Model Output Discussion 29th December - Into mid-Winter.

[bluearmy]

I assume John is referring to the cold ridge coming off e Canada somewhere between day 7 and day 10.  I mentioned it this morning after the eps came out. if it's at day 7 on the GFS then they have certainly accelerated the pattern. Probably too much 

[SMU]

22 minutes ago, stewfox said:

Are you referring to this (circled) that was in 12z but not 6z ?

 

No mate hes referring to the -PNA ridge

here 

exiting canada !

 

[Scandinavian High.]

I need my snow fix the sledge has been in the shed for 5 years now anyway this looks good for some cold.

Edited January 1, 2017 by abbie123

[Guest]

2 minutes ago, Steve Murr said:

No mate hes referring to the -PNA ridge

here 

exiting canada !

 

heard much of this -PNA stuff the last week or so.. can somebody give me an idea of what i should be looking at when observing the charts and what it means in the NH and what effect it could have on us here in the UK? Many thanks...

[bluearmy]

1 minute ago, Steve Murr said:

No mate hes referring to the -PNA ridge

here 

exiting canada !

 

He said day 7? On reflection, I think the player is the ridge you marked and that also showed on th eps mean at day 10 this morning. If it verifies, it is our next route to amplification. The ridge earlier will not, I think be enough.

[stewfox]

2 minutes ago, More Snow said:

heard much of this -PNA stuff the last week or so.. can somebody give me an idea of what i should be looking at when observing the charts and what it means in the NH and what effect it could have on us here in the UK? Many thanks...

Yes maybe circle it for those wishing to learn

[johnholmes]

12 minutes ago, Steve Murr said:

No mate hes referring to the -PNA ridge

here 

exiting canada !

 

In answer to you Steve and to Stew=both really as one is unlikely without the other, chicken and egg perhaps but don't ask me to say which is which.

Other than the suggestion of December 2010 has anyone an idea what year this did happen please? It may have been Dec 2010 but that deep long lasting cold had been well sing posted by the anomaly charts and UK Met for two weeks or more before its onset in late November.

Edited January 1, 2017 by johnholmes

[knocker]

8 minutes ago, bluearmy said:

He said day 7? On reflection, I think the player is the ridge you marked and that also showed on th eps mean at day 10 this morning. If it verifies, it is our next route to amplification. The ridge earlier will not, I think be enough.

If that is the case, and I'm not sure John was referring to that ridge, then surely this is just next Atlantic wave and not a significant pattern change.... yet,

,

EDIT

Didn't see John's reply

Edited January 1, 2017 by knocker

[johnholmes]

39 minutes ago, BLAST FROM THE PAST said:

So the cold is off? No it isn't. Must be the MJO 

Scream trigger LP ...... one to watch

BFTP

How about a bit of solid info, positions lows/highs please? It would certainly help new folk better, even me with brain cells diminishing by the second!

[johnholmes]

I seem to have created a bit of an issue of just what it is and where.

Go to GFS N America and times 144 and 168h. Notice the ridge building as the low exits east.

Turn then to GFS N Atlantic version

At 120h you can see the low exiting the NE, by 168h the ridge is easily evident, as is the deepening surface centre close by SW Iceland. By 192h this is in to Sacnadinavia with the cold air well down across the UK with a mid Atlantic ridge.

The 192h time frame shows cold air well into the UK. 216h and this is even more evident.

However from then the ridge collapses ahead of the next Atlantic low.

What MAY happen is that the first low and ridging behind it MIGHT be the onset of a deep cold spell, say 3-4 days. I honestly do not know. Nothing in the anomaly charts really supports this idea, but then the anomaly charts are for overall upper air guidance for most instances.SOMETIMES after using them over a long time (several years!) they can give more guidance for low level features in the 6-14 day timescale. At the moment not this time is my assessment. But, as I said nitially it is worth watching the next 12z output to see if this pattern is shown again.

 

By the way a Very Happy New Year to everyone on the forum.

Edited January 1, 2017 by johnholmes

[beng]

15 minutes ago, johnholmes said:

 

Other than the suggestion of December 2010 has anyone an idea what year this did happen please? It may have been Dec 2010 but that deep long lasting cold had been well sing posted by the anomaly charts and UK Met for two weeks or more before its onset in late November.

From that description John, then it would definitely be Nov/Dec 2010 - I remember both the Met and the stratosphere boffins getting very excited before it all hit.

[ArHu3]

14 minutes ago, Dennis said:

The Netherlands has snow now - winter is still building

 

 

you must not have seen the latest ecmwf yet, it's bad, really bad

 

Edited January 1, 2017 by ArHu3

[bobbydog]

ECM and GFS quite different at 192

[knocker]

19 minutes ago, Dennis said:

The Netherlands has snow now - winter is still building

 

 

No major surprise regarding that. Pretty good forecast

Edited January 1, 2017 by knocker

[feb1991blizzard]

ECM GFS differences could be just a timing issue.

[January Snowstorm]

You have to say the longe range forecasts of blocking were v accurate.

Just for our minute islands this can still mean mild for us. I mean the cold spell hitting Eastern Europe is impressive.

I've held a thought for many years now that the Christmas period is key for what happens rest of Winter. No facts to back this up other than living through 40 plus years. Of course cold spells can still turn up in Jan/Feb.

Adapting a positive frame of mind for New years day we have plenty of Winter left to go and the latter half has proven to be the more fruitful over last 20 years.

[Dennis]

Just now, knocker said:

No major surprise regarding that

true but how long that was ..... so its a surprise in all those warm years in W Europe

[bobbydog]

7 minutes ago, ArHu3 said:

you must not have seen the latest ecmwf yet, it's bad, really bad

 

Is it? As far as I can see, its better that the 00z, the jet is further south and the HP to the south West is weaker and further west.

[keithlucky]

8 minutes ago, bobbydog said:

ECM and GFS quite different at 192

The met seems to agree with the GFS as forecasted to turn colder by the weekend.

[igloo]

4 minutes ago, ArHu3 said:

you must not have seen the latest ecmwf yet, it's bad, really bad

 

yes it does look like another atlantic ridge callapse leeding to another euro slug how often have we been here before this season its just not meant to be again this season just like the previous 3 sad

[January Snowstorm]

Just now, igloo said:

yes it does look like another atlantic ridge callapse leeding to another euro slug how often have we been here before this season its just not meant to be again this season just like the previous 3 sad

Every year attention is given to Northern blocking. Perhaps it's more important to try find out why these euro slug highs keep happening of late.

[karyo]

The 12z ECM say No to any quick road to cold! In fact, even the 240 hour chart is underwhelming.

[Tim Bland]

ECM at day 10 has "potential"  

how many times have you seen that written over the last few weeks ? 

Zzzzzzzzzzzzzzzz

[booferking]

Stick to the worst looking chart you wont be let down when the best wintery potential charts dont verfiy... Been here iv lost count how many times this Winter dont get dragged in not good for the health old yoyo head springs to mind.

ECM looks terrible with a capital T

Edited January 1, 2017 by booferking

[karlos1983]

Just now, karyo said:

The 12z ECM say No to any quick road to cold! In fact, even the 240 hour chart is underwhelming.

Yup quite a turn around in a few days. I'm still confident of a cold spell at some point though after mid month. Just a hunch.

not sure who it was that mentioned earlier about rarely seeing snow before mid January, but I can vouch for that, only a handful that I remember in my time.