Winter Model Discussion 18Z 19/1/13 onwards.

[winterof79]

Truly dreadful ECM FI charts as far as cold is concerned - if they were to verify we could be looking at 2-3 weeks of mild/average weather. The Polar Vortex is truly immense at 192/216.

The ECM shows the canadian lobe of the vortex shifting westward as has been stated for some time(GP/C).S/Westerlies will probably occur during the transition.

Thereafter heights should show signs of rising to our n/w.GFS has us back to cold as early as the 4th Feb http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=336&mode=1&carte=1

Once its finished its journey the vortex runs out of juice again and i suggest Feb will re-enter the freezer.I do not see 2/3 weeks of zonal .

[UV-RAY]

I disagree you seem to be looking at a glass empty and not half full.

There have been a few signs that after a breif reforming of the pv it looks to break up as we head into feb. ECM shows this to a extent in the later frames and a few previous op runs have been toying with the idea.

The suposed ssw that GP hints at has happened a few weeks back i believe but is yet to filter which could take up to a month which ties in with early Feb.

I expect a lot of stella fi to start in a day or two as the effects of the ssw start to filter into the op runs such like P10 on the gfs earlier on.

Fun times ahead i feel.

I would say he's only commenting on what is being shown, we can't comment on what isn't.

[bradymk]

Looking at the 192 hour chart from ECM can I ask how is it possible for the PV to be so dominant? I thought it was supposed to be dead and buried for quite some time.

Not pretty i know however all that has happened is the northern blocking as a result of the SSW is now forecast to happen on the pacific side rather than the atlantic side. Give it a few more days to a week and im expecting more eye candy charts to start showing up. Im going with around Feb 5th for a return to cold but we will see. Edited January 21, 2013 by bradythemole

[Yozzer]

This ECM run is enough to give you nightmares and probably night terrors to GP & CH!

Im getting a sense of deja vu at the moment from recent years and I hope this doesn't become true. What I mean by this is I recall last year I think, might be 2011, when we we're supposed to see epic blocking and quiet the reverse happened.

GEFS ensembles aren't really screaming a GH at the moment and the mean has actually dropped today.

http://cdn.nwstatic....mslReyjavic.png

I know GP said early Feb and that we might even see a cold spell develop as early as the 28th Jan. However at this stage this is looking incredibly unlikely especially starting at the 28th Jan. At the moment a long fetch of SW,lys is looking the likely outlook for the end of Jan.

But surely you, TEITS, more than most folk on here, don't expect T+240 to look like that chart? Winter forecasts have to be viewed as 'broad strokes' rather than specifics, and GP's forecast, to my mind, has been pretty reasonable so far. So has RJS's, both coming from different methodology. I normally respect your posts, but the last few have simply been having a dig at GP and Chio's long range musings. So, instead of doing that, why not 'have a bash' yourself? What's your take on the last 6 weeks of winter?

[Gibby]

Good evening. Here is my take on tonight's 12z output supplied by GFS, UKMO and ECM for today Monday January 21st 2013.

All models show the cold weather lasting several more days with a change at the start of the weekend to less cold and windy weather. through tonight and tomorrow a trough over the North weakens slowly with snow gradually dying down and eventually dying out altogether. In the South a quiet night seems likely before low pressure slips along the English Channel tomorrow with a mix of rain, sleet and snow a strong risk for Central Southern England and the SW later tomorrow. Through Wednesday to Friday the risk of snow subsides as a ridge of High pressure delivers a period of very frosty weather later in the week. Over the weekend all models show a breakdown as South to Southwest winds bring less cold conditions in from the West with a rapid thaw of lying snow and rain at times in strong winds.

GFS then shows next week to be increasingly mild but very unsettled with spells of rain and showers in strong SW winds in association of deep Low pressure out to the NW. Later in FI this pattern breaks as pressure builds over Greenland sending Low pressure SE over the UK and NW Europe bringing about a return of colder and more wintry potential late in the run in the wake of the depressions.

The GFS Ensembles show a strong signal for a warm up at the weekend with rain at times in association with Low pressure to the North or NW of Britain. This pattern then appears to continue then for the remainder of the run.

