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Model Output Discussion - The Run In To Christmas


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Unfortunately, there needs to be a recognition that if we share at *this tentative juncture* the exact nature of what we have as Ops Centre guidance, certain individuals will inevitably extrapolate/wa

If the UK can't get cold from an upstream pattern with a negatively tilted troughing setting up over the ne USA , indeed the best set up since two winters ago then I will seriously consider throwing m

The good news just keeps on coming!   Upstream pattern is falling into place to deliver what many people in this thread want to see, NCEP give us the best update since winter 2012/2013,  indeed I'm

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Come on guys, what would model watching be without massive swings in output?

When've we ever had the lead up to a cold period which is smooth the whole way through, with no potential issues in output?

Don't lose the faith anyone (most of you havent anyway), it it wasn't for such happenings, we wouldn't have a country with so many enthusiasts - you'd look at the models once and not need to look at them again for a few days!

I think it's just the models struggling with detail personally - the trends are still there, so hopefully they continue :)

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Paul Bartlett was a former forecaster for the Met Office , the term ' Bartlett High' was linked to Paul.......not sure exactly how , I am sure some on here could tell you.

 

Surprised you haven't heard of him??

 

Paul passed away nearly 3 years ago

I didn't know Paul had died, very sad.

The term Bartlett High first appeared in the very mild winter of 1998 when Paul described a series of high pressure cells moving across the Atlantic and settling over Southern Europe creating very mild conditions in the UK and the exceptionally mild weather of mid February 1998.

A true Bartlett has been a rare thing since 2005 but was a source of great pain for many NW and TWO model watchers between 1998 and 2005.

Andy

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GFS ensembles are wobbling around and with the ensemble suits overall out of kilter with the operational and indeed control runs in the latter stages there is both room to be optimistic and/or pessimistic (the and is for those who enjoy ambivalence) 

 

 
ECM control pretty much a mild outlier and Op mildest of entire suite day 9/10. Extraordinary.

 

ensemble-tt6-london.gif

 

 

GFS ensembles paint a similar picture.

 

graphe3_1000_288_114___.gif

 

 

 

Expect much flipping and flopping to come (and that is just the forum members)

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Right let me get my head around this after reading through pages and pages, the ensembles and mean are very good on the ecm and the op is not bad but is what is considered an outlier in relation to its other members. And the gfs gives us a taste of deja vu with again good gefs and mean but a shocking op. What is more important is it the op or the mean as I am completely confused.

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Re: Bartlett High - what is less well known is that Paul himself was actually a coldie who despised mild mush. Although his name became associated with 'Uncle Barty' thanks to a forecast he made during the very mild winter of 1988, he never welcomed his namesake's arrival!

R.I.P Paul

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Well not long to wait  before the 0z runs comes out, one thing is for sure we need a swing towards a colder run from the Gfs, because despite what people think, it is one of the worlds top Computer models, at that range 144, a week or so later any weather computer model is prone to chop and change, This  is what Meteo France are saying anyway for the new year period( who in my opinion are a very professional metrological organisation, as Ian Fergusson as stated here before.) their opinion is that, there is a 70% chance of a normal cold spell, the type of cold spell that gives temperatures of 2 or 3, 4 degrees with snows showers .This could continue at least until the first week of January or beyond.Then there is a 30% chance that things could turn milder from the Atlantic around the new year itself. They also go on to say that there is a 10% chance of the weather around new year, turning into a severe cold spell.  I personally think given the uncertainties , this is a very good forecast of the probabilities. Whatever the results of the 0z,  don't get stress out, remember it is only the weather, we are still in December, there is still more time for cold weather outbreaks, enjoy the festive period and relax.   Gender Male. Location Battersea London.

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Yes Azores high playing spoiler, we just can't get the trough to push far enough South so GFS and GFS(p) have pretty much given up the ghost though the parallel at least tries to keep things interesting into deep FI.

UKMO may show some hope.

 

UN144-21.GIF?19-05

 

Perhaps we can have a shortwave saviour from the Northwest before we get the spoiler from the SW?

We need a deep trough to amplify the pattern behind and to prevent high pressure toppling over the UK - if that shortwave/low developed enough it could do the trick though any cold would be delayed - better than no cold at all though.

 

GEM doesn't offer Xmas cold but at least still has promise at day 10. (hopefully it won't be one of those winters where we are forever chasing FI cold. I think we would be very unlucky if that were case and believe patience will be rewarded eventually)

 

ECM could change the mood if the Op is good and the ensembles hold steady.

Edited by Mucka
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Day 6 charts

UKMO

UN144-21.GIF?19-05

The northerly might get there on the second attempt

GFS

gfsnh-0-144.png?0

GFS (P)

gfsnh-0-144.png?0

GEM

gemnh-0-144.png?00

The majority of the operationals are really cutting out the potency of the northerly around Christmas day, looking like the cold front clears to a dry and fine Christmas with overnight frosts, that said there could be issues in the south as the cold front struggles to clear the south coast, meaning a cloudy and damp day there (temperatures 4-8C across the board). Not bad but obviously a disappointment compared to the charts we saw. The ECM will be interesting viewing.

At the present time it looks like the low to our south west was well and truly underplayed in the previous outputs.

Edited by Captain shortwave
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Dont think theres anything wrong with this mornings output so far!! For me its not the azores low that scuppers the chances!!its the damn shortwave coming down from the north west that does it!! We were worried about the one to the south west but that keeps getting pushed back west with every run!!

