Winter Model Discussion - Cold Hunting -12Z 03/01/13

[IDO]

So at last the op and control trying to set a trend for cold. In reality little change from yesterday, in that no severe cold is showing on the 850s (excluding outlier control):

The op is an outlier late on as to 500mb patterns. However the GFS is clearly changing tact with strong support amongst the ensembles for ridging around the UK in around a weeks time: http://www.meteociel...&mode=6&ech=192

The GEFS mean highlights this:

In FI lots of outcomes, only 2/3 support the Op/control (heading for very cold, down on yesterday) with some poor ones and some cool and some coldish there as well. Early days yet but the spread highlights the uncertainty for the UK long term:

ECM is slower to the party:

By the end of the weekend we should know if this ridging near the UK is the next pattern (50;50 currently), and if it is, then many more ensemble members should start showing a colder FI. If the ridge fails to extend north then the outlook will not be so good in the medium term, with a zonal flow back.

Looking at the strat thread and nearly all positive news so we could see some very interesting charts develop shortly:

EC32: MattHugo81

Caution urged as it's a big change from last update, but latest EC32 shows a much colder outlook for 2nd half of January. Greenland block.

04/01/2013 07:08

Edited January 4, 2013 by i'm dreaming of...

[lorenzo]

The split is gaining strength on wave 2 and this was an encouraging height chart to see on the ECM Berlin site.

ECM definitely slower to join in with the GFS cold party.. Mr MJO perhaps responsible here.

GFS quick

UKMO getting quicker

ECM slower

With that particular phase displayed by the ECM, the analogs will be at odds with building heights to the North, however with the strat charts above it will change it's outlook over the next 48 hrs.

Either way it is a potential cold win, if ECM is correct and the MJO phases move at this pace, the ECM then coincides with the secondary response to the warming as Stewart mentioned, confident of the largest remnant vortex section over Scandi circa 26th Jan, combined this with ECM lag for a blocking pattern via MJO and a robust Greenland High is on the cards.

Main area of vorticity on the smaller and stronger post split vortex backing up and moving away from Greenland at 240 hrs.

Then, the crazy cold GFS , I know this is way in FI and also something of a cold outlier on the op towards end of FI, so just for fun minus 18 degree uppers exiting the Scandi continental shelf into an inbound pool of solid -16. Bonkers.

Edited January 4, 2013 by lorenzo

[Craigers]

LIke TETIS has been saying, the westward correction is still taking place in the GFS Charts. See the low pressure shifting South west slightly on the 00z chart compared to the 18z.

18z

00z

If we keep seeing this westward development then i will be getting very optimistic!

Edited January 4, 2013 by Craigers

[Frosty.]

Now that's more like it, and the gfs 00z shows a colder trend and more generally anticyclonic from the middle of next week onwards with frosts becoming more widespread and sharper, we could actually tap into the very cold air before the gfs shows it but it's a very promising run for coldies.

[snow drift]

1. Why are people guessing at the result of the SSW when no one knows the result for us?
   
2. Why do we need to be told that it won't be good for us, When no one Knows?
   
3. Why is the GFS wrong and ECM right, when no one knows?
   
4. To many people want to make a judgement in the hope that they can say told you so.
   
5. There is more chance of cold now than there has been due to various indicators, so lets see how it pans out. I think everyone knows we may miss out but.....
   
6. Lets see where we go from here and learn as we go.
   

[Polar Maritime]

1. Why are people guessing at the result of the SSW when no one knows the result for us?
   
2. Why do we need to be told that it won't be good for us, When no one Knows?
   
3. Why is the GFS wrong and ECM right, when no one knows?
   
4. To many people want to make a judgement in the hope that they can say told you so.
   
5. There is more chance of cold now than there has been due to various indicators, so lets see how it pans out. I think everyone knows we may miss out but.....
   
6. Lets see where we go from here and learn as we go.
   

It's called "Model Watching" and picking up on trends.

This morning there is a very strong trend for cold from mid month.

The SSW only helps matters.

