Model Output Discussion - New Year and Beyond

[summer blizzard]

32 minutes ago, The Enforcer said:

Now that is stretching my memory, but given my recollection is that the end of November 2010 was already polar continental, all GFS had to do there was maintain the status quo. Here, it has to hold onto a pattern change. If my memory is wrong, then one victory in 13 years doesn't inspire confidence.

Correct. As I recall the models picked up on the low going south around the 10th (so basically from day 10) and then just stuck with it (the low sat around and the cold arrived on the 24th).

[alexisj9]

Now later on GFS twelve z is an outlier on the 850s.

However it isn't when the high first starts, so could well be placement or shape. This is in Kent. Also quite a few members do visit the same area in different times. We'll see I guess. Wondering on the 18z now. Will it still be there.

 

 

 

[Singularity]

Quite puzzling that while the GEFS 12z shifted substantially toward recent GFS runs, the EPS 12z hardly budged, despite the det. run doing so and the control run being along similar lines as of day ten.

Something's off somewhere. Either EPS are seriously underplaying the MJO influence relative to stratospheric, or the other modelling is overplaying it big time.

[Johnp]

Oh dear - a much flatter 18z run so far up to day 8. 

[frosty ground]

1 minute ago, Johnp said:

Oh dear - a much flatter 18z run so far up to date 8. 

Chalk and cheese 

[Allseasons-Si]

4 minutes ago, Johnp said:

Oh dear - a much flatter 18z run so far up to day 8. 

 

3 minutes ago, frosty ground said:

Chalk and cheese 

It's one run and the pub run at that and besides,...it's not flat just less amplified.

[Nick F]

Intensely deep core of the TPV drifting too far east across southern Greenland to allow heights to build north towards the Norwegian Sea on the 18z. But think it's overdoing the depth of the TPV and it's been very volatile run to run over where it moves over and between north Canada and Greenland. Once the models settle on that and the troughing disrupting or not to our east, then perhaps the models will settle on a mid-lat high over UK or ridging further N then NE for Scandi high.

Edited January 26, 2023 by Nick F

[alexisj9]

5 minutes ago, Nick F said:

Intensely deep core of the TPV drifting too far east across southern Greenland to allow heights to build north towards the Norwegian Sea on the 18z. But think it's overdoing the depth of the TPV and it's been very volatile run to run over where it moves over and between north Canada and Greenland. Once the models settle on that and the troughing disrupting or not to our east, then we perhaps the models will settle on a mid-lat high over UK or ridging further N then NE for Scandi high.

Other difference, the low that goes down under the high, in this one goes round over the top and cuts it off, so we are back to a UK high. That one low seems to be the difference.

[Allseasons-Si]

One thing of note is the latest gfs drops lower heights quicker into central Europe and the Med further south by day ten than the 12z,...swings on roundabouts but the general pattern remains the same,...a foothold in this pattern looks likely than the atlantic onslaught it showed a couple of days ago.

[Eagle Eye]

Quoting myself from a few days ago;

"The expansion of the Atlantic high pressure cell is looking fairly likely and that may mean that we end up under a fairly dry spell through considering how close we could be to the easterly low pressure we may still see a retraction of the high pressure to allow a cold/snowy spell to return though what I think is more likely is that we stay fairly dry compared to what we have been but cloudy and around average temperatures. Beyond that and the exiting Wave is likely to retrogress the high pressure and that may cause the slow progression back towards the +VE TNH pattern but at this range it's hard to tell what way that will lean in terms of the high pressure regression. The retrograde Scandi-Ural high will be an interesting one to watch for surface warmth developments over Scandinavia and the displacement of the cold as that'll affect where the cold is centred, interesting for gaining cold from different areas such as the South."

Was caught out by the model trend. Was expecting the relative development of a dry spell, what was not expecting was the movement towards a UK-Scandi high and possible cold through the back door though I did briefly mention it. Still think it's unlikely to be well amplified but chance is increasing despite the relative 18Z wobble...

12Z as an example.

[Nick F]

The Balkans and Greece cold and snow lovers will be happy with day 10 from 18z GFS.

[Allseasons-Si]

15 minutes ago, Nick F said:

The Balkans and Greece cold and snow lovers will be happy with day 10 from 18z GFS.

I see lots of wriggle room with this scenario if this pattern is set,..much to be resolved on a microscale though but liking the macro pattern.

the gfs is similar around Iceland in fl with the retrogrssion,...another fl teaser on the way

it has been consistant of late,...ops look to lead the way with the control in second place is the way i see it and the ens following eventually.

Edited January 26, 2023 by Allseasons-si
typo

[alexisj9]

3 minutes ago, Allseasons-si said:

I see lots of wriggle room with this scenario if this pattern is set,..much to be resolved on a microscale though but liking the macro pattern.

I'm wondering where the ensembles are this time.

