Model Output Discussion - 05/01/2016 18z onwards

[Yorlum11]

Jma out to 84. To my untrained eye looks like the UKMO. Wider ridge and not as far west.

 

 

Edited January 8, 2016 by Yorlum11

[Ali1977]

A slow reversal to the charts of 2 days ago would be nice...could happen...

[Weather Boy]

9 minutes ago, abbie123456 said:

ukmo is on to something

 

Not sure why you say that, but if you are right, that would be a change from the last couple of years, where ukmo has said cold but has been dragged kicking and screaming into line by the other models.

But this time, the met seem to be going with it, so perhaps you are right.

[Paulmcc]

Hello there,1st time replying here,Been a avid reader of these post,Looking at the graphs tells me nothing as im still learning,Are we looking at a cold week next week or a mild one like what we have had.?

[Polar Maritime]

3 minutes ago, Paulmcc said:

Hello there,1st time replying here,Been a avid reader of these post,Looking at the graphs tells me nothing as im still learning,Are we looking at a cold week next week or a mild one like what we have had.?

Welcome Paul, Take a read back over the past few pages and all will be revealed. The models do continue to show a cold Northerly flow next week. Very uncertain into week 2.

Edited January 8, 2016 by Polar Maritime

[karlos1983]

12 minutes ago, Yorlum11 said:

Jma out to 120. To my untrained eye looks like the UKMO. Wider ridge and not as far west.

 

 

thats +84 not +120 i believe, which is as far as the JMA will go on the 06z

Edited January 8, 2016 by karlos1983

[Paulmcc]

Thank you PM,How do i learn to read these charts and where can i go to see them,So a nice cold spell on the way to our little Island next week.

[london and south east kent]

3 minutes ago, Paulmcc said:

Hello there,1st time replying here,Been a avid reader of these post,Looking at the graphs tells me nothing as im still learning,Are we looking at a cold week next week or a mild one like what we have had.?

going to get colder nextweek with frost and yes snow is in the forecast ...

[winterof79]

I do not see a great deal to be down about really.I have seen worse means at 240 considering

[Yorlum11]

7 minutes ago, karlos1983 said:

thats +84 not +120 i believe, which is as far as the JMA will go on the 06z

You are correct. Same still applies I suppose. Original post updated.

Edited January 8, 2016 by Yorlum11

[Polar Maritime]

5 minutes ago, Paulmcc said:

Thank you PM,How do i learn to read these charts and where can i go to see them,So a nice cold spell on the way to our little Island next week.

Take a look here and in the learning area Paul. Any other questions please ask in there, Thanks.

https://forum.netweather.tv/forum/5-the-netweather-guides/

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfs;sess=02c1ad30aefe378a3cbdef6d5abcbf9b

Edited January 8, 2016 by Polar Maritime

[summer blizzard]

The problem here seems the low near Newfoundland at day 7 and the GFS and Euro highlight two different ways it damages our pattern (though the Euro is not far off bringing a pressure build over Scandinavia). 

At day 7 both models are actually fine for a sustained cold pattern (see here that the low is just about negatively tilted on both models)..

 

 

However to address the GFS first, the problem here is that the low near Azores is weaker and slower moving and gets picked up by the primary low near Newfoundland, this pumps the Euro ridge and then we end up with a west based NAO as the trough over Newfoundland is replaced by a high and our trough gets anchored west of the UK a bit like this past week. The whole thing is a bit like attaching a ball to a piece of string, the primary low basically swings the Azores low north.

To address the Euro this morning it's actually not that bad, not as bad as it looks anyway and much easier to resolve. So the Azores low here is already stronger and been sped along by the sub-Tropical jet which means that although southern England get rained out, the north gets snow and the low has no impact on the long term pattern. The simple failure here is that the low near Newfoundland fails to remain negatively titled and ends up pumping a high close to the UK. This is much more a classic problem and more or less a simple issue of how much energy is going to end up in the Jet. 

 

So where do we go from here..

Well in the short term the route to cold from the GFS is clear in that we need a weak low around Newfoundland (which it has) but we also need a stronger Azores low that does not get caught. For the Euro we simply need the low around Newfoundland to be weaker however even if things transpire as forecast today then actually if we had a weaker low near the UK exiting further south and a secondary low from the low near Newfoundland we could easily that UK ridge become a Scandinavian one. 

I've not seen the ensembles yet but i suspect all is not lost.

