Model Output Discussion 17th Dec.2013-12z onwards.

[shedhead]

I disagree. The pattern is looking to change in FI. To what, it's not sure, how, it's not sure but higher pressures to the north and lower to the south seem to be the key movement. The "form horse" is definitely not continuing vigorous Atlantic. 

If you disagree, can you please post charts to support your view, because whats below suggests weather eater is spot on with his contention.

 

No 'major changes' in the FI period you allued too either from what I can see.  'Tentative' signs of something 'potentially' colder and 'perhaps' more wintry towards mid month

covers things more than adaquately for now imo.

 

Edited December 27, 2013 by shedhead

[UV-RAY]

by the time it gets here, winter will be over...

 

Im clearly living on a different planet, but I am not seeing reasons for optimism (if its deep cold you're after).. I think It may be in the definition of cold. Cold to me, means minus values during day time. I don't see those kind of values in any recent output. The updated ec32, does not build heights over Scandi anywhere near the degree of the 12z op of earlier. While maintaining lower heights over us, to our NW, and for a while into Europe - before the signal recedes somewhat. We are left with a pretty unsettled picture throughout January, with at best below average values - but deep cold? Cant see it.

A cold spell isn't defined by the number of days with temps below zero. I'm beginning to think that some members definition of a cold spell have been distorted since December 2010.

 

Back to the models and in the reliable timeframe as one or two others have already said it's more of the same really, with wind speeds decreasing overtime. FI does look more promising for a pattern change but until we get to +144 it remains a distant dream but one which could deliver a potent beast from the east from mid month onwards perhaps. 

[TEITS]

Some interesting posts.

 

A pattern change is going to occur over the next 10 days but how will this impact us here in the UK is the big question for me. If we look at the link below you will see all of Europe is mild.

 

http://www.wetterzentrale.de/pics/Rtavn062.png

 

What is likely to happen is a very cold surge is likely to spread S into Russia and E Europe during the first week of Jan. However as per usual will this advect W and reach the rest of Europe including the UK is always uncertain especially at this range. Our chance of a cold spell is most likely to come from the E as opposed to a N,ly, however it could begin by a brief NW/N,ly if LP systems start tracking on a SE,ly trajectory.

 

At this stage I feel its foolish to assume our mild, stormy weather is going to continue into Jan. Im expecting the model output between +192 to +240 to swing wildly over the next few days which is why nobody can be confident of the outlook yet. The only confidence I have is a pattern change is going to occur but will it impact the UK??

[Downpour]

@Shed

So no signs or tentative signs? Which is it? To be clear, what do you expect the weather to be doing on Jan 10? From your posts today you have positioned yourself so you cannot be wrong. Cards on the table time.

[fergieweather]

(NB UKMO assessment of 00z suites awaited later this morning) With the upper pattern ever-amplifying it's unsurprising to see varied synoptic types appearing further ahead, but the key point of interest is a continued predominance of a decidedly unsettled story with some very deep lows littering MOGREPS-15 towards far reaches of recent output. A fair number of the members offer E'rly component with low to Biscay (ditto EC yesterday), but worth adding there's scant hint of anything profoundly blocked or deeply cold in EC32 right through to late Jan (consistent output re this for many runs now). Nonetheless, the MR trend period is a conondrum with a raft of possible outcomes for UK, albeit the cyclonic unsettled pattern, in one shape or another, looks very dominant.

Edited December 27, 2013 by fergieweather

[Captain Shortwave]

A couple things are worth noting from the output this morning.

1) Increasing confidence in heights remaining low over Greenland.

2) ECM ens show a clear split into 2??? solutions as we enter week 2, shown by the spread

Two solutions being either a continuation of the westerly pattern with temperatures around average, or the jet aligning NW/SE and developing low pressure close to Iberia/Biscay with a cooler easterly flow (I stress cooler as we would still have to wait a while to pull some Arctic air around any heights to the north).

If we are going to get cold, the form horse placement of any heights will be to the north east of the UK, hence the cold solutions being an easterly.

Edited December 27, 2013 by Captain shortwave

[bluearmy]

That ties in with the ECM mean at T240: EDH1-240 (1).gif

 

The s.Euro upper trough remains consistent. The surface pattern still has the flow from the west riding over the trough (hence signs of the AH ridging in), with a cut off mean low in s.Euro. We need a trigger to divert the surface flow SE and that I presume will draw in the colder uppers and then reinforce the mean upper Scandi ridge. The pieces are seemingly in place for a cold spell and with the upstream amplification forecast for the US, this could trigger the Canadian vortex energy SE and get things moving.