[cold snap]

Newsflash from matt hugo on twitter

Ecm 32 dayer goes now for greenland block and colder 2nd half of Jan

[Polar Maritime]

Now that's more like it, and the gfs 00z shows a colder trend and more generally anticyclonic from the middle of next week onwards with frosts becoming more widespread and sharper, we could actually tap into the very cold air before the gfs shows it but it's a very promising run for coldies.

Yes Frosty, very promising from the GFS, we just need to ECM on board as Chio says prob playing catch up with MJO, model watching at it's best over the next few days

[mulzy]

Very mixed bag this morning, with prospects for cold in the 7-10 day period maybe receding a little. Significant differences at day 6 on the operationals - ECM being the most progressive, UKMO and GEM being in the "half-way house" camp while the GFS and NOGAPS showing some ridging north.

ECM

UKMO

GFS

GEM:

NOGAPS

Edited January 4, 2013 by mulzy

[Mark Parsons]

1. Why are people guessing at the result of the SSW when no one knows the result for us?
   
2. Why do we need to be told that it won't be good for us, When no one Knows?
   
3. Why is the GFS wrong and ECM right, when no one knows?
   
4. To many people want to make a judgement in the hope that they can say told you so.
   
5. There is more chance of cold now than there has been due to various indicators, so lets see how it pans out. I think everyone knows we may miss out but.....
   
6. Lets see where we go from here and learn as we go.
   

If we took on this philosophy then why would we have a forum!!! Chill out man!!

[johnholmes]

The 500mb ECMWF-GFS issue this morning still builds the ridge over/N/NNE of the UK. I am still not 100% convinced but remain at about 80% that a cold block type of set up is being put into place.

How all the links fit or not I will try and show during today with the Friday upper air update.

[Coast]

Now that's more like it, and the gfs 00z shows a colder trend and more generally anticyclonic from the middle of next week onwards with frosts becoming more widespread and sharper, we could actually tap into the very cold air before the gfs shows it but it's a very promising run for coldies.

Nicely highlighted by GFS Free Atmosphere Meteogram for London typically:

[Duane S.]

Doh! Just spent ages typing loads then loaded up a page on this tab and lost the lot.

Basics was.

No worries at all from me about the GEFS ens. They will never get 'progressively' colder, they are as prone to fluxuations as Operational. Yeah sort of defeats the object but there you go.

As I have been doing, here are two eye candy members for the 15th. Again, they are getting easier to find, the good ones look even better and the poor ones look less poor. Now that's a trend!

Control just because it's pretty insane and no.2 (although there are better) just because it's been keener than most about this cold spell in recent days!

What I really like is seeing models toy with EITHER a Greenland based high OR a Scandi based high.

Consistencies in the NH? Not much but again there is the interest in a strong North East Pacific ridge. ..

This will likely boost help polar heights and then later I can this ridging down over our side of the hemisphere coinciding with WAA surge of our own.

MJO could well be the icing on the cake though. At the moment looking very good with most forecasts showing it heading toward 6 then 7/8 at what would be just about perfect timing to reinforce northerly blocking. Like I've said before though 4/5 is a poorly forecast area so expect to see a few different ideas when it emerges from Asia, hopefully nicely amplified.

Happy days!

[snow drift]

If we took on this philosophy then why would we have a forum!!! Chill out man!!

The problem with the written word I guess. I am not suggeting people should not discuss the output but if you look back over the last few pages you will see that people are telling us that it will/won't be cold. The point was that we are not sure with much to be resolved. It is misleading to many when we are told that the we will miss out yet the back ground indicators suggest there is a strong possibility of cold reaching our shores.

Appologises to all who thought I was going off on one.

[Methuselah]

1. Why are people guessing at the result of the SSW when no one knows the result for us?
   
2. Why do we need to be told that it won't be good for us, When no one Knows?
   
3. Why is the GFS wrong and ECM right, when no one knows?
   
4. To many people want to make a judgement in the hope that they can say told you so.
   
5. There is more chance of cold now than there has been due to various indicators, so lets see how it pans out. I think everyone knows we may miss out but.....
   
