Model Output Discussion - The Start Of Winter

[Cloud 10]

Hi Nick - I can understand why using De Bilt as a meteogram / EPSGram site might have relevance to UK for assessing an incipient easterly/continental boundary layer-coming-to-us set-up, but not convinced it's best representative in broader sense...nevertheless it seems to be cited regularly on this forum, but I've never understood why? Cheers.

 

I think its more to do with the fact that its one of the very few longer range ECM products which can be seen 

by everyone,so is tended to be used in winter quite a lot!

 

 

LOL,i think that's cleared that up then.

Edited December 7, 2014 by Cloud 10

[fergieweather]

Thanks for replies re De Bilt... I hadn't realised no EC ENS site data for a representative UK site isn't available on public websites somewhere.

[knocker]

The anomalies this morning and tell much the same story although last night's NOAA 6-10 hasn't quite caught up. ( if that's the correct way of putting it of course)

 

The GFS and ECM have the trough orientated SE either over the UK or slightly to the east. HP North America eastwards over the Atlantic and also eastern Europe. Low Pacific and Siberia, NOAA is rather more bold with the UK trough but less so on the 8-14 when it realigns it to accommodate the northward movement of the HP.

 

In a nutshell, as has been said previously, no sign of any significant change with periods of very unsettled weather with about average temps. The detail of this will of course engage minds over the next few days.

 

Charts courtesy weatherbell

 

 

[karyo]

Disappointing morning output across the board. It seemed yesterday that we could squeeze the best out of a bad situation (as there is no northern blocking) but today the models are serving us something much more average and expected given the situation.

 

With the stratosphere getting colder and the mean zonal winds on the up I can't see any significant wintry spell coming up. We have to hope that the anticipated major stratospheric warming happens at the end of the month to give us a promising January so that's what we have to look out for.

 

Karyo

[bluearmy]

Thanks for replies re De Bilt... I hadn't realised no EC ENS site data for a representative UK site isn't available on public websites somewhere.

 

i think it reflects the fact that most cant wait for 11am/pm when meteogroup issue the london ones (though if anyones reading. the addition of wind directions wouldn't go amiss) as these are useful when colder runs begin to show.

 

not much for coldies in the extended - if you are an optimist, you might see the weak low anomoly getting south of the uk back end of week 2 in tandem with a possible height rise to our ne being significant. at T360/T384 being positive.

[carinthian]

Have you ever thought of  becoming one of my  helpline operatives? We're doing a recruitment drive and expect a big increase in demand.

 

We need people that can be positive in the face of adversity! lol Going back to the models in terms of the ECM ensembles.

 

http://www.weerplaza.nl/15daagseverwachting/?r=midden&type=eps_pluim

 

The main clustering for De Bilt looks pretty average, theres still a few colder solutions which have survived this mornings carnage, overall though its looking uninspiring from a cold perspective after this weeks brief flirtation. A week can be a long time in the NWP and lets hope something more interesting shows up towards the Christmas period, I hope we can avoid a mild mush festive period.

Love reading your posts and your highs and lows. Nick I would be no good on your help line. Mild weather makes me miserable and I decay like compost . Its mainly for that reason that I reside at 1650 m als constrained into the obedience to hide away from maritime influences of the wrong type. As you report a week can be a long time in the NWP. Anyway going for a walk in the snow that's now settling , deep crisp and even. Wish all you snow lovers were here with me and head to the pub for a Sunday pint!

C

[shaky]

Once again the models particularly ecm backtrack! ! Wasn't expecting it to look that bad this morning but it is!!! Maybe the uk seasonal meto model might be onto something here and we gona have a bog standard winter!!! We seriously gota hope that the warming happens back end of December/january otherwise it could be time to get the violins out! !!

[fergieweather]

Once again the models particularly ecm backtrack! ! Wasn't expecting it to look that bad this morning but it is!!! Maybe the uk seasonal meto model might be onto something here and we gona have a bog standard winter!!! We seriously gota hope that the warming happens back end of December/january otherwise it could be time to get the violins out! !!

Shaky: Whilst GloSea5 signals for December prospects have exhibited fair confidence, it remains the case that greater uncertainty then emerges further into winter (as UKMO have been at pains to stress) due to a less definitive NAO signal; easterly QBO plus *possible* SSW. However, whilst often doing so historically, the latter *does not* singularly assure a deep cold pattern for UK (in case some believe it does!). Many (some competing) drivers are at play and I would urge against knee-jerk 'write-off' of entire winter based on current NWP across 1-15 days...!

