Winter Model Discussion - The Hunt For Cold -12z 14/12/12

[Jason T]

The West get another soaking, like they need it.

[snow1975]

Would this chart be cold zonal due to the PV so far south, akin to Jan 1993 or Jan 1984?

Edited December 14, 2012 by snow1975

[on the coast]

Few models that I don't think have been posted.

BOM

http://modeles.meteo...om-0-192.png?12

JMA

http://www.meteociel...92-21.GIF?14-12

No disrespect but after reading Fergie's post I really couldn't careless what the Met O are saying. The combination of all todays output and the disagreement shown means nobody has the foggiest how this will pan out.

Agree. Still have a hunch about a change around Christmas time though. Viewing next weeks models around Wed-Thur may well be interesting.

[If Wishes made Weather]

In this chart we have winds coming from North Africa, ill be sun batheing on Barry Island if that comes off! http://cdn.nwstatic....192/h500slp.png

It is pretty hard seeing charts showing that northern Florida will be similar, if not colder than parts of the UK (T186 circa)

[nick sussex]

In a true sense of bitter irony the upstream amplification we've hoped for arrives at completely the wrong moment.

You want this to happen with troughing to the west of the UK, once the trough gets too far east you end up with an Aussie barbecue for Xmas in the current set up.

The good thing about the GFS at the moment is that its probably wrong, overall apart from the GFS attempts to have everyone reaching for the prozac, the outlook remains rather average with a chance of some colder conditions especially for more northern and ne areas.

Much depends on whether we see any further northwards trend in the jet across the less hysterical models, if it goes north its milder, south colder.

Edited December 14, 2012 by nick sussex

[Panayiotis]

Who wants a bit of zonal weather then? Has the GFS picked up on something, moving the PV around the Greenland area? (I hope not!)

[Paul T]

Whoo..... I so WISH I could show you the full, amazingly 'micro-variation' replete suite of EC products!!! You'd retract that view instantly!!! :-)

My inital response got deleted by mods, so i shall try again.

I think you will appreciate that my response was in the context of what is available to mere mortals, and yes, i do wish that you could show me all of the EC products! lol

[Weathizard]

Jesus christ the size of that Vortex to our north? Doesn't make sense given warmings and ect going on, surely the GFS defaulting and ramping it up as usual? Hope the 'trend' is stopped and soon, Azores high/Bartlett/Zonal train coming if this run is correct (which itsprobably not)

Let's hope the EnS offer some hope.

[Glacier Point]

Hi GP, when do you think we will start seeing a pattern change, hopefully for colder conditions? early jan? mid jan?

Period between Christmas and New Year holds a modest level of interest, around 10th Jan I think things begin to get interesting.

[Panayiotis]

Another grim GFS run for us coldies, I just hope its wrong and we get another cold shot before the New year.

[Liam J]

I did mention the 90's on the last page - charts like these remind of the 97/98 Xmas periods, another Boxing Day storm anyone.....

[LomondSnowstorm]

Would this chart be cold zonal due to the PV so far south, akin to Jan 1993 or Jan 1984?

Yep, this is the second GFS run to do this in FI, which for the moment means relatively little but that is the one rather fun (and unexpected) aspect of über zonality with total control from the PV.

[Paul T]

No disrespect but after reading Fergie's post I really couldn't careless what the Met O are saying. The combination of all todays output and the disagreement shown means nobody has the foggiest how this will pan out.

'pan out' being how long?

[OldMetMan]

In a true sense of bitter irony the upstream amplification we've hoped for arrives at completely the wrong moment.

You want this to happen with troughing to the west of the UK, once the trough gets too far east you end up with an Aussie barbecue for Xmas.

The good thing about the GFS at the moment is that its probably wrong, overall apart from the GFS attempts to have everyone reaching for the prozac, the outlook remains rather average with a chance of some colder conditions especially for more northern and ne areas.

Much depends on whether we see any further northwards trend in the jet across the less hysterical models, if it goes north its milder, south colder.

Yes, I agree about the GFS. What I find so odd about its continuity and logic is how it goes off at a tangent for no obvious reason. It's showing an entirely reasonable development up until around T180 - amplifying upper trough to the W, a slower moving LP drifting N over Canada and then suddenly whoosh, it destroys all the meridionality is about 48 hours!

Assuming it is getting nearer the mark up until T180, that's a very familiar scenario - IF the amplified flow persists - for a HP build from the E or NE as the upper ridge builds NE. It's a big IF though but encouraging nevertheless.

[If Wishes made Weather]

The very last slide shows the jet on the Pacific side going way down in the Pacific in Mexico, generally it seems to loose some power over the Atlantic, and the 10hPa warming shows it to be in the +4 area over the gulags. This warming seems to turn up very rapidly over the stretch of just a couple of days. The vortex is broken in two with the larger part remaining over the Hudson - Greenland - and just to the north of the UK putting some cooler air into Scotland. Don't really see though how from this pattern, we get into winds from the northern or eastern quarters to pull much colder air over us.

[Backtrack]

Period between Christmas and New Year holds a modest level of interest, around 10th Jan I think things begin to get interesting.

Didn't you say January was likely to be the coldest period anyway, GP?

[Paul T]

Just to put the 18z in perspective, the wind direction is as follows:

1 day SW

2 day SW

3 day SW

4 day SW

5 day SW

6 day SW

7 day W

8 day SW

9 day SW

10 day NW

11 day SW

12 day W

13 day SW

14 day W

15 day SW

16 day SW

I was hoping for a XMAS miracle, but no.....

