over Europe, but that too, with the Atlantic ridge too close.

It's visible on the De Bilt plume as well: Nothing exciting, no support for GFS/GEFS craziness.

So all in all:

ECM/EPS: Mehhh.
GFS/GEFS: Wow!

Let's hope GFS found the secret key this time. Model watching could use an astonishing big turnaround.

[Trom]

1 hour ago, TSNWK said:

Key is the changes are very early at day 4.  So with range of ukm 96 and 120 thus afternoon which should be rated highly in my book.   

Yes at T84 (3.5 days) the uncertainty/volatility in the ensembles increases significantly over the NE US and Canada.  That volatility transitions into Greenland around day 6.

[Uncertainty]

NOT ONE 0z Mogreps member supports the GFS. Across all modelling It’s a huge outlier. 
 

I do believe it’s possible but if I had to make a forecast I’d have to go for the U.K. high as you can clearly see above on the postage stamps which are fully representative of every other model besides the 6z gfs. 
 

I think all of you would do the above too but we are hunting and this run is for me a perfect exemplar of why this thread exists as really we’re talking about one bizarre, disconcordant run but it’s so much more fun than drearying on about flat pancakes, fog factors and to what extent winter is eternally over.

Edited January 11, 2022 by Uncertainy

[Battleground Snow]

7 minutes ago, mulzy said:

ECM 6z (out to 90 hours) similar to its 0z run and nowhere near as amplified as the 6z GFS.

Does the mid Atlantic low look like it will cut off? Appreciate it will be hard to tell as only goes to 90 hours, key period is around 114

[mulzy]

1 minute ago, Battleground Snow said:

Does the mid Atlantic low look like it will cut off? Appreciate it will be hard to tell as only goes to 90 hours, key period is around 114

Hard to say but it’s more of an entity on the 6z than the 0z.  Does that increase the chance of it being cutoff? Maybe…

[Purga]

The Control run would end the month very nicely thank you..

The SE would do very well out of that setup

[bluearmy]

15 minutes ago, mulzy said:

ECM 6z (out to 90 hours) similar to its 0z run and nowhere near as amplified as the 6z GFS.

Spoilsport ……

[phil nw.]

I did post yesterday evening not to dismiss the 12z gfs run but I didn't expect this.

You can never discount short term changes with the trop vortex stretched and segmented plus  the uncertainty of the lows developing over N.A.

Even it doesn't evolve quite as good as the 06z It does raise the hopes of some type of Arctic incursion next week.

[BLAST FROM THE PAST]

1 hour ago, Yarmy said:

 

I checked that a few years ago and it wasn't true: the 4 runs have virtually identical verification stats. 

However, it's hugely unlikely to be correct. ALL the other models are sinking the HP into Europe. It'll be gone in 6 hours or so.

It’s only the initial HP that sinks into Europe and quickly, so that isn’t an issue as more ridging quickly builds in the Atlantic.  The general movement for me for the rest of the month is for the HP cell to migrate W /NW, with deep troughing to east.  The outcome is plausible, but is the timing?

 

BFTP 

[chapmanslade]

The difference at 144h between the ECM and GFS 06z is one of positioning. There is a strong northerly blast on both but on the ECM and 00z GFS it goes about 500 miles further east into N Europe, whereas the 06zGFS has it hitting the UK. Fine margins and all that. Not saying either is right but certainly some interest.

[Nick2373]

4 hours ago, Catacol said:

The azores ridge is certainly poised to enjoy - at least according to the models - its upcoming trip to France. The ensembles do seem to have shifted the emphasis away from the mid atlantic to the continent which for us means a significant shift in weather type. Gone will be options for polar north westerlies, and instead we get a context that will make forecasting specific areas of fog/frost/mirk/mild a tough ask. Much less emphasis on rain. One thing that will be certain if the ridge does get glued to France - we won't see snow. As ever with the UK - small shifts in the locations of a block make huge differences to the surface conditions, and of all surface conditions snow is the hardest for us to find.

