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Model Output Discussion - 19th - 25th December


reef

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Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

still a significant clustering showing a block to our west day 10 (not dissimilar to the op GEM run).

(and i note more runs going cold in holland beyond - though not a trend as yet)

assuming that most of us are in agreement that the op runs are not the best tool for looking at the period days 8 through 10, why do we take too much notice of the meteopsu output which is a mean representation of both the ecm and gfs op runs, days 8 thru 10. ????

straw to clutch ? at the very end of the 00z naefs run we see a clustering of heights rising just se of greenland. not a transient ridge shape either.

I can understand the enthusiam for the strato warming, but as even Chino confesses there is no guarantee that the warming will work down to the tropo and that we may be pinning too much hope on this bringing what we all want - cold and snow.

I'd rather keep track of what models are showing, including the 8-10day H500 comparisons, and spot any trends than rely solely on ensembles as guidance, as equally they can change at a whim just like the operationals!

Of course it is interesting to spot stratospheric temperature trends, but no point getting everyones hopes up when it may not pan out.

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Posted
  • Location: Thornaby-on-Tees
  • Weather Preferences: Snow Showers, Snowy Periods , Blizzards, Cold Weather
  • Location: Thornaby-on-Tees

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzen...s/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

looks cool till wednesday then mild for a few days then cooler again on friday and things are looking up in the strato thread so maybe first half of jan will deliver in particular the 2nd week could be quite juicy but thats a long way off

Edited by chionomaniac
removed off topic comment
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Posted
  • Location: st albans
  • Location: st albans

I can understand the enthusiam for the strato warming, but as even Chino confesses there is no guarantee that the warming will work down to the tropo and that we may be pinning too much hope on this bringing what we all want - cold and snow.

I'd rather keep track of what models are showing, including the 8-10day H500 comparisons, and spot any trends than rely solely on ensembles as guidance, as equally they can change at a whim just like the operationals!

Of course it is interesting to spot stratospheric temperature trends, but no point getting everyones hopes up when it may not pan out.

Nick - i dont think i have mentioned the possible strat warming in any recent posts ?? i am referring to the model output, just like yourself. wrt to your second sentance, i am far happier consulting the ens and spreads than the op mean height anomoly chart. much less chance of flipping on the ens output in the longer range than with the ops.

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Posted
  • Location: Runcorn, Cheshire
  • Weather Preferences: Snowy winters, hot, sunny springs and summers.
  • Location: Runcorn, Cheshire

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzen...s/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

What I don't understand is, if it's so easy to get to this kind of set up, why would it be so hard to go back?

Sure we have a cold stratosphere and a raging PV, but I don't understand really.

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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzen...s/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

And ECM makes a good job up until the same point of squashing old Uncle Barty..

http://www.wetterzentrale.de/pics/Recm2401.gif

As OMM has provided analog for, this ridge can quickly transfer to heights over Greenland and then change the pattern very quickly.

Is there anything that convinces you that the GFS 240 pattern will remain like that for long haul?

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington
Posted · Hidden by chionomaniac, December 19, 2011 - off topic
Hidden by chionomaniac, December 19, 2011 - off topic

Saw this on TWO

http://cmdp.ncc.cma....209GLZ500L7.GIF

Hot summer anyone from July to September 2012? The Beijing model say's so.

:clap::good:

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Posted
  • Location: Chelmsford
  • Weather Preferences: Hot and dry summers with big thunderstorms.
  • Location: Chelmsford

What is concerning about this model discussion is that like the summer where everyone was waiting for a ridge to develop to our east. The same is happening this winter with the SSW. I'm not saying it will or won't happen! But even if it does as some have pointed out, it doesn't directly mean a big Greenland high and extreme cold! My advice would be to take a look at trends developing and particularly whether a ridge is likely to develop to our west/northwest, other factors also need to be considered.

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Posted
  • Location: London, UK
  • Weather Preferences: MCC/MCS Thunderstorms
  • Location: London, UK

What is concerning about this model discussion is that like the summer where everyone was waiting for a ridge to develop to our east. The same is happening this winter with the SSW. I'm not saying it will or won't happen! But even if it does as some have pointed out, it doesn't directly mean a big Greenland high and extreme cold! My advice would be to take a look at trends developing and particularly whether a ridge is likely to develop to our west/northwest, other factors also need to be considered.