 

[karlos1983]

1 minute ago, Yorlum11 said:

You are correct. Same still applies I suppose.

Yes, I would take the JMA 84 chart, good WAA into Greenland, and seems more akin to UKMO.

[Paulmcc]

Thank you to Abbie123456 and Polar Maritime for info.better get learning then.thank you again.

[Yarmy]

3 minutes ago, Paulmcc said:

Hello there,1st time replying here,Been a avid reader of these post,Looking at the graphs tells me nothing as im still learning,Are we looking at a cold week next week or a mild one like what we have had.?

It will be cold next week (exceptionally cold compared to what's gone before). Beyond that is a subject of considerable debate. The 3 main models are divided with ECM/GFS cutting off the cold feed early and the UKMO prolonging it (potentially: it only goes out to 6 days). It's fair to say there is a great deal of uncertainty, even in the short range.  

JMA looks close to this morning's Fax.

[terrier]

It does look like a big afternoon coming up on the models. Like mr murr has said what we don't want to see is a se cut off low on the models because it really is game over if that happens. Let's see what the gfs12z brings and the ecm and ukmo. 

[mountain shadow]

4 hours ago, bluearmy said:

The ecm parallel on the same page as the op but takes the snow line as far as the borders rather than Yorks/lancs day 8/9.

as Steve says, one of the main tipping points is quite early on near Greenland. You would think that the ops are going to be making the running

 

 

 

Or the ops detect a disturbance that they then need to do something with. The GFS consistently blows up low pressure more than it should.

Hopefully the 12s will bring some clarity.

[Paulmcc]

Just now, Yarmy said:

It will be cold next week (exceptionally cold compared to what's gone before). Beyond that is a subject of considerable debate. The 3 main models are divided with ECM/GFS cutting off the cold feed early and the UKMO prolonging it (potentially: it only goes out to 6 days). It's fair to say there is a great deal of uncertainty, even in the short range.  

JMA looks close to this morning's Fax.

Thank you Yarmy.

[radiohead]

CMA anyone?

[Shuga ice]

20 minutes ago, Paulmcc said:

Hello there,1st time replying here,Been a avid reader of these post,Looking at the graphs tells me nothing as im still learning,Are we looking at a cold week next week or a mild one like what we have had.?

It will turn colder next week but by no means a very cold or prolonged spell.  I would call it a cool dry spell with wintry showers, mainly on coasts and hills.

it will be warming up again the following week.

Edited January 8, 2016 by Shuga ice

[Snow Run]

1 hour ago, Severe Siberian icy blast said:

Going from experience , my take on this is , 

firstly the models pick up on the -NAO , and make them the over riding factor and brings freezing conditions to all...

Hi SSIB

I’m not sure if I’ve misinterpreted your comment, but this isn’t my understanding of the NAO. I may well be wrong, as my experience is from deterministic mathematical modelling of structures (FEA), as opposed to NWP. However, I’ve always understood that the NAO (and also AO, Arctic Oscillation) is a statistical index that shows how mean atmospheric pressure varies between two specific points, either current conditions or model output, ie it’s not a model input as a boundary condition.

So what I’m trying to say is that either a positive or negative NAO are something that the model output is indicating, and not something they would pick up on. For instance, if the model output is showing a Greenland HP and lower pressure further south, then the corresponding forecast NAO index for this would certainly be negative, but I don’t think that this model result would be fed back into the starting conditions in any way.

But I'm happy to be corrected!

[Frosty.]

6 minutes ago, Shuga ice said:

 

it will be warming up again the following week.

How do you know that?...there is uncertainty in the models beyond the cold spell next week, the cold could become entrenched. 

Edited January 8, 2016 by Frosty.

[Deep Snow please]

6 minutes ago, Shuga ice said:

It will turn colder next week but by no means a very cold or prolonged spell.  I would call it a cool dry spell with wintry showers, mainly on coasts and hills.

it will be warming up again the following week.

Given that the entire warming scenario is FI you seem very confident. There's every chance of the pattern become embedded. 

[Jimmyh]

6 minutes ago, Shuga ice said:

it will be warming up again the following week.

mild ramping, don't actually see in any of the outlooks post 10 days of anything like a warm up.....

 

 

[london and south east kent]

37 minutes ago, Weather Boy said:

Not sure why you say that, but if you are right, that would be a change from the last couple of years, where ukmo has said cold but has been dragged kicking and screaming into line by the other models.

But this time, the met seem to be going with it, so perhaps you are right.

just my take on things