The Jet Stream currently running East over Southern Europe rises North towards the vicinity of the UK in a weeks time.

UKMO for noon on Sunday shows a very deep Low to the West of Scotland with a strong to gale West to Southwest airflow driving bands of rain quickly East over the UK followed by squally showers.

ECM too shows a similar pattern with Low pressure too out to the NW with a strong to gale and increasingly mild airflow over the UK next week with showers or longer spells of rain becoming more restricted towards the North and West by the end of the run as pressure rises to the SE.

In Summary the weather is set to change at the weekend. After a few more days of ice and snow the weather becomes dry and frosty for a period late in the week before a total change to relatively milder conditions with rain or showers at times affects all areas by the end of the weekend with very strong winds too.

[Frosty.]

It doesn't matter what the models are showing in FI right now, we know it's going to be turning milder over the weekend but where will we be synoptically on the first day of the milder spell, that will tell us a lot more and the next cold spell will probably be within T+144 range. As GP said before, the models had to react suddenly to the first downwelling wave and went from showing a mild mushy outlook to a sudden freeze, I feel the same will happen again and no matter how dross and mushy the outlook is tonight, it can and will change in the blink of an eye when the next downwelling wave hits, the models will be blindsided yet again. The meto are still keeping the cold will return in early to mid feb with temps dropping below average again either by the end of jan or start of feb, probably with the jet tilting nw/se after a mildish spell first half of next week.

[Jason M]

I disagree you seem to be looking at a glass empty and not half full.

There have been a few signs that after a breif reforming of the pv it looks to break up as we head into feb. ECM shows this to a extent in the later frames and a few previous op runs have been toying with the idea.

The suposed ssw that GP hints at has happened a few weeks back i believe but is yet to filter which could take up to a month which ties in with early Feb.

I expect a lot of stella fi to start in a day or two as the effects of the ssw start to filter into the op runs such like P10 on the gfs earlier on.

Fun times ahead i feel.

My concern is that amongst some on here there is a belief that because GP says there will be a cold spell then this must occur. With a few notable exceptions ie GEM and ensemble 10 of the GFS there is next to no meaningful evidence that this will occur. Indeed every set of runs is more zonal than the last.

GP may yet be proved right as we all know things can change but the combined efforts of just about every computer model available are pointing in the other direction tonight.

Obv this is no criticism of GP or anyone else for that matter but if GP could forecast with confidence every cold spell weeks ahead he would be earning millions per year. Unlike many who issue long range forecasts though GP does have logic and science behind his predictions which is better than 99 per cent of other forecasters on the Internet.

From today's output I see little to suggest HLB other than the odd rogue ensemble. In fact from today's output height rises to our south look more likely, which might signal prolonged zonality. Given the PV i really struggle to see how we will get pressure rises to our NW and the background signals this winter seem heavily against this for some reason. It's not fair, it doesn't fit with what we were expecting but that's life :-)

Anyway, Greenland heights by 10pm anyone :-)

Jason

[High Altitude]

On face value these two charts have a similar looking pattern:

http://www.wetterzentrale.de/archive/ra/1963/Rrea00119630108.gif

08 January 1963

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130121/12/24/h500slp.png

GFS 12z - 22 January 2013

However what interests me is the two low pressure systems on the GFS 12z coming across the Atlantic. Could these not promote WAA and reinforce our high as per the following days chart in 63:

http://www.wetterzentrale.de/archive/ra/1963/Rrea00119630109.gif

09 January 1963

Leading to this 2 days later:

http://www.wetterzentrale.de/archive/ra/1963/Rrea00119630111.gif

11 January 1963

And then:

http://www.wetterzentrale.de/archive/ra/1963/Rrea00119630113.gif

13 January 1963

A big turn around in just 4 days (96hrs). My point being that small changes early on can have huge implications further upstream. Not giving up our cold spell yet.....

Edited January 21, 2013 by High Altitude

[Paul White.]

