Model output discussion - 7th January onwards

[LRD]

16 minutes ago, Sweatyman said:

a weird hole in the midlands hmm

To be fair there are plenty of weird holes in the Midlands 

Increasing likelihood of colder weather for the last 10 days of January. According to some longer range models, an even more robust cold pattern could take hold next month

Edited January 10, 2019 by LRD

[WhiteFox]

8 minutes ago, Catacol said:

for a little bit we can afford to put the teleconnective charts away and forget macroscale pattern drivers, and instead enjoy a bit of fax chart scrutiny, weather radar updates and even some lamp post action. Lovely.

Indeed. I don't comment much on the model thread, preferring instead to absorb information and garner knowledge from those who have spent a lot of time studying drivers, but I correspond regularly by email with some fellow cold seekers and I'd pretty much said exactly the same thing. 

Given the ensembles and the signals given from longer range models (and ignoring the noise of individual operational runs) I'm almost as confident of a cold spell occurring from around 21st Jan this year as I was looking through the musings leading up to the cold last year. 

I think it's not a case of "if", but "when" and "how".

[Derecho]

19 minutes ago, Northumberland snowman said:

Very impressive they are. 

 

Look at the scatter though, many runs alternate between average and cold as a result of a cold zonal pattern. It isn't the persistent snowy cold that most are craving. There would be snow in the NW for many but this would quickly be washed away by rain... rinse and repeat whilst Northern blocking struggles to build.

The 06z parallel however shows the way once more.

[stodge]

Afternoon all

Again, I'm a little underwhelmed by the output but a couple of points of note across the models today.

First, our old friend the Canadian PV lobe - this may surprise some people but if you want prolonged cold you don't want it to disappear. Losing the PV completely sounds like Nirvana and of course a 1070MB Greenland HP is infinitely better than sub-990 MB heights but the problem becomes one of longevity. All too often the negative NAO becomes west-based as the HP ridges SW into Canada - that's what did for the December 2010 cold spell and indeed the rapid movement of the HP from Scandinavia to Canada in March 2018 set up a west-based negative NAO which again did for the initial cold spell.

Ideally, we need to see the PV displaced slightly to the west (allowing Scandinavian HP formation) or further to the west over Canada (supporting Greenland HP formation and with WAA continuing up the Davis Strait to maintain).

There are signs of the Canadian PV lobe displacing slightly SW and allowing height rises over Scandinavia (supported by the strat charts as Feb1991 mentions above). This is encouraging as the stagnant cold pool forming over Scandinavia will encourage heights to develop.

Second, timing. We've had a vortex displacement followed by a split. The standard displacement response, as we are seeing, is to re-enforce the Canadian lobe so we get a fired up Atlantic as cold air is displaced south. I'd hoped we would be seeing clear signs of amplification by the 22nd or 23rd of the month but we are still struggling to get clarity with the GFS output. and we are tantalisingly just beyond the edge of ECM and GEM output. It looks like an increasingly cold and unsettled outlook as the airflow shifts gradually from west to north. The question then becomes whether we can catch enough of a break to allow either a mid-Atlantic ridge or (and this now seems the form horse) heights to develop over Scandinavia in conjunction with lower heights over the Med.  

[Frosty.]

The GEFS 6z screams wintry potential in the mid and especially the longer term with a growing chance of snow..and not just in the north and on hills..overall, I think there is a strengthening signal for an exciting period of wintry weather which is not far away..I can't wait!!

[winterof79]

19 minutes ago, Quicksilver1989 said:

Look at the scatter though, many runs alternate between average and cold as a result of a cold zonal pattern. It isn't the persistent snowy cold that most are craving. There would be snow in the NW for many but this would quickly be washed away by rain... rinse and repeat whilst Northern blocking struggles to build.

The 06z parallel however shows the way once more.

I would say that most don't alternate near average as the mean remains firmly below average and it's trending lower as time moves on

Edited January 10, 2019 by winterof79

[Fozfoster]

52 minutes ago, Sweatyman said:

a weird hole in the midlands hmm

Yeah over my house............:(

[coldwinter]

New JMA weeklies seem to go the way GP was alluding to earlier, notice how solid that Euro trough is also

 

 

[SMU]

We need to get rid of the GFS.

