Model output discussion - 5th December 2016 - Into Winter we go

[bluearmy]

3 minutes ago, blizzard81 said:

There is one possible explanation for this - both the EC and glosea seasonal models are wrong. Time will tell of course but quite telling that the EC 46 dayer has shifted away from the overwhelming northern blocking signal during the last 2 updates.

it has ?

[fergieweather]

1 minute ago, blizzard81 said:

There is one possible explanation for this - both the EC and glosea seasonal models are wrong. Time will tell of course but quite telling that the EC 46 dayer has shifted away from the overwhelming northern blocking signal during the last 2 updates.

Ermm... but that's the point. Has the blocking signal actually now delayed to manifest in Jan-Feb, rather than Dec?? EC Monthly only takes us to early Jan. Bear in mind the Mon update was starting to show strengthening +ve MSLP anomalies over Scandinavia tail-end Dec into first days Jan. So it may yet dovetail with EC Seasonal but we can't be sure if or at what lead time. But no model shows roaring zonality into those lead times: Glosea weakly favours something zonal early Jan, BUT that's set against a wide synoptic spread in it's members.

[No Balls Like Snow Balls]

11 minutes ago, karlos1983 said:

Hmm, although good news, I think I'll take that with a pinch of salt for the sake of my sanity.

 

 

 

Considering we are already 8 days into Dec, and the update is still highlighting a -NAO in erm...Dec Lol,  I think it needs a Mount Everest size pinch of salt. 

Edited December 8, 2016 by No Balls Like Snow Balls

[mountain shadow]

13 minutes ago, Summer Sun said:

 

If we're going to see a DISTINCT -NAO in December there will have to be a quick and remarkable change in the model output soon. The NAO as far as I can see is mainly neutral or slightly positive for the foreseeable, I certainly cannot see a distinct -NAO, and by distinct I would expect a figure of at least -2 or below on the scale.

[fergieweather]

1 minute ago, mountain shadow said:

If we're going to see a DISTINCT -NAO in December there will have to be a quick and remarkable change in the model output soon. The NAO as far as I can see is mainly neutral or slightly positive for the foreseeable, I certainly cannot see a distinct -NAO, and by distinct I would expect a figure of at least -2 or below on the scale.

I think Matt Hugo meant Jan-Feb. The model update today doesn't cover Dec.

[ArHu3]

 

I saw this tweet, I have no clue what the EPO is but looking at historic data it always seems to go way down about a week before a cold spell and predicted to go way down for the next 10 days or so

 

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/epo.png

Edited December 8, 2016 by ArHu3

[blizzard81]

13 minutes ago, fergieweather said:

Ermm... but that's the point. Has the blocking signal actually now delayed to manifest in Jan-Feb, rather than Dec?? EC Monthly only takes us to early Jan. Bear in mind the Mon update was starting to show strengthening +ve MSLP anomalies over Scandinavia tail-end Dec into first days Jan. So it may yet dovetail with EC Seasonal but we can't be sure if or at what lead time. But no model shows roaring zonality into those lead times: Glosea weakly favours something zonal early Jan, BUT that's set against a wide synoptic spread in it's members.

I remember a few winters ago (maybe 2012/13) the EC seasonal was signalling northern blocking and kept delaying it with every update. Very similar to this year.

[bluearmy]

6 minutes ago, ArHu3 said:

 

I saw this tweet, I have no clue what the EPO is but looking at historic data it always seems to go way down about a week before a cold spell and predicted to go way down for the next 10 days or so

 

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/epo.png

isn't he talking about the states though ??

[ArHu3]

Just now, bluearmy said:

isn't he talking about the states though ??

I guess but I looked at the raw data myself and noticed significant drops before known historic cold spells

 

ftp://ftp.cdc.noaa.gov/Public/gbates/teleconn/epo.reanalysis.t10trunc.1948-present.txt

[phil nw.]

A couple of posts have been removed that had only banter and no model related views.

Just a reminder please stay on topic in this thread and use the other threads where necessary.

Thanks.

[fergieweather]

Apols - Matt was indeed referring to Dec-Jan based on latest EC NAO plots. As you were...:-)

[blizzard81]

40 minutes ago, bluearmy said:

it has ?

Well, I can only go on reports I've read on this forum which indicated that northern blocking had been watered down for Dec on the last couple of updates.

[blizzard81]

1 minute ago, fergieweather said:

Apols - Matt was indeed referring to Dec-Jan based on latest EC NAO plots. As you were...:-)

Does this mean that Dec is not totally doomed to westerly mobility?

[phil nw.]

It's unusual to read how the 2 sets of ens outputs show somewhat different solutions going forward with the EPS less keen on amplifying the Atlantic pattern in week 2.

A look at the 06z gefs  for 17/12- the date i have been counting down from for a few days now- compared to ecm mean

                                                                      

granted there is a 6hr difference but we see how the majority of the gef stamps have the high further north with only around 4/20 showing a flatter pattern with a south westerly over the top.

A look at the London temp graph

underlines i think that we are more likely to get surface cooling with the current gfs solution with the high over us.That cold dip at day 10 from the ecm line seems to be because of the north westerly incursion from a transient Scandi.trough shown on the Op run.

I guess we are none the wiser where we go after the next 6/7 days.All i know from following the gefs to what is now day 9 is that the majority view is a high near or over the UK with an even chance of surface cold developing under a fairly calm and dry setup.It seems currently  the ECM suite are less keen and we may be looking at a flatter euro high with south westerlies across the north.   

Edited December 8, 2016 by phil nw.

[johnholmes]

31 minutes ago, KasimWeatherQuarnford said:

Off into phase 8, some members into phase 7, this also supportive of a pattern change say just before xmas 

 

be wary of this kind of deduction with low amplitudes

[mountain shadow]

4 minutes ago, johnholmes said:

be wary of this kind of deduction with low amplitudes

Indeed, but a move to zone 8 would be indicative of height rises in Mid Atlantic. Ok, maybe not a stellar Greenland block but perhaps an air flow North of West might be more probable.

[Scandinavian High.]

This has been showing consistent over last few runs run up to Christmas. And January.

Edited December 8, 2016 by abbie123

[bobbydog]

Third consecutive run where the GFS(P) wants to blow us away...

Might have to re-name it 'Dirty Harry'....

[frosty ground]

Quite a change is heights to our north and east at this point, Probably lead to nothing but it's noticeable.,

[Ravelin]

Quite a deference in heights to our north on the latest GFS run at day 5 compared to it's predecessor....

6Z   12Z

[frosty ground]

Undercut possible? 

[frosty ground]

UKMet pretty different! 

[Daniel*]

+ve heights a lot more amplified to the NE on this run surprised by the lack of comments. Return of continental winds SE'ly feeding into southern/eastern England chilly.

Edited December 8, 2016 by Changing Skies

[bobbydog]

7 minutes ago, Changing Skies said:

+ve heights a lot more amplified to the NE on this run surprised by the lack of comments. Return of continental winds SE'ly feeding into southern/eastern England chilly.

Everyone saw an attempt at a scandi high and hid behind the sofa.....

A tiny bit of undercutting and it could have been...

Edited December 8, 2016 by bobbydog

[Ravelin]

UKMO at t144 trying something similar to latest GFS?

 

Compared to 0Z ECM

Just too much chopping and changing from all the models to be sure  of much, as seems to have been the theme recently.