 

Second-Third week January potential maybe.

 

the ecm 00z extended are still in the same area - the azores ridge retrogresses to mid atlantic/se of newfoundland, the blocking centred nw siberia/ne scandi and the troughing from eastern canada following the jet across the atlantic through iceland and then dropping into europe in our area (as it cannot go ne). difference today is the azores ridge in the T168/T192 timescale is more evident and this prevents heights dropping convincingly in europe until the ridge around day 9 off the eastern seaboard draws it nw.   ian's tweet really not a surprise, given runs from the past week. i am a bit surprised to see so many comments re no sign of cold within ten days. that takes us to the sixth and the sixth was about the time when any cold would begin to show its hand, according to the ecm extended. 

[kev238]

This winter does feel very different to winters over the past few years; a roaring key and vigorous lows zooming by.

It appears that a major atmospheric change is needed to bring about a major change ; unsettled mild and wet, or unsettled average and wet must be considered the most likely options. Picking out random ensemble members and trying to present them as evidence of change is misleading .

[shedhead]

Some interesting posts.

 

A pattern change is going to occur over the next 10 days but how will this impact us here in the UK is the big question for me. If we look at the link below you will see all of Europe is mild.

 

http://www.wetterzentrale.de/pics/Rtavn062.png

 

What is likely to happen is a very cold surge is likely to spread S into Russia and E Europe during the first week of Jan. However as per usual will this advect W and reach the rest of Europe including the UK is always uncertain especially at this range. Our chance of a cold spell is most likely to come from the E as opposed to a N,ly, however it could begin by a brief NW/N,ly if LP systems start tracking on a SE,ly trajectory.

 

At this stage I feel its foolish to assume our mild, stormy weather is going to continue into Jan. Im expecting the model output between +192 to +240 to swing wildly over the next few days which is why nobody can be confident of the outlook yet. The only confidence I have is a pattern change is going to occur but will it impact the UK??

Given the current charts TEITS and in view of the fact Jan starts on Weds, it seems far more foolish to me to suggest the unsettled pattern is not going to continue into next month. (as for the mild and stormy bit, you added those words to describe the pattern going forward, I've not seen them used)

Edited December 27, 2013 by shedhead

[Weather-history]

I don't subscribe to "once zonality starts that's it for a long time". Zonality will last as long as it lasts depending on the state of the atmosphere and the variables at the time. It may take seismic shift to break out of the pattern, it may only take a small tweek. It may last for two months, it may last only two weeks. It depends on those variables for me.

[Summer Sun]

Looking at the models we have another windy spell to come on Wednesday

 

 

GEM on its on with a 1050mb Greenland high

Edited December 27, 2013 by Summer Sun

[legritter]

Morning all posters ,still a very disturbed Atlantic looking at todays Models .Yes we have signs of possibly something taking place in the further outlook which could benefit us coldies but  yet again its at the longer range .it could be a block setting up over n/west Russia or equally i feel a high pressure cell setting up further west ,or a continuation of the present Zonal train ,its just that at the 10 day range ifeel is always an eternity in meteorological ,Just going back 3 weeks in time and no sign realy of our current severe weather ,so what hope is there of getting MID January nailed from this distance ,plenty of time left so its a case i think of being patient ,And Crack open some STellas ready for this evenings runs ,CHEERS GANG 

[bluearmy]

This winter does feel very different to winters over the past few years; a roaring key and vigorous lows zooming by.It appears that a major atmospheric change is needed to bring about a major change ; unsettled mild and wet, or unsettled average and wet must be considered the most likely options. Picking out random ensemble members and trying to present them as evidence of change is misleading .

Where have random ens members been picked out as evidence kev? That normally happens when there is nothing in the ops or anomolys. We are a long way from there now. Plenty of ens means/anomolys pointing to cold into the second week jan. where will our little island sit in the pattern??

[draztik]

A cold spell isn't defined by the number of days with temps below zero. I'm beginning to think that some members definition of a cold spell have been distorted since December 2010.

Back to the models and in the reliable timeframe as one or two others have already said it's more of the same really, with wind speeds decreasing overtime. FI does look more promising for a pattern change but until we get to +144 it remains a distant dream but one which could deliver a potent beast from the east from mid month onwards perhaps.

you're focusing on the wrong section of my post. We could argue over a definition till we are blue in the face... The main point stands, I cant see cold conditions taking hold of our weather. And nothing I've seen this morning changes that.

the Canadian ens, keeps the unsettled outlook motoring along by 8 Jan, with near normal temperature conditions.