6. Lets see where we go from here and learn as we go.
   

I'd have thought that the answers to those questions are pretty self-evident, SD: we don't know ergo we guess?

[Timmytour]

Whybother having discussions about upcoming football matches on TV and radio when no one knows what the results will be?????!!!!!

After "that ECM" it was like commenting on an expected outcome and then seeing QPR beat Chelsea.

Now we've moved on from assessing Reading's chances away to Man Utd. Looking at the models and wondering whether the cold is coming is now a bit like lloking at the tables, recent form and the availability of players and wondering whether Everton can beat Man City at home.

[I remember Atlantic 252]

Whybother having discussions about upcoming football matches on TV and radio when no one knows what the results will be?????!!!!!

After "that ECM" it was like commenting on an expected outcome and then seeing QPR beat Chelsea.

Now we've moved on from assessing Reading's chances away to Man Utd. Looking at the models and wondering whether the cold is coming is now a bit like lloking at the tables, recent form and the availability of players and wondering whether Everton can beat Man City at home.

At least for netweather 'That ECM' created a record user amount during 18Z on Wed 05 Dec, even though the beasterly was in FI

[Gibby]

Good morning. Here is the report of the 00z output from GFS, UKMO, GEM and ECM for today Friday January 4th 2013.

All models show a mild and moist westerly flow over the UK under the influence of a strong High to the South. Through the following few days changes to this overall pattern will be slow with just the mildest of the uppers leaking away somewhat with time. Secondly as we approach the new working week and probably most likely on Tuesday the High gives ground sufficiently to allow a weak front to cross over the UK with a band of rain though amounts in general will be small. By midweek the trough has passed and High pressure regains control close to the South, though in less mild air than recently.

GFS then shows High pressure ridging North through Britain to form a closed centre to the North of Scotland allowing a slack Easterly flow to develop over England and Wales with progressively colder conditions developing with frost and fog patches overnight though it would likely stay dry. In FI this morning the Jet Stream pulls South in the Atlantic and a very cold pool develops over Europe. The combination of the two engage late in the output to raise pressure to the North and Northwest pulling increasingly cold and eventually bitter air West from Europe over the UK as Low pressures are steered with the Jet flow well to the South. As shown this would make for a spell of sub zero temperatures day and night for many with frequent snow showers or longer spells of snow moving in from the East.

The GFS Ensembles show the operational only an outlier right at the end while the control run shows a major severe cold outbreak in its second half. There is still plenty of scatter between members in the second half of the run with plenty of mild options still shown but the trend towards colder scenarios developing over subsequent runs is increasing.

The Jet Stream shows a continuation of the current flow up and over the UK before the flow decomes disrupted and blocked in a week or so with a returning flow SW from Northern Europe hinted at late next weekend with a compensatory Northward drift high to the Arctic in the Eastern Atlantic.

UKMO for midnight on Thursday shows High pressure close to SE England with a ridge North over the East of the UK. A SW flow is blowing over the NW. A lot of dry weather is still shown over the UK at this stage with perhaps some rain and drizzle from weak troughs in the NW. It would be less mild than recently with perhaps some frost and patchy fog towards the South and East.

GEM shows a High pressure ridge over the UK at the same time pulling away slowly East over Europe in the following days leaving a slack South or SW flow over Britain with fairly benign if less mild conditions continuing.

ECM finally shows a trough crossing East next Thursday with some rain followed by more High pressure close to the South bringing a return to dry, less mild conditions with patchy frost and fog later. On Day 10 the Jet flow is shown to be more disrupted with cold air establishing over Europe. In the days that follow Day 10 the likelihood of colder weather for the UK looks like increasing as High pressure builds over Scandinavia and falls to the West.