You saying we could get as high as low 20s in such a setup, that would be fantastic for summer in winter? I understand thats sort of what you mean.

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Posted
  • Location: Cleeve, North Somerset
  • Weather Preferences: Continental winters & summers.
  • Location: Cleeve, North Somerset

Utterly diabolical models today. The GFS showing weak zonality for the next week or so with FI producing something more anticyclonic with surface cool/cold at best. Really need to get rid of that PV or at least shunt it eastwards towards Russia which the models were hinting at a few times last week.

I think I'm going to test the theory of evading the models for a few days and see if anything has changed in a few days time.

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Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzen...s/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

It looks very much that way Ian, as does your very mild pre Xmas week, at least much of it. No denying either that the 240hr is the stuff nightmares are made of, with mild air blasting through towards the Urals a day or two later, but I'm not convinced we'll ever get there. I think the most likely evolution post Xmas is for HP to build over the UK behind a weak CF and although mild zonality may return to the north for a while I expect the south to settle down, with the drier weather edging north as we approach New Year. At this point I'd like to think the jet will buckle sufficiently to allow pressure to build over Scandi and link to our cell, eventually introducing an Easterly (but by no means a Beasterly) to the south, but whether we can build heights far enough north to get a shot at some proper cold remains uncertain to my mind. I'm increasingly inclinded to think we won't and the Atlantic will be back.... but it's all a long way off as things currently stand for sure.

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Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

I think I'm going to test the theory of evading the models for a few days and see if anything has changed in a few days time.

Not within t144 they won't very much. Come back after Xmas Day.

BFTP

Edited by IanM
pointless, and not model related
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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

The latest models show temps back to average tomorrow but mild on wed/thurs before falling back to average on friday and then turning milder again for xmas eve/day but possibly a bit colder in the days following christmas so the temps will be up and down but nowhere near as cold as it has been and currently is in the east. It also looks like most of the rain in the next 7-10 days will be across nw britain and windy at times but milder than of late apart from very brief incursions of polar maritime air but for southern areas it looks generally milder and less unsettled for much of the time with above average temps and some sunshine but frosts fairly limited unless the anticyclone pushes further into the south of the uk which has ensemble support, the azores high does look like pushing east into mainland europe but with low pressure(s) to the north of the uk, we will have a nw/se or n/s split for some time to come.

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Posted
  • Location: G.Manchester
  • Location: G.Manchester
Posted (edited) · Hidden by IanM, December 19, 2011 - removed quoted comment
Hidden by IanM, December 19, 2011 - removed quoted comment

That isn't a very mild pre-christmas week, sorry but that has to be said.

BFTP

I suppose the models sum up this year in a nutshell really. Nothing exciting just typical mild British weather with high pressure dominating towards the south east dragging in mild southwesterly winds from the azores this side and after the 25th. Mildest weather probably towards the north. The south may see some kind of cloudy inversion.

Edited by IanM
removed unnecessary comment
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Posted
  • Location: ILCHESTER
  • Location: ILCHESTER
Posted (edited) · Hidden by IanM, December 19, 2011 - removed quoted comment
Hidden by IanM, December 19, 2011 - removed quoted comment
And that was supposed to happen early dec, then Mid, then leading up to christmas and now the 29th. Hmmmmm :huh: Confidence must have been knocked somewhat. Shed, you say it very much looks that way along with the very mild pre Christmas week then go onto say that you don't think we'll get there? And just watched BBC forecast, cold today, 5-7c tomorrow, 10-11c Wed/ Thurs then cooling down from NW on Fri. That isn't a very mild pre-christmas week, sorry but that has to be said.

BFTP Not within t144 they won't very much.

Come back after Xmas Day. BFTP

I think you are rather splitting hairs here Blast to be fair. I think most would conclude that given average maxima of 4-7c north to south in the last 3rd of Dec, Weds and Thursday this week will be very mild. I can see many places getting 10-12c and some favoured areas 13c given any sunshine. 4-6c above average is very mild to my mind, irrespective of what the MO say, either with regard to midweek or temps of 4-6c above average in Winter generally.