Edited December 27, 2013 by draztik

[UV-RAY]

you're focusing on the wrong section of my post. We could argue over a definition till we are blue in the face... The main point stands, I cant see cold conditions taking hold of our weather. And nothing I've seen this morning changes that.

the Canadian ens, keeps the unsettled outlook motoring along by 8 Jan, with near normal temperature conditions.

But any potential pattern change looks to be from the 10th onwards, the operative word being potential though. Edited December 27, 2013 by Sceptical Inquirer

[cooling climate]

GFS 06z out to t216 very consistent with the 0z output.

[Captain Shortwave]

Weak Greenland ridge again from the GFS. Though confidence I still feel is very low here. This isn't a definitive zonal pattern or blocking pattern. We are probably in reality looking at weak heights across the pole which could ridge into any gap where the tropospheric vortex is not set up. In reality this gives us a reasonable chance as Greenland and Scandinavia (The north Pacific is the other location) look like they have a decent chance of one of these weak ridges setting up shop, for at least a little while.

Question we have to sort before even contemplating colder weather is getting some reasonably consistency (cross model and run to run support) as well as seeing how much forcing on the jet these heights will have. Not enough forcing will result in the UK being very wet as opposed to cold with potential snowfall.

Edited December 27, 2013 by Captain shortwave

[shotski]

I am upbeat this morning after seeing the latest JMA medium range anomaly charts.

Mid Atlantic ridge seems to be where we could be heading in 10 days time or so and

also low heights into southern Europe and hints at some HLB anomalies to our north east.

[weather eater]

TEITIS is right there are some signs that temperatures look to drop over Europe which is good and he’s also right about the fact that for a sustained cold spell of the type we would all like to see we need an easterly set up. Yes I would agree that there is some movement in the pattern we have been experiencing, it does look like we are going to see changes to the PV and there are reasonable signs of heights over the pole, but unfortunately at the moment the impact on us looks relatively small. The upshot of the pattern change currently being modelled, is for a somewhat less vigorous Atlantic pattern with more of a polar maritime aspect at times, it will feel cooler and it will facilitate better chances of some winteriness over northern hills, really disappointing though it is say, the output is not pointing at much more than that and it is certainly not pointing at any kind of sustained cold spell, not a popular assessment I know and one I wish was otherwise

Edited December 27, 2013 by weather eater

[Jason M]

I'm always wary of GEFS Greenland highs as I feel GFS tends to over do them. There have been some decent FI charts over the last week but to me the clue is that few make it past the 10 day mark and that a been the case for the last week. Taken as a whole the output suggests to me that it's more of the same for the next few weeks.

Of course I could be wrong.

[Ali1977]

To me the charts have taken a step backwards this morning, no early to mid jan cold in the models

[cooling climate]

Very uninspiring run from the 06z GFS. In FI the 06z takes a differnt

course from the 0z run which can be expected but the consistency out

to t216 can not be ignored.

The Euro models still transfering Arctic heights into the northeast

although the ECM this morning is very poor as the heights sink away

southeast.

I still consider this to be the form horse and one to follow for cold

into the UK but given the consistency this morning by the GFS if this

does not change track in the next 24 hours then expect the Euro's to

revert to the GFS solution post t120.

[shedhead]

06 GFS continues to show a continution of the current pattern well into January, with a succession of LP's and their associated frontal troughs bowling in off the Atlantic at times. Temps look set to be near or a little above the seasonal average, with any wintryness being transient and largely confined to higher ground.

 

 

 

Even into FI it's hard to see a significant pattern change developing very quickly.

 

[TSNWK]

ECM 32 holding firm with the Westerly pattern right through to the end of January, to go along with the Susan Powell comments on boxing day that there are no signs of anything particularly cold for the next month. I also noticed that there were some eye candy ensemble members wheeled out last night, always a bad sign if its cold your looking for.

This mornings ECM is a horror show for cold and I thought that was what we were hoping the gfs would be trending too....

In a nutshell, you can have all the HLB you like, but until the Azores high moves away it ain't gonna do much good.

[shotski]

ECM 32 holding firm with the Westerly pattern right through to the end of January, to go along with the Susan Powell comments on boxing day that there are no signs of anything particularly cold for the next month. I also noticed that there were some eye candy ensemble members wheeled out last night, always a bad sign if its cold your looking for.This mornings ECM is a horror show for cold and I thought that was what we were hoping the gfs would be trending too....In a nutshell, you can have all the HLB you like, but until the Azores high moves away it ain't gonna do much good.

 

Sorry but where did you get the information about the ECM 32 , are you a subscriber ?

Edited December 27, 2013 by shotski