Just a little bit of despondency in here anyone would think its 1988 outside (the year of the B**tlett) I think NS has the Tshirt. Honest if people expect falling snow within every town and city for half the month. Not only do I think they are deluded I actually think that they need to move out of the uk. In fact it might be best to leave the planet. Pluto on the outer edges of the solar system may satisfi people's expectations.. Last nights easterly delivered big time still is in the north east. So yes from an imby perspective I can't complain about this winter it really has had it all from record breaking rainfall to epic five hour blizzards. As for tonight's main models they show a mild zonal outlook at 140 to 240 hrs. But how many 240 hrs charts have come to fruition this winter? Even 144hrs charts are a struggle.

Paul

[Stuie]

On face value these two charts have a similar looking pattern:

http://www.wetterzen...00119630108.gif

08 January 1963

http://cdn.nwstatic..../24/h500slp.png

GFS 12z - 22 January 2013

However what interests me is the two low pressure systems on the GFS 12z coming across the Atlantic. Could these not promote WAA and reinforce our high as per the following days chart in 63:

http://www.netweathe...ction=gfs;sess=

09 January 1963

Leading to this 2 days later:

http://www.wetterzen...00119630111.gif

11 January 1963

And then:

http://www.wetterzen...00119630113.gif

13 January 1963

A big turn around in just 4 days (96hrs). My point being that small changes early on can have huge implications further upstream. Not giving up our cold spell yet.....

After watching the documentary at the weekend I thought about this. The part where the thaw came, everybody was relieved and then the cold came back worse than ever. Glad you posted this as it was a situation I thought to myself "could" happen when this spell has a milder period. (With potential modifications that the SSW could present)

[chris55]

On face value these two charts have a similar looking pattern:

http://www.wetterzen...00119630108.gif

08 January 1963

http://cdn.nwstatic..../24/h500slp.png

GFS 12z - 22 January 2013

However what interests me is the two low pressure systems on the GFS 12z coming across the Atlantic. Could these not promote WAA and reinforce our high as per the following days chart in 63:

http://www.wetterzen...00119630109.gif

09 January 1963

Leading to this 2 days later:

http://www.wetterzen...00119630111.gif

11 January 1963

And then:

http://www.wetterzen...00119630113.gif

13 January 1963

A big turn around in just 4 days (96hrs). My point being that small changes early on can have huge implications further upstream. Not giving up our cold spell yet.....

Just a little heads up, may be helpful.

To post an individual chart, rather than linking to the page,

If your on IE, right click image, go to properties, copy URL and paste that link, or put it in picture box when composing post.

On Chrome, right click image, choose "open image in new tab" copy address from address bar (URL) and post that link

Not sure about Firefox etc.

EDIT, scrap that, strangely all links worked fine on the quoted post, but not on the original, v strange

Edited January 21, 2013 by chris55

[london-snow]

My concern is that amongst some on here there is a belief that because GP says there will be a cold spell then this must occur. With a few notable exceptions ie GEM and ensemble 10 of the GFS there is next to no meaningful evidence that this will occur. Indeed every set of runs is more zonal than the last.

GP may yet be proved right as we all know things can change but the combined efforts of just about every computer model available are pointing in the other direction tonight.

Obv this is no criticism of GP or anyone else for that matter but if GP could forecast with confidence every cold spell weeks ahead he would be earning millions per year. Unlike many who issue long range forecasts though GP does have logic and science behind his predictions which is better than 99 per cent of other forecasters on the Internet.

From today's output I see little to suggest HLB other than the odd rogue ensemble. In fact from today's output height rises to our south look more likely, which might signal prolonged zonality. Given the PV i really struggle to see how we will get pressure rises to our NW and the background signals this winter seem heavily against this for some reason. It's not fair, it doesn't fit with what we were expecting but that's life :-)

Anyway, Greenland heights by 10pm anyone :-)

Jason

The fact remains GP predicted a cold feb months ago. However the most encouraging is the fact that he still going for the same at this point just around the corner. GP strikes me as a level headed guy & that if his previous thoughts are not inline with what is showing he strikes me as a person that will admit to it instead of getting peoples hopes up.

[weatherguy]

On face value these two charts have a similar looking pattern:

http://www.wetterzen...00119630108.gif

08 January 1963

http://cdn.nwstatic..../24/h500slp.png

GFS 12z - 22 January 2013

However what interests me is the two low pressure systems on the GFS 12z coming across the Atlantic. Could these not promote WAA and reinforce our high as per the following days chart in 63:

http://www.wetterzen...00119630109.gif

09 January 1963

Leading to this 2 days later:

http://www.wetterzen...00119630111.gif

11 January 1963

And then:

http://www.wetterzen...00119630113.gif

13 January 1963

A big turn around in just 4 days (96hrs). My point being that small changes early on can have huge implications further upstream. Not giving up our cold spell yet.....

The major/key difference is that in 1963 that LP system out to the west was far far further south than the one shown for tomorrow's chart.

[gaia rules]

Could that monster low forecast by ECMWF GFS and UKMO break any records? With my glasses i make that a central pressure of 920mb!

[High Altitude]

Just a little heads up, may be helpful.

To post an individual chart, rather than linking to the page,

If your on IE, right click image, go to properties, copy URL and paste that link, or put it in picture box when composing post.

On Chrome, right click image, choose "open image in new tab" copy address from address bar (URL) and post that link

Not sure about Firefox etc.

EDIT, scrap that, strangely all links worked fine on the quoted post, but not on the original, v strange

On iPad. Any suggestions much appreciated. Will try repost with direct links.

[High Altitude]

The major/key difference is that in 1963 that LP system out to the west was far far further south than the one shown for tomorrow's chart.

That's true, but would the strength of that low not compensate for this and as opposed to being our precursor to mild actually be the trigger we need to sustain cold spell?

[lorenzo]

Could that monster low forecast by ECMWF GFS and UKMO break any records? With my glasses i make that a central pressure of 920mb!

I asked the very same question today, got sent this and advice that this would rank as the 3rd deepest LP system since 1979 in the Atlantic. An event in itself !

[Jason M]

The fact remains GP predicted a cold feb months ago. However the most encouraging is the fact that he still going for the same at this point just around the corner. GP strikes me as a level headed guy & that if his previous thoughts are not inline with what is showing he strikes me as a person that will admit to it instead of getting peoples hopes up.

Yep, I agree with all of that. But to just assume that there is a cold spell coming because GP thinks so is to court disappointment and is actually unfair to the man himself.

Since posting I've looked the GEM ensembles and they absolutely scream heights from the south, as do the GFS ensembles as does ECM, NOGAPS etc etc, yet people are talking about HLB.

Still, no forecast is right or wrong until after the event so time will tell. All I'm saying is that people need to view GPs forecast in the correct context.

The main hope that I can see is that the models will pick up on a major pressure rise over Scandi at say day 4. It's a real long shot but frankly IMHO if we get to where we are expected to be at day 5, were going zonal :-(

Jason

[Southern Storm]

Yes its looking increasingly likely that we are gonna enter a milder and more mobile pattern as we go into next week

But most of the country is still under snow with more falls possible! Get outside and enjoy it while its still there.

But It always makes me laugh when people get hung up with every model run, when you only need to look

Back to last week to see how fast things can change at short notice, and so what if it gets warmer, who can 100%

say its gonna last the rest of winter?

Also somthing i think needs to be said.

A few people on this forum are very quick to rubbish Gp's and Chino's ideas (not to mention many other posters on here) and take almost every opportunity to point out when things haven't gone to plan.

well next year I hope people who obviously know Better have the courage to put out a long range forecast and spread their wealth of knowledge and forecasting abilities with us all!

Edited January 21, 2013 by thunderman24

[mcweather]

My concern is that amongst some on here there is a belief that because GP says there will be a cold spell then this must occur. With a few notable exceptions ie GEM and ensemble 10 of the GFS there is next to no meaningful evidence that this will occur. Indeed every set of runs is more zonal than the last.

GP may yet be proved right as we all know things can change but the combined efforts of just about every computer model available are pointing in the other direction tonight.

Obv this is no criticism of GP or anyone else for that matter but if GP could forecast with confidence every cold spell weeks ahead he would be earning millions per year. Unlike many who issue long range forecasts though GP does have logic and science behind his predictions which is better than 99 per cent of other forecasters on the Internet.

From today's output I see little to suggest HLB other than the odd rogue ensemble. In fact from today's output height rises to our south look more likely, which might signal prolonged zonality. Given the PV i really struggle to see how we will get pressure rises to our NW and the background signals this winter seem heavily against this for some reason. It's not fair, it doesn't fit with what we were expecting but that's life :-)

Anyway, Greenland heights by 10pm anyone :-)

Jason

Hi Jason

While us coldies are all impatient to see the signs in the modelling of the next cold phase forecast by GP.

It is worth picking out this paragraph from his update in the in depth technical thread last night.

''So teleconnectively we have a reasoned case for anomalous heights to our north end January into February. The timing of this highly problematic as the models were to a degree blind-sided by the first downwelling wave, only latching onto it 2 days before the warming took place. Were this happen again, a sudden turnaround in modelling could well occur.''

[Snowman.]

Yep, I agree with all of that. But to just assume that there is a cold spell coming because GP thinks so is to court disappointment and is actually unfair to the man himself.

Since posting I've looked the GEM ensembles and they absolutely scream heights from the south, as do the GFS ensembles as does ECM, NOGAPS etc etc, yet people are talking about HLB.

Still, no forecast is right or wrong until after the event so time will tell. All I'm saying is that people need to view GPs forecast in the correct context.

The main hope that I can see is that the models will pick up on a major pressure rise over Scandi at say day 4. It's a real long shot but frankly IMHO if we get to where we are expected to be at day 5, were going zonal :-(

Jason

That monster low is most of the energy from the PV being sent east.

[Jason M]

Hi Jason

While us coldies are all impatient to see the signs in the modelling of the next cold phase forecast by GP.

It is worth picking out this paragraph from his update in the in depth technical thread last night.

''So teleconnectively we have a reasoned case for anomalous heights to our north end January into February. The timing of this highly problematic as the models were to a degree blind-sided by the first downwelling wave, only latching onto it 2 days before the warming took place. Were this happen again, a sudden turnaround in modelling could well occur.''

Count me amongst the coldies :-)

I understand the point but as TEITs implied where is this reflected in the models?

Anyway, enough on this subject I think (sorry mods). Onwards to the 18z run.

Jason.

Edit good debate in here tonight. This thread has really matured this year IMHO

Edited January 21, 2013 by Jason M

[bluearmy]

Gem runs at quite high res for the first 2 or 3 days and then drops to ukmo post T72 resolution levels. Unless gem is finding something in the first few days that sets it apart from all the other ops re undercutting at day 6, i think it safe to assume it wont look like that tomorrow. i was waiting for todays ukmo 12z before dismissing the modelling being likely to u turn. Given that this model was the leader at spotting the undercut last week, i was prepared to give it a last chance today to head that way. Alas, it didnt

It should be interesting to watch the modelling over the next couple of days. The low to our west will not be as deep as currently shown. The jet streak may ot be as strong. Just how much energy is going to be required to knock what will be quite a 'heavy ' cold ridge over?

[Jaffusmaximus]

Could that monster low forecast by ECMWF GFS and UKMO break any records? With my glasses i make that a central pressure of 920mb!

Will here is an Irish History lesson about the Oiche Gaoithe Mor (Night of the Big Wind) Jan 1839

"The storm attained a very low barometric pressure of 918hectopascals (27.1 inHg) and tracked eastwards to the north of Ireland, bringing winds gusts of over 100 knots (185 km/h, 115 mph) to the south before moving across the north of England and onto the European continent where it eventually died out. At the time, it was the most damaging Irish storm for 300 years."

http://en.wikipedia.org/wiki/Night_of_the_Big_Wind

Edited January 21, 2013 by Jaffusmaximus

[surrey slush]

Ok, I simply don't have enough information to make a call on what the weather will do 28th+.

But what should we be looking for in the models in the next few days to help us pick a horse?

To my mind I'm not even looking for a GH @ 200hrs+, what I'm looking for first is ens support for whatever the OP run of the day is showing to break down, as seen prior to the the current event. It is painfully clear the the current models really can't deal with SSW downwellings.

I'm not too disheartened by zonal models off into lalaland, but the good inter and intra model agreement is a bit worrying.

The coldie in me is saying, even the comedy models can model a breakdown, and things like 920mb lows say things are afoot that just haven't been anticipated by the models, which by their very nature will always tend to the mean.

What auguries do more seasoned members think we should be looking for in the steaming guts of the models?