Edited by shedhead
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Posted
  • Location: West Sussex
  • Weather Preferences: Outdoors
  • Location: West Sussex

A quick reminder, this is the model discussion thread, not the BBC forecast says thread, or the point scoring against other members thread, thanks

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Posted
  • Location: Lincoln, Lincolnshire
  • Weather Preferences: Sunshine, convective precipitation, snow, thunderstorms, "episodic" months.
  • Location: Lincoln, Lincolnshire

Average late-December maxima at low levels typically range between 5-6C in northeast Scotland and 8C in parts of southern and southwestern England. Mean minima range between 0 and 3C across much of the country. By this measure, it certainly won't be particularly mild until Christmas Eve, with temperatures merely recovering to near-average values between now and the 23rd due to a couple of chilly north-westerly incursions.

From Christmas Eve onwards, though, temperatures look set to rise somewhat above the seasonal average with most places getting into double figures- sometimes the odd 13 or 14C ends up being registered in eastern Scotland and NE England in these situations due to the fohn effect. High pressure is set to move into Europe, giving rise to the possibility of a true "Bartlett" high sticking around Europe for a while and giving us persistent south-westerlies, though as the ECMWF extended output illustrates, it could also turn out to be a temporary breakaway high from the Azores which retreats eastwards allowing a cooler zonal regime in. At present NOAA appear to be siding more with GFS in their 8-14 day outlook prediction:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

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Posted
  • Location: Hexhamshire
  • Location: Hexhamshire

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzen...s/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

True but not impossible, 11th Jan 2009 attached, 3 weeks later was a very different picture.!!!!

The start of the end of the M.E.

post-2312-0-27447800-1324303583_thumb.gi

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Posted
  • Location: Maddiston , Falkirk, Scotland 390ft above sea level
  • Location: Maddiston , Falkirk, Scotland 390ft above sea level

True but not impossible, 11th Jan 2009 attached, 3 weeks later was a very different picture.!!!!

The start of the end of the M.E.

That's grim reading!
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

Just a touch of reality-been away a day or so, for those using comparisons. Take a look at, someone showed a chart in Jan 1947 a day or so ago. Then look 72 hours ahead!

The weather can AND does, as all saw last week, make many of us who profess to be able to forecast it, using whatever method turns us on, look pretty foolish at times.

I have no idea what the NAO, AO, MJO, Startosphereic profiles etc were before the 1947 freeze up started or indeed another winter I 'enjoyed' 1962-63 but the weather does sometimes change very rapidly. Don't be taken in too much by any of us telling you what is going to happen-it might turn out right it might not. But providing folk use charts to illustrate their belief I think its fine, be it a forecast for tomorrow or a month ahead. What probably irks other folk as much as myself are those posts with little if any chart evidence or links to explain their forecast.

For what its worth the 500mb anomaly charts still show pretty much what they have shown over the past 7-10 days for 10-15 days ahead. A strongish westerly flow across the Atlantic into the UK, sometimes, as those of the last 24 hours show, suggesting a flow from about 240 degrees sometimes about 270 degrees. Most of the time with the heights between 534 and 546DM over central UK. This suggests much as we have had over the past 7-10 days.

Really the Met O 6-15 and their 16-30 day outlooks pretty well mirror this and are about as close as any of us are likely to be to what the actual weather will be.

Edited by johnholmes
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Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey
Posted (edited) · Hidden by Osbourne One-Nil, December 19, 2011 - Not model related. if you've a technical problem, please PM one of us. For the record btw, John isn't one of the team, so is under no obligation to help provide consistency!
Hidden by Osbourne One-Nil, December 19, 2011 - Not model related. if you've a technical problem, please PM one of us. For the record btw, John isn't one of the team, so is under no obligation to help provide consistency!

. Don't be taken in too much by any of us telling you what is going to happen-it might turn out right it might not. But providing folk use charts to illustrate their belief I think its fine, be it a forecast for tomorrow or a month ahead. What probably irks other folk as much as myself are those posts with little if any chart evidence or links to explain their forecast.

So if someone can't post links or charts as 'evidence', due to computer issues which haven't been resolved, then they should be banned from the topic? If one can't mention BBC forecasts which refer to charts that one would wish to post then what else should they say?

A westerly flow dominating but mixed temps over next 5 days bringing overall average temps as we see mixture of NW/SW and Westerly winds and NOT very mild all week as IMO incorrectly suggested. Why on earth is that removed from a post? ECM and near time GFS agree with that, please mods feel free to consign this to the garbage bin as well, but show some consistency.