[Don]

16 minutes ago, Nick F said:

The Balkans and Greece cold and snow lovers will be happy with day 10 from 18z GFS.

They often are these days!!

[Polar Maritime]

Maybe even a named storm?

 

 

[Allseasons-Si]

8 minutes ago, alexisj9 said:

I'm wondering where the ensembles are this time.

I am not staying up for them,time to hit the pillow shortly....sadly

another interesting set of runs today promptly switching to a Scandi high around day ten as apposed to an atlantic unsettled onslaught,a drying out is most welcome,...hopefully followed by a seasoned start to Feb with a colder spell,...i would take that and gives me a chance to get in the garden and sort a few things out that i couldn't do with it raining most if the time

G'night all and here's to a cold Feb,...hopefully.

 

always watching the back door :)

 

Edited January 26, 2023 by Allseasons-si

[summer blizzard]

43 minutes ago, Singularity said:

Quite puzzling that while the GEFS 12z shifted substantially toward recent GFS runs, the EPS 12z hardly budged, despite the det. run doing so and the control run being along similar lines as of day ten.

Something's off somewhere. Either EPS are seriously underplaying the MJO influence relative to stratospheric, or the other modelling is overplaying it big time.

When I looked at the MJO charts yesterday for same date of both. Euro went straight for phase 7 but was weak and probably turning back to the COD while GFS was moving through an amplified phase 5-6-7 as I recall. 

Would be interesting to see when last we had both an amplified phase 2-3 and 6-7.

Edited January 26, 2023 by summer blizzard

[Paul_1978]

48 minutes ago, Johnp said:

Oh dear - a much flatter 18z run so far up to day 8. 

Nothing interesting has been on the cards before day 8 on any model anyway. GFS turning out alright in the end. We need to reel these decent charts in with a rod and line!

[alexisj9]

2 minutes ago, Paul_1978 said:

Nothing interesting has been on the cards before day 8 on any model anyway. GFS turning out alright in the end. We need to reel these decent charts in with a rod and line!

Let's hope tomorrow the start is in day seven 

[geordiekev]

1 hour ago, Johnp said:

Oh dear - a much flatter 18z run so far up to day 8. 

Looks pretty similar to previous run up to day 8. The retrogression in FI different but hardly unexpected 

Edited January 26, 2023 by geordiekev

[The Enforcer]

1 hour ago, alexisj9 said:

Other difference, the low that goes down under the high, in this one goes round over the top and cuts it off, so we are back to a UK high. That one low seems to be the difference.

Models come up with a decent pattern and depth of cold, but only at range, then play a variant of 'Whack-a-Mole', called 'Whack-a-Shortwave', where we all try to guess where and when the previously unmodelled spoiler shortwave will appear.

Edited January 26, 2023 by The Enforcer

[alexisj9]

3 minutes ago, The Enforcer said:

Models come up with a decent pattern and depth of cold, but only at range, then play a variant of 'Whack-a-Mole', called 'Whack-a-Shortwave', where we all try to guess where and when the spoiler shortwave will appear.

It was very favourable until now lol. We'll see. It's the thin one the goes up and over this run, last run it went down and developed under the high, to prop it up. 

Edited January 26, 2023 by alexisj9

[Cheshire Freeze]

4 hours ago, Uncertainty said:

Last night we were staring at a period of oblivion - and a very well signposted one at that. As I’ve stated before I’ve had U.K. high —> westerlies —> big block is the progression. But I expected the middle phase to last into the 2nd third of Feb. 

The ecm last night was just about as bad as it gets.

The 12z gfs op last night was completely and utterly on its own. A shining light of hope in an otherwise barren sea of desolate output. 

And yet, tonight, the gfs op (again), GEM and  EC Ops are suggesting an amplified U.K. high - and not one that looks like flattening quickly either. The ensembles aren’t there yet, but have trended in that direction. 

So why the shift? And will it be gone in the morning?

The mjo seems keener to stick in high amp phase 3, I’ve always found p4 promotes flat westerlies in winter. The Paul roundy regressions for Mid Feb are really really interesting, but don’t necessarily explain the present shift.

Could it be the strat? Perhaps - a bit early for a QTR. I don’t know. The strat pattern doesn’t scream exactly trop easterlies though. But what I do know is that if the zonal winds were v strong or strengthening, the block would be far less likely.

I’m very wary of this change. It is incredibly rare to go from this:

To this:

 

But what I do know is: I know which one I’d prefer!

 

 

It’s no coincidence is it…we saw zonal winds increase later December and the rot set in, we’ve seen the zonal winds decrease and again we’ve seen a pattern change.

Some people were adamant there was no coupling but it’s too coincidental for there not to be IMO.

[alexisj9]

It the little wave going over the high here.

 

[northwestsnow]

GFS drops any notion of a block..

GEM kind of keeps the faith.

We need a good EC.