Model Output Discussions 06z 04/11/16

[musician]

18 minutes ago, Seasonality said:

Yes, but I believe it became a bit of an in joke to call it a Stella run. The amusing misspelling was then turned into a riff on the 'pub run' as in Stella Artois

Ah! Sorry to be such a pedant!

[nick sussex]

5 minutes ago, blizzard81 said:

The ops are indeed terrible this morning. That by the way is not doom mongering. It is reading the models and saying how it is. What worries me most is the lack of cross polar flow in our direction on all the ops. You would think the ops would be the first to pick this up in the extended. Well, they were the first to pick it up - until this morning! What has changed? Can any of the experts on here give any clues?

Movement of the PV is causing the problem, that's in my non-expert soap star role! lol You need the main PV towards Siberia, generally the only route to cold with the main PV on the Canadian side is to get lucky with it orientating in a way to allow a Scandi high.

If you look back through the archives we've seen many a cold spell with an angry looking PV in Canada, we don't mind it looking angry but its where it sets up that's often caused the problems in recent winters.

 

Edited November 30, 2016 by nick sussex

[blizzard81]

3 minutes ago, nick sussex said:

Movement of the PV is causing the problem, that's in my non-expert soap star role! lol You need the main PV towards Siberia, generally the only route to cold with the main PV on the Canadian side is to get lucky with it orientating in a way to allow a Scandi high.

 

Lol, cheers for the reply Nick, much appreciated.

[Seasonality]

2 minutes ago, nick sussex said:

Movement of the PV is causing the problem, that's in my non-expert soap star role! lol You need the main PV towards Siberia, generally the only route to cold with the main PV on the Canadian side is to get lucky with it orientating in a way to allow a Scandi high.

 

Just to clarify Nick, where is it moving to that is different from yesterday's runs? Or is it that the movement is the same and the movement is causing the run to run volatility in the op output. Would be grateful for your insight.

[Frosty.]

17 minutes ago, nick sussex said:

Rather than try to spin things I'll be blunt the ops today are utter crxp for real cold!

 

I fear for your laptop Nick

Plenty of faux cold at least under high pressure showing on the 00z.

[booferking]

4 minutes ago, Seasonality said:

Just to clarify Nick, where is it moving to that is different from yesterday's runs? Or is it that the movement is the same and the movement is causing the run to run volatility in the op output. Would be grateful for your insight.

There is quite a big difference between last nights12z & this mornings 00z were the pv locates on the ECM.

We want it to go like last nights majority goes to Siberia.

Edited November 30, 2016 by booferking

[Summer Sun]

Pressure not dropping below 1025mb for at least another week on the mean

Longer term the mean still indicates things turning colder around mid month

[nick sussex]

1 minute ago, Seasonality said:

Just to clarify Nick, where is it moving to that is different from yesterday's runs? Or is it that the movement is the same and the movement is causing the run to run volatility in the op output. Would be grateful for your insight.

Its a bit like the chicken and the egg! lol Yesterday we saw the main PV located over in Siberia, today the models bring much of that west and its in relation to the different modelling of the Pacific ridge. A bit like Moses parting the Red Sea, Moses hasn't turned up today. Yesterday the PR carved its way through the pole and kept the main PV in Siberia.

We still see the Pacific Ridge today but its not forcing its way towards Greenland, it might just be a one off, we'll see what the outputs do for the rest of the day.

 

[Tim Bland]

If Steve M is reading I wonder if he still believes in his below prediction from last night after the overnight runs ? .....

" Therefor my forecast for the next 24-48 hours is for

0-72 minimal change

72-120 GFS to move to more negative tilted low in the atlantic & to show signs of developing the Iberian Low-Also ensemble suites pick the same signal up - perhaps tomorrow PM ( as this is todays 96-144 charts > tomorrows 72-120 )

144 onwards a high probability of the mild / flame ensembles evaporating ( for the second time this week ) to be replaced by an easterly flow of varying degrees of coldness - ranging from 0c - to maybe -8c

We will have to see whats the best possible cold flow we could tap although UKMO 144 looks almost best case out of a mediocre retrograde...