Its entertainment factor is of course what it says 'entertaining' but it offers little real value.

5 pages on from this morning & pretty much ( with a few exceptions ) all thoughts / forecasts & rationale based on the GFS 06z suite.

Jeez talk about build your house on a plate of Jelly....

[Eskimo]

5 minutes ago, Steve Murr said:

We need to get rid of the GFS.

Its entertainment factor is of course what it says 'entertaining' but it offers little real value.

5 pages on from this morning & pretty much ( with a few exceptions ) all thoughts / forecasts & rationale based on the GFS 06z suite.

Jeez talk about build your house on a plate of Jelly....

People are free to discuss whatever model they want to discuss, that's why it's called the model discussion. Out of all the 'big' models, only the GFS has updated since 09:30 so there's going to be a lean towards GFS discussion. 

Edited January 10, 2019 by PerfectStorm

[Ali1977]

11 minutes ago, Steve Murr said:

We need to get rid of the GFS.

Its entertainment factor is of course what it says 'entertaining' but it offers little real value.

5 pages on from this morning & pretty much ( with a few exceptions ) all thoughts / forecasts & rationale based on the GFS 06z suite.

Jeez talk about build your house on a plate of Jelly....

I don’t know either way how it’ll pan out , what if the GFS has this nailed? Will your thoughts change on it? Personally I’m looking fwd to the UKMO, mainly as it looked like bringing the cold in earlier than the others - not sure it will be correct though. If it is then hats off to it.

Edited January 10, 2019 by Ali1977

[feb1991blizzard]

8 minutes ago, Steve Murr said:

We need to get rid of the GFS.

Its entertainment factor is of course what it says 'entertaining' but it offers little real value.

5 pages on from this morning & pretty much ( with a few exceptions ) all thoughts / forecasts & rationale based on the GFS 06z suite.

Jeez talk about build your house on a plate of Jelly....

Only if the replacement is definitely better.

[Bristawl Si]

59 minutes ago, Quicksilver1989 said:

Look at the scatter though, many runs alternate between average and cold as a result of a cold zonal pattern. It isn't the persistent snowy cold that most are craving. There would be snow in the NW for many but this would quickly be washed away by rain... rinse and repeat whilst Northern blocking struggles to build.

The 06z parallel however shows the way once more.

Your post also sums up Meto latest musings for end Jan and into early Feb (my interpretation at least).

[East801]

Looking at the wintry scenes across Europe it’s really frustrating that we remain on the outer limits of this cold and snowy weather which has engulfed much of mainland Europe.

The picture postcard scenes across Austria, Turkey and Germany really are quite something, feet of snow.

Here’s hoping our time is coming...we all deserve it after such a patient first half of winter.

Let’s hope the 12z can guide us closer ....

 

A

[Paul]

42 minutes ago, Steve Murr said:

We need to get rid of the GFS.

Its entertainment factor is of course what it says 'entertaining' but it offers little real value.

5 pages on from this morning & pretty much ( with a few exceptions ) all thoughts / forecasts & rationale based on the GFS 06z suite.

Jeez talk about build your house on a plate of Jelly....

And yet, 10 days ago, this ECM chart was being 'boomed' left right and centre, with the GFS apparently playing catchup / incorrect for whatever reason at that point too. 

The GFS at that time was way closer to where we've ended up though..

I'm not saying that because of this the ECM is rubbish and the GFS great, and the model scores certainly don't have the GFS beating the ECM or Meto right now, but just ignoring a major model which albeit behind isn't stupidly behind, is as worthless an exercise as taking any run from any model as gospel. 

Edited January 10, 2019 by Paul

[Selliso]

1 minute ago, East801 said:

Looking at the wintry scenes across Europe it’s really frustrating that we remain on the outer limits of this cold and snowy weather which has engulfed much of mainland Europe.

The picture postcard scenes across Austria, Turkey and Germany really are quite something, feet of snow.

Here’s hoping our time is coming...we all deserve it after such a patient first half of winter.

Let’s hope the 12z can guide us closer ....

 

A

Yes... although there is a reality from this kind of "stau-effect" feature in Austria.