In Summary there is still a lot of quiet, benign type weather to come over the next 7 days or so. Thereafter, there are signs of developments turning conditions rather colder and more interesting for those looking for cold as High pressure starts to build in more favourable locations. If the GFS Control run and to a lesser degree the operational run at the end would have us believe we will be well and truly in the freezer in two weeks time but support is still too sketchy to get too concerned at this range. Nervertheless, if its trends we are looking for at that range there is a definitive trend towards a more wintry look to things slowly taking shape, especially given the rumblings of the Professionals who are quite openly talking about the chances of a marked change towards late January on the media. It will be interesting to see how things develop on the models over the coming week or so as that time comes nearer.

[jessandjon]

Slowly but surely coming... (the cold that is )

Ha! Lol

[SMU]

Steve - remember your own words about what you call the F.F.S in FI !

I'm a little concerned that no other models are building pressure to the North in anywhere near the same way as the GFS control and OP, and I think some sort of flattening is likely, whether we will get another shot a bit later in the month we will have to see.

The GFS is the most extreme Northerly solution with the ridge, the ECM is the most flat- UKMO in the middle- but a big move from yesterday-

We need the most extreme solution to varify if we want that cold shot from the east- anything flatter & the train will be stopping in Europe..

S

[Snowman31]

shame the cfs can't be trusted. Lovely run though.

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=174&mode=0&carte=1&run=10

Edited January 4, 2013 by Snowman31

[The PIT]

Well until all the models jump on board I'll take it all with a pinch of salt. Normally where the ECM leads persistently the GFS and the rest eventually follow.

[TEITS]

The GFS this morning isn't far off what I referred to last night.

http://www.wetterzentrale.de/pics/Rtavn1441.png

Remember I said about the N,ly flow down the N Sea into Germany on the 18Z but if we look at the 0Z the N,ly flow is now reaching into Holland/Belgium. You may wonder why im fixated with these N,lys and the reason for this is because the further N & W the ridge of HP is the better because the N,ly flow will then veer NE then E. Basically the Siberian express will pass through the UK instead of coming to a halt further E.

The ECM at +144 is pretty rubbish compared to the GFS but the UKMO is an improvement and moving more towards the GFS. looking at the other models the ECM seems to be the outlier at the moment but unfortunately that doesn't make it wrong.

[Theresnoway]

The GFS this morning isn't far off what I referred to last night.

http://www.wetterzentrale.de/pics/Rtavn1441.png

Remember I said about the N,ly flow down the N Sea into Germany on the 18Z but if we look at the 0Z the N,ly flow is now reaching into Holland/Belgium. You may wonder why im fixated with these N,lys and the reason for this is because the further N & W the ridge of HP is the better because the N,ly flow will then veer NE then E. Basically the Siberian express will pass through the UK instead of coming to a halt further E.

The ECM at +144 is pretty rubbish compared to the GFS but the UKMO is an improvement and moving more towards the GFS. looking at the other models the ECM seems to be the outlier at the moment but unfortunately that doesn't make it wrong.

And worth remembering that the ECM is curently the best verifying at 6 days, according to the data I saw a couple of days ago. But that can change, especially as the forecasted synoptics are now very different.

Edited January 4, 2013 by Theresnoway

[Weather Boy]

Well until all the models jump on board I'll take it all with a pinch of salt. Normally where the ECM leads persistently the GFS and the rest eventually follow.

I'm struggling to see the basis for this statement, and enquire what evidence you have to back it up.

On the verification stats, as I understand it, the ECM is marginally ahead of the GFS (although it's complicated by the GFS having multiple daily runs) but the margins are so tiny, that one can't leap to the conclusion that the GFS is sure to follow the ECM.

Which model picked up that the progged easterly last month was going to fail? The GFS (18z) if I recall correctly, and then the ECM and eventually the UKMO fell into line.

That said, I am not saying that the GFS will win the day. I agree that it is a concern that the ECM is not on board (see Steve's post above) and until it jumps aboard, surely every sensible model watcher should say that predictions of real cold should be treated sceptically.

However, I don't see any basis for predicting the opposite. You could just as well say that the ECM will in time follow the GFS - such a statement needs evidence to back it up.