Moving past that - the hemisheric profile looks to get smashed by that huge pacific ridge - importantly the vortex needs to stay in the European or Eurasion quadrent- we DONT want it dropping west across into canada as that will stop any vortex split & cross polar ridge ! "

[MP-R]

Can we please please please ditch the notion of 'real cold' and 'faux cold'. Cold is cold and that's all there is to it. The only difference is whether it's snow making or not.

To my eyes, with the largely anticylonic theme continuing, more so for the south than north, there's plenty of cold on the table in the form of frost, ice, fog etc. much like today. FI is FI and I won't be believing raging easterlies or mushy southwesterlies until there is some consistency on board. Consistency at the moment is one of high pressure and chilly/cold conditions for the foreseeable.

All eyes on the 06Z rolling out shortly! 

[Seasonality]

9 minutes ago, nick sussex said:

Its a bit like the chicken and the egg! lol Yesterday we saw the main PV located over in Siberia, today the models bring much of that west and its in relation to the different modelling of the Pacific ridge. A bit like Moses parting the Red Sea, Moses hasn't turned up today. Yesterday the PR carved its way through the pole and kept the main PV in Siberia.

We still see the Pacific Ridge today but its not forcing its way towards Greenland, it might just be a one off, we'll see what the outputs do for the rest of the day.

 

Well from my limited understanding of NWP, I'm under the impression the models start with real time weather data reported from a particular timeframe which then 'model' where the weather could evolve from that particular point using various complex algorithms etc. So does that mean something must have been different in the data used to generate the overnight runs? I wonder what the fly in the ointment was? 

[warrenb]

Quite amusing, when all the agencies with Long Range forecasting tools have all been stating there will be a temporary warm up before blocking reasserts itself.

The models show exactly this, and the place is in depression. Patience is required, as I said yesterday, remarkable similarities to 1962, and we all know what happened then.

Reality check, go a look at the charts for early to mid December 1962.

[Seasonality]

Just now, warrenb said:

Quite amusing, when all the agencies with Long Range forecasting tools have all been stating there will be a temporary warm up before blocking reasserts itself.

The models show exactly this, and the place is in depression. Patience is required, as I said yesterday, remarkable similarities to 1962, and we all know what happened then.

Reality check, go a look at the charts for early to mid December 1962.

Well said that man. Do you have any insight as to when the evolution back to cold will start to become apparent?

[Weathizard]

2 minutes ago, MP-R said:

Can we please please please ditch the notion of 'real cold' and 'faux cold'. Cold is cold and that's all there is to it. The only difference is whether it's snow making or not.

To my eyes, with the largely anticylonic theme continuing, more so for the south than north, there's plenty of cold on the table in the form of frost, ice, fog etc. much like today. FI is FI and I won't be believing raging easterlies or mushy southwesterlies until there is some consistency on board. Consistency at the moment is one of high pressure and chilly/cold conditions for the foreseeable.

All eyes on the 06Z rolling out shortly! 

I don't actually use those terms but what's the issue with them? It helps less experienced members understand. It will feel bitingly cold under high pressure at this time of year but won't be cold enough for snow. (Pressure too high and uppers not sufficiently cold)

 

That aside, realistically we have taken a step back this morning but it was always going to be hard to replicate yesterday's UKMO, looking longer term(as usual... I know) things are looking interesting in the GEFS and long range outlooks so alas I will not be dismayed. We are in an infinitely better position than last year.

[warrenb]

1 minute ago, Seasonality said:

Well said that man. Do you have any insight as to when the evolution back to cold will start to become apparent?

No, but look at 1962, we went from mild SW'ly weather to block over us to easterly in the matter of a week.

Edited November 30, 2016 by warrenb

[terrier]

Well I think the output this morning isn't that bad plenty of cold underneath that high pressure. I think this winter could well be under the dry but cold theme. Plenty more model runs to come though between now and mid Dec. 

[Seasonality]

4 minutes ago, terrier said:

Well I think the output this morning isn't that bad plenty of cold underneath that high pressure. I think this winter could well be under the dry but cold theme. Plenty more model runs to come though between now and mid Dec. 

Yes, mid-December not even showing at ECM 240 stage yet and as is often stated here, the ECM 240 is often in chocolate teapot territory.

[jonboy]

It is not yet December!! The models will be up and down certainly in the longer range as they try and deal with atmospheric scenario's not seen for a long time. The big plus with what we have at present is what I like to call preparation weather. If we what snow etc to last when it arrives we need to have the ground cold enough so that we don't see instant melt. These cold frosty days etc are great preparation foe longer lasting snow cover when it arrives and it will

[MP-R]

11 minutes ago, Weathizard said:

I don't actually use those terms but what's the issue with them? It helps less experienced members understand. It will feel bitingly cold under high pressure at this time of year but won't be cold enough for snow. (Pressure too high and uppers not sufficiently cold)

 

That aside, realistically we have taken a step back this morning but it was always going to be hard to replicate yesterday's UKMO, looking longer term(as usual... I know) things are looking interesting in the GEFS and long range outlooks so alas I will not be dismayed. We are in an infinitely better position than last year.

I doesn't help though does it haha. I hadn't a clue what it meant when I first saw the term thrown about. The fact is the temperatures we're getting now are a lot colder than those we'd be getting from a snowy scenario, so really it should be a case of stating it will be cold and under high pressure. There's nothing faux about it at all.

The models are reminding me a little of the late December 2008 / January 2009 spell which was a prolonged dry and very frosty spell with a few ice days thrown in for good measure. 

[Frosty.]

All this talk of faux cold vs real cold, I imagine minus 9 celsius in parts of the south with severe frost and freezing fog this morning feels pretty real!

And with this set up!

Edited November 30, 2016 by Frosty.

[jvenge]

It probably got lost in the noise, but after yesterdays BBQ runs from the GFS, it looks to be keeping the UK at slightly below average now over the next 10 days or so. An improvement in that regard. Perhaps still too far out to see the signs of these changes that are talked about? 

I edited it after realizing I said this just before the 06z comes out. Let's hope that wasn't a foot in mouth comment :-)

Edited November 30, 2016 by jvenge

[bluearmy]

aI always find it better to refer to the kind of cold most are looking for on here as 'deep cold''

gives more of a feel for it being right through the trop rather than just the bottom few layers 

I think we will see a Canadian segmen form  (size prob dependent on how sustained the Pacific ridging is)  and the movement to that means anything other than a sausage high at a decent lat is tough to achieve whilst that Siberia to Canada energy movement takes place 

[Methuselah]

15 minutes ago, Frosty. said:

All this talk of faux cold vs real cold, I imagine minus 9 celsius in parts of the south with severe frost and freezing fog this morning feels pretty real!

And with this set up!

I'm not too bothered by the term, Frosty, apart from my dislike of francophone affectations...Why did I say that? Je ne sais pas pourquoi, exactement !

It does help newbies when I comes to understanding how temperature inversions work, however?

Edited November 30, 2016 by Ed Stone

[Frosty.]

10 minutes ago, Ed Stone said:

I'm not too bothered by the term, Frosty, apart from my dislike of francophone affectations...Why did I say that? Je ne sais pas pourquoi, exactement !

It does help newbies when I comes to understanding how temperature inversions work, however?

Agreed Ed..I mean Pete 

[gottolovethisweather]

23 minutes ago, Ed Stone said:

I'm not too bothered by the term, Frosty, apart from my dislike of francophone affectations...Why did I say that? Je ne sais pas pourquoi, exactement !

It does help newbies when I comes to understanding how temperature inversions work, however?

 

 

4

4

 

And those old hands as well, don't forget, Pete. Quite a rare event I imagine Frosty, yes. My question from yesterday remains unanswered. What other pointers should we looking for in the models other than the 850s should we be considering when looking for cold?

Edited November 30, 2016 by gottolovethisweather