Have people spotted articles coming out about lightning strikes over the pole? Twice many in the last 12 months as the previous 9 years combined according to a report in the Independent. Evidence of more moist and unstable air over the arctic than we have had before. With changes like this ongoing, and happening swiftly, I am more convinced than ever that analogues of past winters are becoming redundant. Variations in global weather, and in our UK weather, look certain to continue and grow apace. Extremes more frequent. And for the snow hopers on here like me, that means at some point in some year in the short to medium term we will land a winter extreme such as we had in 2018 again..

Yes it seems so Catacol, but as I alidade to this morning what a flip, now is it going to be there in 4hrs?

[TSNWK]

22 minutes ago, Uncertainy said:

NOT ONE 0z Mogreps member supports the GFS. Across all modelling It’s a huge outlier. 
 

I do believe it’s possible but if I had to make a forecast I’d have to go for the U.K. high as you can clearly see above on the postage stamps which are fully representative of every other model besides the 6z gfs. 
 

I think all of you would do the above too but we are hunting and this run is for me a perfect exemplar of why this thread exists as really we’re talking about one bizarre, disconcordant run but it’s so much more fun than drearying on about flat pancakes, fog factors and to what extent winter is eternally over.

Shame and along with 06z ECM not appearing to support 06z GFS our  hopes that 06z was picking up on new data are dashed somewhat..  

[legritter]

Hi gang ,yes the wording from exeter will be a clue to what is or not lurking out at 168 hrs or so .And then we have ECM Tonight ,hopefully we will see the  high pull back west ,allowing low pressure to dive south or south east, with high pressure then pulling north , all so frustrating at the moment .lets hope something is coming our way in about a week ,i looked at gfs first this morning, my mood turned happy ,then clicked on Ecm ,what a horror chart .so lets just adjust our moods and all say ,its only January the 11th , coffee now for me ,maybe tonight Stella's all round and a grand Ecm run ,cheers gang .

[Roger J Smith]

As BFTP was saying, cold is probably coming at some point but this 06z run looks like it may be overdone. Large changes also appeared with storm tracks on the east coast of the U.S., at about the same time scale. The model has clearly picked up some retrograde signal over the Atlantic, but this model run essentially brings on two weeks of bitter cold where temperatures could be 5 to 8 deg below normal. That would be some turnaround from the record highs to start the month. Could be there's some validity to the idea of colder but maybe not this sustained. Which might raise the chances of snow because despite all the cold air in this model run, snow would not be all that widespread away from a few locations near the east coast. 

[Yarmy]

1 hour ago, Spah1 said:

Not according to Marco

Overall, there is slightly less data on the 6z/18z, but from certain specific sources there is actually more data. For example, the 18z gets more upper air satellite sensor data on average than any of the other runs and that's obviously an extremely important source of data.

Moreover, the 18z will be initialised from the T6 output of the 12z anyway, so it's already used the data that went into that run.

Edited January 11, 2022 by Yarmy

[CoxR]

do the American and Canadian models have similar biases? I've noticed so far this winter they've tended to lead us on in similar ways at similar points in time before eventually dropping the ideas - first december cold spell, then potential blizzard for the southern half of the country and now this 

[Anthony Burden]

High as I stated in my blog this morning with high pressure repositioning several times over or to the west northwest 

the very cold Arctic/ continental air can find it’s way over the U.K GFS has shown this scenario several times,will

it happen it certainly is more than possible.

[GSP]

23 minutes ago, chapmanslade said:

The difference at 144h between the ECM and GFS 06z is one of positioning. There is a strong northerly blast on both but on the ECM and 00z GFS it goes about 500 miles further east into N Europe, whereas the 06zGFS has it hitting the UK. Fine margins and all that. Not saying either is right but certainly some interest.

Quite often, the outcome ends up being something in the middle of the two. Certainly there’s a bit more interest this morning, and a little more to hold onto.

Edited January 11, 2022 by GSP

[Ali1977]

Is the ECM 06z short range behind a paywall?

[Updated_Weather]

On 11/01/2022 at 13:21, Ali1977 said:

Is the ECM 06z short range behind a paywall?

Yes believe it is.