[Matty M]

Cheeky shows up on the 6z GFS, so coming more into line with the UKM/EC solutions.

 

These type of systems have the potential to give some severe winds.

 

Developing as it exits east coast on this run.

 

[Penrith Snow]

Great words of advice from Fergie.

I have learnt over the years to take the models at +144 and beyond with a pinch of salt as they swing widely and in my experience if the MetO haven't picked up on a cold spell in their MRF one isn't coming despite a few Stella ECM runs.

At the moment all the signals are wrong for sustained cold and this cool zonality will be with us for sometime, ignore the big swings in the models from one run to the next like the 12z and 00z and concentrate on trends then the fax charts. Oh and I expect the 12z not to be as bad as the 00z as the pendulum continues to swings back and forth.

The situation could still be worse and the long fetch northerly on the charts last night might happen eventually not just yet.

Andy

[blizzard81]

The ECM ops have been quite volatile these last couple of weeks in particular. They seem to offer up the extreme solutions. I notice last nights run was a marked cold outlier for debilt and this morning's run is just about the warmest run at days 7 & 8. Lets see what the 12z run shows. I remember yesterday morning's run wasn't so cracking for cold so there maybe more uncertainty than people realise.

[ANYWEATHER]

Morning folks. Been away for a week on a busmans holiday so had no time to post etc. Looks like the cold has stepped up a pace in the last week with the gfs and ecm showing frequent shots of Polar Maritime air across the nation in the week ahead. It looks as though the north of the uk will get plenty of wintry precip especially given elevation, southern areas of the uk cold and wet at times rather than wintry, although upland areas of England IE, such as the Cotswolds and Malverns may see some brief snow falling  at times ,but lowland snow looks unlikely in southern parts of the uk, although not out of the question given the synoptics. Anyway, the old saying, the devil will be in the detail will certainy be true this coming week, but all in all a great seasonal start to Winter.

[IDO]

ECM snow accumulations for the next 7 days suggests Highlands and hills of the north the main concern: 

 

  MarkVogan
ECMWF buries Highland Scotland within the next 7 days alone! Could see covering to low levels following Wed storm. http://t.co/4NRARBc6uL
07/12/2014 10:28

 

Nothing further south.

 

The GFS 06z continues with the theme for next weekend of a ridge building in from the SW so mostly dry with a slack upper cold flow (>-4c) with any snow mainly showers in coastal regions:

 

 

So cold in the north and cool in the south. From D8-10 we have a SW'ly flow dragging in warmer uppers and that probably explains why the ECM op is in the warmer regions for DeBilt, it has latched on to this TM flow (GEM picked this up a couple of days ago and GFS joined in, ECM now catching on):

 

 

Same old same old from D10 for the consistent GFS out till D16: 

 

Warming remains at 10hPa: 

 

 

[blizzard81]

Gibby's analysis again broadly fitting UKMO overnight assessment. Noting caveat of 'significant uncertainties' even at the start of the 6-15d period & reflecting (as per my post last night) EC-ENS clusters, the Deputy Chief Forecaster concludes: "... uncertainties are likely to continue into the longer range, but anomalies of pressure and gph around the UK imply stronger than usual winds through the atmosphere and potentially stormy conditions continuing in the broadly W’ly flow." Colder phases with temps expected panning-out as average or slightly above.

Hi Ian and many thanks for the continued updates. May I ask what the uncertainties are in relation to ? This seems like a departure from last night's update which seemed to indicate a high degree of confidence.

[stewfox]

 I think the likes of Tamara have some explaining to do as to why this ded cert pattern change is looking unlikely to happen.

 

Sorry mods if you want to put this in another thread but I think its disrespectful.

 

I am not aware Tamara gets paid a heavy fee for the time and effort she puts in ? if you can highlight the 'ded cert' she mentions please provide a link.

 

Its also been pointed our that changes in NH patterns doesn't always lead to snow IMBY on a specific date 

 

If this was a exact science we wouldn't need this thread and ps its still FI

[winterof79]

Hi Ian and many thanks for the continued updates. May I ask what the uncertainties are in relation to ? This seems like a departure from last night's update which seemed to indicate a high degree of confidence.