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Wave 1 of the cold air doesn't really take off, in fact the south gets another day of double figure maxima (Christmas Eve).

But still a chance with wave 2 which starts it's descent from Boxing day

ECH1-168.GIF?19-12

Where does it go? If it goes south east then we go cold as the Azores ridge builds north west, if it phases with that Atlantic low then it's south westerlies again.

The models at least agree on a mostly fine Christmas and Boxing day with night time frosts likely. Again the caveat being issues with the cold front pushing south before that time and its potential to stall.

Day 8

ECH1-192.GIF?19-12

looks ok.

Edited by Captain shortwave
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I think i will put a bigger lock on the knife cupboard this morning to save people, following GFS s every run, trying to commit hari kari.

 

ECM better with an interesting little feature,even if it will have gone by 12z

http://www.meteociel.fr/modeles/ecmwf/runs/2014121900/ECH1-144.GIF?19-12

http://www.meteociel.fr/modeles/ecmwf/runs/2014121900/ECM0-168.GIF?19-12  dont let the z500 chart deceive you

http://www.meteociel.fr/modeles/ecmwf/runs/2014121900/ECH1-168.GIF?19-12

Cold air in situ and wave 2 incoming  

http://www.meteociel.fr/modeles/ecmwf/runs/2014121900/ECH1-192.GIF?19-12

Edited by winterof79
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This is a model run we all feared not looking good azores high all over the uk and no block in place i fear this is the final nail in the coffin for xmas day

Judging by the downward trend for cold, I would say not just for Xmas day but the general holiday period.

All of those so called knee jerk reactions in response to yesterday's 12z suites are looking more and more justifiable..unfortunately!

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Judging by the downward trend for cold, I would say not just for Xmas day but the general holiday period.

All of those so called knee jerk reactions in response to yesterday's 12z suites are looking more and more justifiable..unfortunately!

If you take the GFS as gospel of course. :rolleyes:

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014121900/ECH1-216.GIF?19-12

Edited by winterof79
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Yes Azores high playing spoiler, we just can't get the trough to push far enough South so GFS and GFS(p) have pretty much given up the ghost though the parallel at least tries to keep things interesting into deep FI.

UKMO may show some hope.

 

UN144-21.GIF?19-05

 

Perhaps we can have a shortwave saviour from the Northwest before we get the spoiler from the SW?

We need a deep trough to amplify the pattern behind and to prevent high pressure toppling over the UK - if that shortwave/low developed enough it could do the trick though any cold would be delayed - better than no cold at all though.

 

GEM doesn't offer Xmas cold but at least still has promise at day 10. (hopefully it won't be one of those winters where we are forever chasing FI cold. I think we would be very unlucky if that were case and believe patience will be rewarded eventually)

 

ECM could change the mood if the Op is good and the ensembles hold steady.

 

 

And as if by magic...

 

Very good agreement between UKMO and ECM 144 with ECM having things a little further West but we can see how that shortwave I mentioned to the NW is there and how its develops and pushes SW reinvigorating the trough.

 

ECH1-144.GIF?19-12UN144-21.GIF

 

And by 192 on ECM.

 

ECH1-192.GIF?19-12

 

I think this may be are only hope of a quick route to cold but relying on track and development of a shortwave modeled 6 days out is somewhat tenuous - albeit UKMO and ECM are in pretty good agreement on it.

 

If the output goes along these lines there could well be a big snow event somewhere in England before December is out.

 

ECH1-216.GIF?19-12

Edited by Mucka
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Didnt think the ecm would look that good in the end but it manages to push that low south eastwards! ! Pretty good start to the day!! Think gfs is struggling at the moment with this pattern! ! Ukmo looks pretty good as well! !

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From my time watching the charts once they flip this close to T0 then it is unlikely they will flip back. However the spread is so high that making any conclusions just yet would be rash:

 

post-14819-0-93882000-1418970080_thumb.p  The mean offers hope: post-14819-0-33055700-1418970366_thumb.p

However the hi-res led the ensembles towards the Atlantic ridge and it took several runs before they came on board. It could be the case in such an uncertain synoptic that the ensembles will only gradually flip back to the op. Until we know D8 the rest of FI is rather mute.

 

GEM is still amplified but the cold has shifted east so very little of wintry interest up to D10: post-14819-0-43190300-1418970378_thumb.p

 

I am not sure UKMO is going anywhere, certainly a downgrade at D6: post-14819-0-30129500-1418970525_thumb.g

 

There are cool uppers but it is a rather underwhelming. Looking at the ECM, if you strip it down ignoring the "potential" all you have is the same pattern, a brief N/Nw'ly (d6), a ridge (d7), followed by a LP (d8). D9-10 is usually outlier territory so can be arguably ignored.

 

Just ordinary December fare whilst we await the early Jan strat effects.

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ECM T192/T216 - fascinating picture with an Arctic blast on the verge of reaching us, but still too soon to call.

I'm looking at that little low in the Atlantic around T144. If it cuts off, heights build NW around it rather than NE and the block to its north is better established. UKMO is best, with a complete cutoff, ECM partially cuts off and GFS doesn't cut it off much at all.

Problem is, the phasing of these cut off lows sometimes doesn't get resolved until T72!! Merry Christmas everyone then...

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