[John Badrick]

So here we are again.......when models showing freezing temps and snow for all we all get over excited and believe them as gospel. That didn't happen of course..Now models saying the complete opposite and we may have BBQ weather in January in a matter of days and we all get deprest.

After reading models during last two weeks We must, must NOT take them seriously after 5 days. People saying its going to be mild over Christmas because the model say so, or its not going to be cold until 2014, or we are going to have blizzard conditions in February are just stupid. Looking at he bigger picture is more important

[Panayiotis]

So here we are again.......when models showing freezing temps and snow for all we all get over excited and believe them as gospel. That didn't happen of course..Now models saying the complete opposite and we may have BBQ weather in January in a matter of days and we all get deprest.

After reading models during last two weeks We must, must NOT take them seriously after 5 days. People saying its going to be mild over Christmas because the model say so, or its not going to be cold until 2014, or we are going to have blizzard conditions in February are just stupid. Looking at he bigger picture is more important

The thing is though we did have freezing temperatures and the models were absolutely right about this, however its where the snow comes in that people think the models were wrong about. Its the people who went ramping about snow 1 week before the event who should be blamed for misleading other people, and as you know snow cant be accurately fore-casted from 48hrs away let alone 7 days. But so far the trend so far is showing no or little cold,in the next week. Edited December 14, 2012 by panayiotis

[Paul T]

So here we are again.......when models showing freezing temps and snow for all we all get over excited and believe them as gospel. That didn't happen of course..Now models saying the complete opposite and we may have BBQ weather in January in a matter of days and we all get deprest.

After reading models during last two weeks We must, must NOT take them seriously after 5 days. People saying its going to be mild over Christmas because the model say so, or its not going to be cold until 2014, or we are going to have blizzard conditions in February are just stupid. Looking at he bigger picture is more important

Trouble is John we do look at the bigger picture; the bigger picture is looking at ALL models, ALL ensembles and ALL available maps and graphs..... and at the moment they ALL look shocking!

[nick sussex]

Yes, I agree about the GFS. What I find so odd about its continuity and logic is how it goes off at a tangent for no obvious reason. It's showing an entirely reasonable development up until around T180 - amplifying upper trough to the W, a slower moving LP drifting N over Canada and then suddenly whoosh, it destroys all the meridionality is about 48 hours!

Assuming it is getting nearer the mark up until T180, that's a very familiar scenario - IF the amplified flow persists - for a HP build from the E or NE as the upper ridge builds NE. It's a big IF though but encouraging nevertheless.

The problem is that its earlier view regarding the shortwave which heads to Greenland does impact on the initial angle of the approaching low.

There was also talk upstream by NOAA of differences between the ECM and GFS at day 7 in relation to the handling of low pressure near Quebec so this will probably impact on events upstream.

The latest UKMO fax chart for 120hrs certainly looks to have a little potential, its a shame we couldn't have had a cleaner ejection of that shortwave into the continent , this would certainly have helped add a bit more negative tilt to the approaching low with more energy going se as we'd have seen more forcing with the ridge to the east backing further west.

http://www.meteociel...fax/fax120s.gif

The 120hrs sums up recent weeks, oh these shortwaves!

Edited December 14, 2012 by nick sussex

[Man With Beard]

Just to put the 18z in perspective, the wind direction is as follows:

1 day SW

2 day SW

3 day SW

4 day SW

5 day SW

6 day SW

7 day W

8 day SW

9 day SW

10 day NW

11 day SW

12 day W

13 day SW

14 day W

15 day SW

16 day SW

I was hoping for a XMAS miracle, but no.....

In terms of looking for cold, I see things a bit differently when there is a block to the east - I look for how close the east wind gets to Kent. Less than 500 miles out at T168 and I'm interested. Usually comes to nothing but sometimes moves in our favour (i think last Feb was a little like this, also Feb 2009?). On this basis, the current situation is still worth watching though not looking as promising as yesterday for sure.

[swfc]

Trouble is John we do look at the bigger picture; the bigger picture is looking at ALL models, ALL ensembles and ALL available maps and graphs..... and at the moment they ALL look shocking!

good post there.it does seem that a zonal spell of weather for some people is unacceptable even if its stairing them in the face.you can talk to you are blue in the face about trends and background signals but they have been tossed about for over a month and not really delivered. I myself am really disappointed with the current output but putting spin on it is not going to change the outcome however terrible it is from a cold fans perspective.

[fergieweather]

My inital response got deleted by mods, so i shall try again.

I think you will appreciate that my response was in the context of what is available to mere mortals, and yes, i do wish that you could show me all of the EC products! lol

Tell you what, here's a thought: I'll negotiate to get permission to show some recent post-hoc products on here if possible, such as the frontal position/shortwave spaghetti plots; MSLP dalmatian plots etc as it would seem a pertinent posting on this thread to help illustrate the sort of vast MRF suite available to folks at Exeter from EC when they prepare their analyses (of course they also regularly employ ARPEGE for these, too.... never seen it cited on this thread, strangely, but maybe it's not on public web access I guess?)

[TEITS]

Just to put the 18z in perspective, the wind direction is as follows:

1 day SW

2 day SW

3 day SW

4 day SW

5 day SW

6 day SW

7 day W

8 day SW

9 day SW

10 day NW

11 day SW

12 day W

13 day SW

14 day W

15 day SW

16 day SW

I was hoping for a XMAS miracle, but no.....

Indeed but the 0Z ECM had an E,ly at 240, So does the BOM, ECM 12Z SSW,ly, ECM 12Z control run is sub zero and to finally cap it off the ECM ensemble mean at +168 is nothing like the 18Z GFS.

Make a forecast out of that lot!!