Model Output Discussion - 1st - 7th January

[WhiteFox]

More than 1% of the UK's population lives north of Stirling, places such as Dundee, Inverness, Perth, Aberdeen, Stornoway - you've heard of them all because people live up here and we do count I'm afraid!

Dundee isn't northern Scotland though. Even if you include Aberdeen and Dundee, the population of the cities mentioned is 400k. Stornaway only has 9k, and the other Scottish Islands aren't exactly heavily populated. It's not intended to be a dig at northern Scotland as I think it's beautiful, but the fact is that the areas forecast to be hit by blizzards are very sparsely populated compared to the rest of the UK (including southern Scotland).

[chionomaniac]

Sorry to hear that OON. Regrettably I'm struggling to see anything positive for cold in current model outputs, but I'll stop posting now until something appears.

It's a pity that you can't see signs of a change, Shed. I would have thought that with your experience you too could be picking out the clues that are being demonstrated hemispherically and in the ensembles.

Getting back to Steve Murrs point on a suspected pattern change, it was never going to be a quick one. Sadly, without a dramatic SSW the troposphere has been drip fed slow stratospheric mean wind changes and will continue to be so for the foreseeable future. It is akin to sitting in a bath with a leaking plug - the water is slowly going down but it is not noticeable at first. Then all of a sudden one realises that they are sitting in far less bath water than previous. The same is occurring with the polar vortex. The strength is slowly subsiding but not at a noticeable level yet.

[NorthernRab]

Dundee isn't northern Scotland though. Even if you include Aberdeen and Dundee, the population of the cities mentioned is 400k. Stornaway only has 9k, and the other Scottish Islands aren't exactly heavily populated. It's not intended to be a dig at northern Scotland as I think it's beautiful, but the fact is that the areas forecast to be hit by blizzards are very sparsely populated compared to the rest of the UK (including southern Scotland).

1% of UK population = 620,000.

A'Ghaidhealtachd / Highland = 225,000

Na h-Eileanan Siar = 26,000

Moray= 87,000

Aberdeenshire = 245,000

Aberdeen City = 217,000

Shetland = 22,400

Orkney = 20,100

Perthshire = 147,000

Total (approx) = 950,000, not far from a million people. So in that respect you are very much incorrect.

[Osbourne One-Nil]

Ok!

[IDO]

1% of UK population = 620,000.

A'Ghaidhealtachd / Highland = 225,000

Na h-Eileanan Siar = 26,000

Moray= 87,000

Aberdeenshire = 245,000

Aberdeen City = 217,000

Shetland = 22,400

Orkney = 20,100

Perthshire = 147,000

Total (approx) = 950,000, not far from a million people. So in that respect you are very much incorrect.

Sorry on behalf of "Whitefox"; in fact 1.5% of UK pop. I am sure you know what he meant!

Edited January 2, 2012 by i'm dreaming of...

[Liam J]

I am viewing the Model Output Discussion Thread aren't I? :huh:

Edited January 2, 2012 by Liam J

[phil nw.]

OK,guys let`s leave the population of N.Scotland debate and get back to the Model Discussions--thankyou.

[Derp Patrol]

After a brief cooler day on Thursday, it really looks like a return of mild weather with high pressure to the south bringing in winds from the western quadrant. No chance of any 'big freeze' conditions for the foreseeable as it looks like our weather will be dominated from the west

Edited January 2, 2012 by phil n.warks.
Removed OT comments-we did ask

[Weathizard]

I'm a relative novice, so just wondering, why is the GFS control run so different to the op? Do they use different data?

[JP1972]

OK,guys let`s leave the population of N.Scotland debate and get back to the Model Discussions--thankyou.

Well come on, where is the Population of Northern Scotland thread?

I did enjoy the maths lesson though, very informative!!

Looking at the models and post from S Murr et al it would appear patience is very much key at present.

[weathe20]

It's a pity that you can't see signs of a change, Shed. I would have thought that with your experience you too could be picking out the clues that are being demonstrated hemispherically and in the ensembles.

Getting back to Steve Murrs point on a suspected pattern change, it was never going to be a quick one. Sadly, without a dramatic SSW the troposphere has been drip fed slow stratospheric mean wind changes and will continue to be so for the foreseeable future. It is akin to sitting in a bath with a leaking plug - the water is slowly going down but it is not noticeable at first. Then all of a sudden one realises that they are sitting in far less bath water than previous. The same is occurring with the polar vortex. The strength is slowly subsiding but not at a noticeable level yet.

Sheadhead would not except the NAO and AO and heading neutral or negative at the moment, so clearly hes not picking up on the 'signs' of a pattern change.

Edited January 2, 2012 by weathe20

[Harsh Climate]

Sheadhead would except the NAO and AO and heading neutral or negative at the moment, so clearly hes not picking up on the 'signs' of a pattern change.

Yes AO and NAO looking better by the day

We need them both below -2.