The town I lived in several years ago has been almost inaccessible for a nearly a week, with the area declared a disaster zone.

9 feet of snow is putting structures under considerable stress, and they are enduring the highest possible avalanche warning level. Hopefully the army will be able to reach the valley with support flights tomorrow as the weather clears - then another round of heavy snow over the weekend.

I really do want the cold and snow as much as anyone else here, but I wouldn't call the current situation in parts of Austria a "picture postcard."

 

[karlos1983]

That's a T2 of -13C (at least) member on the ENS! Mean doesn't get above 5c from the 19th. Another fantastic set. The 4 members that can be assessed as mild, probably skew that mean of around 3C towards the end! Doesn't matter how you cut that, it's a very cold run . 

Edited January 10, 2019 by karlos1983

[Ali1977]

2 minutes ago, karlos1983 said:

That's a T2 of -13C (at least) member on the ENS! Mean doesn't get above 5c from the 19th. Another fantastic set.

Great set for London, a fair few warm stragglers will be dragging that mean up towards 1c too I imagine. The last few GFS have been pretty meh the last few runs for the medium term, we could do with an upgrade in those in line with the ECM maybe.

[Big Dave]

14 minutes ago, karlos1983 said:

That's a T2 of -13C (at least) member on the ENS! Mean doesn't get above 5c from the 19th. Another fantastic set. The 4 members that can be assessed as mild, probably skew that mean of around 3C towards the end! Doesn't matter how you cut that, it's a very cold run . 

Aren't there at least 2 or 3 members on the colder side that drag the mean down as well?   Meaning that the mean is the mean if you get my meaning. 

[Ali1977]

2 minutes ago, Big Dave said:

Aren't there at least 2 or 3 members on the colder side that drag the mean down as well?   Meaning that the mean is the mean if you get my meaning. 

We don’t worry about those !!!!!

What I mean is there are a fair warm members out on their own a bit, where there are no real out and out cold members. I take your point though.

[Sperrin]

3 minutes ago, Big Dave said:

Aren't there at least 2 or 3 members on the colder side that drag the mean down as well?   Meaning that the mean is the mean if you get my meaning. 

Better clustering in the colder runs and the outliers are definitely the milder runs. Perhaps the median would give a better indication when this is the case?

[karlos1983]

11 minutes ago, Big Dave said:

Aren't there at least 2 or 3 members on the colder side that drag the mean down as well?   Meaning that the mean is the mean if you get my meaning. 

good point! guess my cold Bias got in the way there lol - still cold though 

That said, it is only 1 member that goes off on one in terms of cold, although in some style... I'd like to see the synoptic version of that member 

Edited January 10, 2019 by karlos1983

[Geordiesnow]

26 minutes ago, Paul said:

And yet, 10 days ago, this ECM chart was being 'boomed' left right and centre, with the GFS apparently playing catchup / incorrect for whatever reason at that point too. 

The GFS at that time was way closer to where we've ended up though..

I'm not saying that because of this the ECM is rubbish and the GFS great, and the model scores certainly don't have the GFS beating the ECM or Meto right now, but just ignoring a major model which albeit behind isn't stupidly behind, is as worthless an exercise as taking any run from any model as gospel. 

Yep the ECM amplified charts in the day 9 to 10 range are just as predictable as the GFS long range charts really and as with any long range output it really should be taken with a whole lot of skeptism regardless what it shows.

In the more short to medium term, just how much half hearted amplification will we see in the Atlantic will depend how much polar air does come down from the North. Certainly no big freeze on the way but chillier and brighter conditons will be most welcome

 

[Big Dave]

25 minutes ago, karlos1983 said:

good point! guess my cold Bias got in the way there lol - still cold though 

To be fair, I only happened to notice as I was trying to keep my own cold bias in check! 

[BLAST FROM THE PAST]

4 hours ago, Ed Stone said:

What calamity, disaster and grief: everything's still pointing toward a colder pattern setting-in around or just after Jan 20th. What doom-and-gloom...Ignore the ongoing SSW and other teleconnections, and watch the seagulls instead...?

Warm sector being squeezed out like an unwanted spot ready to pop. That would have no warm up of consequence 

 

BFTP