BFTP

Edited by BLAST FROM THE PAST
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Posted
  • Location: Dublin, ireland
  • Weather Preferences: Snow , thunderstorms and wind
  • Location: Dublin, ireland

Just a touch of reality-been away a day or so, for those using comparisons. Take a look at, someone showed a chart in Jan 1947 a day or so ago. Then look 72 hours ahead!

The weather can AND does, as all saw last week, make many of us who profess to be able to forecast it, using whatever method turns us on, look pretty foolish at times.

I have no idea what the NAO, AO, MJO, Startosphereic profiles etc were before the 1947 freeze up started or indeed another winter I 'enjoyed' 1962-63 but the weather does sometimes change very rapidly. Don't be taken in too much by any of us telling you what is going to happen-it might turn out right it might not. But providing folk use charts to illustrate their belief I think its fine, be it a forecast for tomorrow or a month ahead. What probably irks other folk as much as myself are those posts with little if any chart evidence or links to explain their forecast.

For what its worth the 500mb anomaly charts still show pretty much what they have shown over the past 7-10 days for 10-15 days ahead. A strongish westerly flow across the Atlantic into the UK, sometimes, as those of the last 24 hours show, suggesting a flow from about 240 degrees sometimes about 270 degrees. Most of the time with the heights between 534 and 546DM over central UK. This suggests much as we have had over the past 7-10 days.

Really the Met O 6-15 and their 16-30 day outlooks pretty well mirror this and are about as close as any of us are likely to be to what the actual weather will be.

I certainly remember the charts of early Jan 1982 and it was only possible to see about 3 days ahead at the time and no weather nurds like me to exchange views on forums.

The sudden change then and the mystery of not knowing too far ahead made the end result all the more exciting. I do miss those days.

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Posted
  • Location: Pembrokeshire
  • Weather Preferences: Snow
  • Location: Pembrokeshire

Well we are now facing up to an intense PV and Uncle Barty;

http://www.wetterzentrale.de/pics/Rtavn2401.png

Get to here, and it's a long haul back to even the sort of cooler zonality seen lately

It is more sensible to look for short term trends rather than making a statement on a chart that has a very low probability of verifying - same old story every year!

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

A green christmas and new year are more or less guaranteed now with a tropical maritime flow covering at least the south of the uk, again there is a chance of the high to the south building into southern areas and bringing the twin hazards of fog and frost but if the flow remains moderate or fresh from a predominantly sw'ly quarter, it will remain either mild or very mild over christmas with temps of 12-14c possible, probably a bit cooler in the north with a flow from the north atlantic keeping temps nearer to 8-10c for most of the time but the northern third of the uk probably remaining generally unsettled with spells of rain and stronger winds with a few brighter, colder and showery interludes.

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Posted
  • Location: Morecambe
  • Location: Morecambe

I think cold fans will need to have a bit of paitence regarding the upcoming weather but thankfully with xmas coming up, the weather will probably not be on most peoples minds as much if it was in January or earlier on in the season.

The outlook is not a totally mild dominated outlook, if we can get the jet to buckle then we should see some cooler weather with wintry showers in the NW like what is forecast for Friday however the models are hinting at a Euro high set up and with a fairly strong PV in control then it may be a struggle to get much in the way of cold weather even from the NW as the GFS FI shows.

Still as the most experience members know, the pattern can break down before we know it and thats the only straw I can clutch at the moment.

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Posted
  • Location: Bearsden, East Dunbartonshire
  • Location: Bearsden, East Dunbartonshire

A green christmas and new year are more or less guaranteed now with a tropical maritime flow covering at least the south of the uk, again there is a chance of the high to the south building into southern areas and bringing the twin hazards of fog and frost but if the flow remains moderate or fresh from a predominantly sw'ly quarter, it will remain either mild or very mild over christmas with temps of 12-14c possible, probably a bit cooler in the north with a flow from the north atlantic keeping temps nearer to 8-10c for most of the time but the northern third of the uk probably remaining generally unsettled with spells of rain and stronger winds with a few brighter, colder and showery interludes.

Not exactly guranteed yet. What I'm hoping for is the timing of events to change. A predicted cold snap on the 23rd to either last longer; be more potent; start at a later date - the cold snap on Boxing Day to start earlier.

I really am praying that we'll still be under relatively cool uppers come Xmas Eve and I would love it if we have some remaining lying snow on the ground come midnight 25th December.

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