[Glacier Point]

Big, big spike in tendency of relative angular momentum showing up...

http://www.esrl.noaa...d.sig.90day.gif

and there's a big + Asian Mountain Torque in there which will: extend the Asian Jet into the Pacific setting up the conditions for the Aleutian ridge; and, bring about further wave breaking into the polar stratosphere for the next 10-15 days. It was a similar spike in angular momentum which preceded our cold outbreaks of the last two winters.

The ensemble means have, if anything, begun to lock onto a negative Arctic Oscillation with the 'switch over' centred around 11th January. GEFS control going through the floor. Most of the +ve anomalies centred on the Pacific and Siberian sectors.

http://policlimate.c...scillation.html

Long range tools indicate temperatures for our neck of the woods trending average or slightly below given night time frosts although there is something of a change in the pace of change during mid month as the possible double whammy of tropospheric changes and stratospheric warming (this one a plausible major mid winter warming) coincide around this time.

Northerly attacks along a trough dropping into Europe look the most likely pattern from mid month, potentially going more unsettled as the trough expands into the Atlantic - cold zonality anyone, followed by a genuine cold source Scandinavian ridge ?

Edited January 2, 2012 by Glacier Point

[weathe20]

and there's a big + Asian Mountain Torque in there which will: extend the Asian Jet into the Pacific setting up the conditions for the Aleutian ridge; and, bring about further wave breaking into the polar stratosphere for the next 10-15 days. It was a similar spike in angular momentum which preceded our cold outbreaks of the last two winters.

Think that in bold could get coldies excited. Can this mean synoptics simular to the last two winters?

[lorenzo]

GEFS control going through the floor. Most of the +ve anomalies centred on the Pacific and Siberian sectors.

http://policlimate.c...scillation.html

Long range tools indicate temperatures for our neck of the woods trending average or slightly below given night time frosts although there is something of a change in the pace of change during mid month as the possible double whammy of tropospheric changes and stratospheric warming (this one a plausible major mid winter warming) coincide around this time.

Northerly attacks along a trough dropping into Europe look the most likely pattern from mid month, potentially going more unsettled as the trough expands into the Atlantic - cold zonality anyone, followed by a genuine cold source Scandinavian ridge ?

Encouraging update GP, you did write something has got to give and the GLAAM figures delivered. Do you think this could be a winter of a double SSW? What are the key evolutions to look for for the development of the Scandi ridge?

[SMU]

better amplifiaction of the jet at 108 on the 12z

http://176.31.229.228/modeles/gfs/run/gfsnh-5-108.png?12

S

Edited January 2, 2012 by Steve Murr

[Frosty.]

The Atlantic 'train' seems to remain quite intense to me and that HP to our south is still playing at the party pooper.

There are stronger hints from the models that high pressure influence is slowly going to grow during the next two or three weeks, mainly for the south on and off initially and then more widely across the uk by the last week of jan with increasing amounts of frost and some fog but northern britain looks like being the last to see the change and will probably continue with the mixture of mild and cold zonal for the next few weeks at least with only shortlived ridges bringing any respite for the north although we can't discount something more dramatic occuring in the meantime, I noted that BFTP posted this morning that we will probably need to look northeast for the first proper cold spell instead of northwest, I agree that polar maritime incursions are never going to deliver the type of deep cold that most of us are looking for.

[cooling climate]

The UKMO is having none of what the GFS is showing in

the t120 time frame hence why no one has commented

on it I suppose.

[Frosty.]

The UKMO is having none of what the GFS is showing in the t120 time frame hence why no one has commented on it I suppose.

Can you please expand on that CC as I can't upload the charts in question, just taking a wild guess though, does that mean the ukmo is remaining mild zonal at T+120?

And what a brilliant update from GP, for all those who have been cheesed off by the models in recent weeks, that update should bring genuine hopes for the 2nd half of jan onwards, Northerly attacks sounds very good to me.

Edited January 2, 2012 by Frosty039

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

The control goes of the scale as GP mentions above, as well as one other member.

The mean a lot lower than the 18z from Jan 1st

[Cecil Hogmanay Melchett]

GFS and UKMO both continue the zonal theme this evening.

I really hope themodels start to pick up on these positive signals soon!!

[Tim Bland]

I see Gfs Op is back to its mild outlier routine again, I thought it had got over that!

[chionomaniac]

Here is another one to add to the list. I decided to look at the Copenhagen GFS 12Z ensembles.

[Cecil Hogmanay Melchett]

Here is another one to add to the list. I decided to look at the Copenhagen GFS 12Z ensembles.

something wrong with that grid C there is no way the copenhagen 850hpa mean temp is -1 or -2 in mid Jan!!!

Edited January 2, 2012 by happy days

[Paul]

something wrong with that grid C there is no way the copenhagen 850hpa mean temp is -1 or -2 in mid Jan!!!

Nothing wrong with the grid: