Model Output Discussion 1st Nov.2013

[joggs]

Yep it would. Would love to see the following frames and ties in very nicely with the post Bluearmy made about interest around the 20th.

Sort of reminds me of the Dec 1990 bhart that.

[bluearmy]

just a note re NOAA cpc - they make the comment that the aleutian ridge seems certain and that teleconnections dictate a downstream east us trough. however, the nwp isnt showing that. they feel the nwp is unreliable at the moment if it doesnt have that trough. that should reduce confidence markedly in what we are seeing via week 2 output and perhaps more than ever, ens means and anomolys are the way for the time being. 

[winter snow]

then again scorcher your a mild fan and don't want cold weather but you got to remember we in last autumn now so have to accept that cold and snow going to have to start sometime. I agree with frosty that cold and wintery weather is maybe heading our way come just after mid month. am sure summer next year will be hot and sunny. anyway im going way of topic sorry mods. back to the models anyway.

[phil nw.]

Just a note re NOAA cpc - they make the comment that the aleutian ridge seems certain and that teleconnections dictate a downstream east us trough. however, the nwp isnt showing that. they feel the nwp is unreliable at the moment if it doesnt have that trough. that should reduce confidence markedly in what we are seeing via week 2 output and perhaps more than ever, ens means and anomolys are the way for the time being.

 

 

 

 

Yes a good point Nick.They also expressed doubts over the forecasted pattern yesterday too indicating uncertainty on zonality of the USA flow off the Pacific ridge.

 

Latest ECM anom day 10 still show a solid +ve height signal around the nw Atlantic

http://www.meteociel.fr/modeles/ecmwf/runs/2013110812/ECH101-240.GIF?08-0

 

Plenty of cold air lurking just to our north waiting .It's a case of seeing if the developing European trough digs far enough south to bring it this way. 

Edited November 8, 2013 by phil nw.

[Barry12]

Hopefully the GFS 18z keeps the trend going...

 

 

 

 

It does by the looks of it!

Edited November 8, 2013 by Barry95

[Average Joe]

As a newbie I'm totally confused some say maybe a cold shot mid November some argue no such thing , it's very confusing , some of the charts posted look ok for a cold spell then some don't I suppose it's just different people different opinions but It is very confusing . The only way that I definitely know if there's a true hint of a cold spell is when Mr Steve puts a post on ... Then I take notice !!

You'll get used to it! It took me a long, long time to work out what was going on, but eventually you get an idea as to who posts with cold/mild bias and who actually says what's going on within the models without any added bias. Gibby's summaries are a good starting point I'd suggest. Edited November 8, 2013 by DuncanK

[bluearmy]

naefs spreads remain consistent on the greeny/icelandic height rise in a fortnight. todays nuance is a west euro low anomoly, oft the missing ingredient to advect some cold across the uk.  we will see.

[Catacol]

Not seeing anything to excite me yet. ECM ensembles still show a strong Azores High presence with low pressure to our north. Greenland high not substantial enough to do anything decent to our west to east average and wet flow.

 

 

 

ECM op for the outer edges of reality is still very west to east

 

 

 

and while there are suggestions of height rises to our west this GFS image shows the high pressure being bent and literally blown away by the strength of the atlantic.

 

 

 

No - sorry folks. Occasional NW to N interludes as I suggested at the start of the month, but November is going to be dominated by the atlantic train.

 

We need something happening in the strat. Or we need a better tripole SST signature to support the atlantic high (currently that tripole looks to be fading...) or we need the sun to settle down. It is back up to high levels of activity today. Snow cover has dropped too out in Russia. None of this is good for high lat blocking.

 

Any straws? An outside chance of a CW... but I'm starting to get that sinking feeling that not much of note will happen until we see 2014 arrive, and even then we need an attack on the vortex to succeed.

[Tamara]

As a newbie I'm totally confused some say maybe a cold shot mid November some argue no such thing , it's very confusing , some of the charts posted look ok for a cold spell then some don't I suppose it's just different people different opinions but It is very confusing . The only way that I definitely know if there's a true hint of a cold spell is when Mr Steve puts a post on ... Then I take notice !!

Steve is a regular winter forum 'attraction' so worth reading his posts as well as some of the other regular experts on here who I know I always turn to for information to get some clue as to what may be going on.

 

Essentially, at least as I understand it, we are looking for an amplified pattern that turns the wind out of the south west and into the north west and gets some colder air southwards over the UK.

 

There is evidence to suggest this may happen later in the month

[AWD]

Latest ECM anom day 10 still show a solid +ve height signal around the nw Atlantichttp://www.meteociel.fr/modeles/ecmwf/runs/2013110812/ECH101-240.GIF?08-0

Worth noting the spread for the area though;EC mean, although definetly showing an amplified pattern, prefers a less progressively blocked pattern compared to the Op;Support is gathering for higher pressure to drift up from our SW, at first towards the UK turning things less unsettled the further south you are. This is in the medium timeframe and is supported well amongst most NWP suites;It's where the cell settles in the longer timeframe that will be critical to surface conditions for the UK into the second half of November. A multitude of options available, although a position somewhere to the west (be it W/NW/SW) is favoured more so currently. The Iceland GEFS show an increasing favouritism for a higher level of pressure there;As do the Iceland NAEFS suite;So support for the preferred NW route, but still one of many equally possible options. The NAEFS spread highlighting the greater than average uncertainty around the North Atlantic/Southern Greenland area;Although the anomaly guidance does, at least for now, show tentitive signs of a less active Atlantic pattern with something colder possibly evolving;The signs are definetly there for something a little more interesting for the cold lover, but it really is at a tentitive early stage currently. Looking at the 850hpa forecasts will be fruitless until we can get something a little more concrete regarding pressure distribution over the Atlantic region. I expect this won't be for a while though. In the more medium timeframe we do look like seeing something of a rise in pressure a little nearer to home, with something drier for the south inparticular in the offering.It's not uncommon for a settled spell to precede a colder spell. Could this be another example of this?

[damianslaw]

Reliable timeframe - very much more the same with the atlantic dominating. The azores high is trying desperately to ridge North into the mid atlantic but each time it looks like getting swamped by the atlantic trough.

 

Temperatures very much near average especially in the north with cooler shots at times here, but some milder shots for the south - Monday noticeably so.

 

Longer term - ECM continues to suggest more of a pronounced build of heights over the mid atlantic moving northwards with a scandi trough formation which would usher in a very cold arctic blast. as we enter the latter third of the month - still a long way off. GFS has toyed with this theme as well. I suspect the change being shown is due to the projected shift in the PV aided by the aluetian heights building into the pole. It is a very plausible synoptical evolution, but does not necessarily herald a marked change longer term from the current pattern.

 

The charts remind a little of this time in 2004 when we saw a notable potent arctic blast around the 18th - albeit shortlived.

[Severe Siberian icy blast]

Not seeing anything to excite me yet. ECM ensembles still show a strong Azores High presence with low pressure to our north. Greenland high not substantial enough to do anything decent to our west to east average and wet flow.

 

 

 

ECM op for the outer edges of reality is still very west to east

 

 

 

and while there are suggestions of height rises to our west this GFS image shows the high pressure being bent and literally blown away by the strength of the atlantic.

 

 

 

No - sorry folks. Occasional NW to N interludes as I suggested at the start of the month, but November is going to be dominated by the atlantic train.

 

We need something happening in the strat. Or we need a better tripole SST signature to support the atlantic high (currently that tripole looks to be fading...) or we need the sun to settle down. It is back up to high levels of activity today. Snow cover has dropped too out in Russia. None of this is good for high lat blocking.

 

Any straws? An outside chance of a CW... but I'm starting to get that sinking feeling that not much of note will happen until we see 2014 arrive, and even then we need an attack on the vortex to succeed.

Very sobering thoughts there.

The only thing I will say is we don't necessarily need the strat to act first disabling the vortex. The pacific ridge if strong enough increases wave activity into the strat which puts strain on the vortex. Infact if we can have a high pressure briefly in the right place to pump warm air into the poles which can have a knock on effect , inducing wave activity , and encourage northern blocking , not to mention mountain tourqe events that can happen and increase wave 2 into the strat .

[Frosty.]

Agreed tamara, I think there is even more evidence to support a cold spell for the final third of november than I saw yesterday.. Bring on the first cold spell asap. :- )

[Mair Snaw]

Not seeing anything to excite me yet. ECM ensembles still show a strong Azores High presence with low pressure to our north. Greenland high not substantial enough to do anything decent to our west to east average and wet flow.

 

 

 

ECM op for the outer edges of reality is still very west to east

 

 

 

and while there are suggestions of height rises to our west this GFS image shows the high pressure being bent and literally blown away by the strength of the atlantic.

 

 

 

No - sorry folks. Occasional NW to N interludes as I suggested at the start of the month, but November is going to be dominated by the atlantic train.

 

We need something happening in the strat. Or we need a better tripole SST signature to support the atlantic high (currently that tripole looks to be fading...) or we need the sun to settle down. It is back up to high levels of activity today. Snow cover has dropped too out in Russia. None of this is good for high lat blocking.

 

Any straws? An outside chance of a CW... but I'm starting to get that sinking feeling that not much of note will happen until we see 2014 arrive, and even then we need an attack on the vortex to succeed.

 

 

So your saying that from todays output you are already doing away with the first 4/5 weeks of winter?? and the rest of it by the look of things.... its gonna be a very long hard 4/5 months isnt it?? im sure i remember this time last year things being very much the same even worse after that failed ECM in December the amount of toys being thrown out of prams etc was silly....what happened from mid Jan onwards???? we have not even started winter yet and already its being binned.....when will some people learn...sorry rant over..

[Barry12]

Not bad

 

[Purga]

Agreed tamara, I think there is even more evidence to support a cold spell for the final third of november than I saw yesterday.. Bring on the first cold spell asap. :- )

I admire your confidence but every time the models seem to hint at something colder in FI they soon back track.

 

The above looks OKish but I'll bet the whole pattern will simply flatten out nearer the time.

 

BA & Co seem to have far more confidence in a cold outcome than Exeter do.

[Frosty.]

It can be like flipping a switch in november from mild to cold and my instinct and lots of charts I posted today says we will have a colder outbreak during the last ten days of the month.

[Cheshire Freeze]

I admire your confidence but every time the models seem to hint at something colder in FI they soon back track.

 

The above looks OKish but I'll bet the whole pattern will simply flatten out nearer the time.

 

BA & Co seem to have far more confidence in a cold outcome than Exeter do.

 

Look at the NH map for the same time as the chart you've posted there. No backtrack as far as I can see.

[Snowman.]

 

Quote:As a newbie I'm totally confused some say maybe a cold shot mid November some argue no such thing , it's very confusing , some of the charts posted look ok for a cold spell then some don't I suppose it's just different people different opinions but It is very confusing . The only way that I definitely know if there's a true hint of a cold spell is when Mr Steve puts a post on ... Then I take notice !!

It's the FI and current trends cold, however people calling mild are usually stating what the current run just produced.

 

 

 

 

We're not talking severe cold either, some decent frosts, MAYBE a wintry shower in the NE but nothing uncommon for the time of year.

Edited November 8, 2013 by SN0WM4N

[Geordiesnow]

Don't see any cold spells but I do see some cooler shots, starting this weekend in the North with the -5 hpa nearly touching Scotland. 

 

The outlook as we head into next week does look a very autuminal one, with quite a lot of windy weather interspersed with some cooler shots. Its a typical pattern of reletively dull with the more tropical mild airmass and in any polar one, it will be much brighter but showery in the West.

 

Not going to write this month off yet for perhaps the first potent cold shot of the season never mind writing the whole of December as one poster has done but there is no real signs of this occurring just yet so its a bit of a waiting game at the moment. 

[Snowman.]

 

No - sorry folks. Occasional NW to N interludes as I suggested at the start of the month, but November is going to be dominated by the atlantic train.

 

We need something happening in the strat. Or we need a better tripole SST signature to support the atlantic high (currently that tripole looks to be fading...) or we need the sun to settle down. It is back up to high levels of activity today. Snow cover has dropped too out in Russia. None of this is good for high lat blocking.

 

Any straws? An outside chance of a CW... but I'm starting to get that sinking feeling that not much of note will happen until we see 2014 arrive, and even then we need an attack on the vortex to succeed.

We don't need the strat, we have already been through this recently and we don't need it again.

 

The strat doesn't control NH weather patterns and in fact troposphere usually starts a warning in the first place.

 

We have had plenty of cold periods of weather with out the help from the strat, people tend to rely on it so much.

 

 

 

CFS has recently showed this stunner.

 

 

 

 

[Catacol]

So your saying that from todays output you are already doing away with the first 4/5 weeks of winter?? and the rest of it by the look of things.... its gonna be a very long hard 4/5 months isnt it?? im sure i remember this time last year things being very much the same even worse after that failed ECM in December the amount of toys being thrown out of prams etc was silly....what happened from mid Jan onwards???? we have not even started winter yet and already its being binned.....when will some people learn...sorry rant over..

 

Nope - I used a bit more than the output and once again no - I didnt throw any toys out... and in addition if you read what I said I declared that November looked flat and it was a suggestion that up until the New Year I was getting a sinking feeling. I didnt mention January and February at all.

 

And once again no - last year was different and I was one of those who was sure we were going to get the big easterly in December when the ensemble data was leaning so heavily to stalling lows and high lat blocking... but it didnt happen. I have no idea what you remember because it certainly wasnt the same kind of talk at all. The vortex was splitting as I remember - and so the signals were different.

 

I am a self confessed coldie, but will post what I see. You could do with reading what is put out a little more carefully before posting and perhaps taking a look yourself at background signals. Gavin Ps videos are quite good for this... or go read Chio's suggestions for the vortex this side of Xmas or perhaps RJS. 

 

The bin? Beyond November I didnt go near it.

Edited November 9, 2013 by Catacol_Highlander

[Catacol]

 

 

 

We have had plenty of cold periods of weather with out the help from the strat, people tend to rely on it so much.

 

 

 

 

Genuinely - can you show me an example since 2009? My own close following of NH weather goes back only that far, but I dont recall a single extended cold period that wasnt linked back to a strat event.

[bryan629]

whilst everyones attention is focussing on the will it be warm, will it be cold scenarios..... which the models are deliberating over and causing a bit of a stir in here, what will be will be ..... simply put the models are IMO onto some sort of pattern change as many may or may not agree with me... I am curious though scrolling through the pub run whats going on in the NH..

For example take a look at this from the GFS 12Z at +192 ....

 

The PV looks pretty much in tact and organised for what it should be at this time of year ....

A nice wrapped circular motion with the cold polar air pretty much contained

 

 

 

 

now take a look at the end of the GFS + 384

The PV is almost completely destroyed , the remnants are sent packing over to Siberia and cold polar air is leaking out all over the NH ...albeit over western Europe . what has caused this .... ??

 

 

 

 

 

 

 

 

[Catacol]

Don't see any cold spells but I do see some cooler shots, starting this weekend in the North with the -5 hpa nearly touching Scotland. 

 

The outlook as we head into next week does look a very autuminal one, with quite a lot of windy weather interspersed with some cooler shots. Its a typical pattern of reletively dull with the more tropical mild airmass and in any polar one, it will be much brighter but showery in the West.

 

Not going to write this month off yet for perhaps the first potent cold shot of the season never mind writing the whole of December as one poster has done but there is no real signs of this occurring just yet so its a bit of a waiting game at the moment. 

 

Agree with this. Cooler shots of a day or so - quite possible as the mid atlantic high comes and goes. Might see a potent day. But I'm past getting excited by a single day brought on by a toppler. 

 

I havent written December off yet but I would add that the majority of the longer range models are pointing towards late season cold and it looks a long shot now to see the tropospheric pattern slowed down sufficiently in the next 4 weeks to bring about an extended cold spell before Xmas. The trough over the UK may weaken as suggested by the Japanese model, but unless the aleutian high can throw a big spanner into the works and force a much more meridional pattern into action I am struggling to see a route to extended cold. 

 

I dont know enough about Canadian warmings yet... but it is a small straw I still have a finger in contact with. I have asked Chio about it over on the Strat thread but he seems to have gone very quiet. That isnt a great thing in itself because when he senses a warming, or reads one coming, he tends to post quite frequently. His silence to me is deafening.