My understanding of Ian's updates has been UKMO has high confidence in 6-15d period that temps will be average/slightly above and unsettled and often very windy.Thereafter uncertainty is much greater.Regards.

Edited December 7, 2014 by winterof79

[karyo]

The MJO seems to be making it to phase 6 now but still expected to die before entering 7. 

We could so do with a push here!

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

Karyo

[blizzard81]

My understanding of Ian's updates has been UKMO has high confidence in 6-15d period that temps will be average/slightly above and unsettled and often very windy.Thereafter uncertainty is much greater.Regards.

His post states significant uncertainties even at the start of day 6 - 15 period ?

[IDO]

His post states significant uncertainties even at the start of day 6 - 15 period ?

 

 

I suspect it is more to do with surface conditions rather than the long wave pattern. eg. will incoming depressions deepen; so how windy? The TM incursions: how far NE will they push and how transient are they? How cool will the uppers be? etc.

 

Looking at the NH profile; absolutely no signal for HLB in the next two weeks, so a zonal/westerly pattern with cold on the back edge of passing cyclones, giving average temps to the south and below to the north.

 

Well thats how I see it.

 

06z for London:

 

You can see where the highest uncertainty is using the spread:  

 

The UK has the greatest uncertainty but little spread elsewhere; a sure sign the pattern is pretty set, just the finer detail as to surface conditions.

Edited December 7, 2014 by i'm dreaming of...

[blizzard81]

I suspect it is more to do with surface conditions rather than the long wave pattern. eg. will incoming depressions deepen; so how windy? The TM incursions: how far NE will they push and how transient are they? How cool will the uppers be? etc.

 

Looking at the NH profile; absolutely no signal for HLB in the next two weeks, so a zonal/westerly pattern with cold on the back edge of passing cyclones, giving average temps to the south and below to the north.

 

Well thats how I see it.

 

06z for London: graphe6_1000_306_141___Londres ( .gif

 

You can see where the highest uncertainty is using the spread:  gens-22-1-240.png

 

The UK has the greatest uncertainty but little spread elsewhere; a sure sign the pattern is pretty set, just the finer detail as to surface conditions.

Yes, you are probably right. I suppose most people are now turning their attention to xmas week which, imo is still up for grabs. I think much will depend on whether or not the pv moves from the Greenland vicinity. I notice that GFS means still point to this post 10 days and moving the core to the other side of the pole. This will be crucial for cold prospects during Christmas week.

[Duane S.]

I would agree with IDO, localised uncertainties leading to just how stormy and how much of an element of Northerly will be mixed in the predominantly westerly driven weather (and later, how much, if any, TM air mass makes it in). Longwave pattern not likely to be affected by any significant amplification for a while yet so expect to see the Azores turn from friend to foe in here fast as it makes weak attempts to ridge north and gets continually flattened. My thoughts haven't changed from 10 days ago, I think we need to look east for where the ridging is going to head, eventually! But in the meantime of course we have anything but boring weather to keep us occupied...

[IDO]

Yes, you are probably right. I suppose most people are now turning their attention to xmas week which, imo is still up for grabs. I think much will depend on whether or not the pv moves from the Greenland vicinity. I notice that GFS means still point to this post 10 days and moving the core to the other side of the pole. This will be crucial for cold prospects during Christmas week.

 

All things will change in the next 7-10 days in the GFS FI IMO. The current pattern will have no legs with the way the PV is; so changes for the last week of December into the first week of January. What comes after when the pattern changes is the interesting conundrum. At the moment the far reaches of FI suggests it's the US that will get another Arctic plunge:

 

Control  op: 

[blizzard81]

I would agree with IDO, localised uncertainties leading to just how stormy and how much of an element of Northerly will be mixed in the predominantly westerly driven weather (and later, how much, if any, TM air mass makes it in). Longwave pattern not likely to be affected by any significant amplification for a while yet so expect to see the Azores turn from friend to foe in here fast as it makes weak attempts to ridge north and gets continually flattened. My thoughts haven't changed from 10 days ago, I think we need to look east for where the ridging is going to head, eventually! But in the meantime of course we have anything but boring weather to keep us occupied...

Yes, further to my post earlier, I have looked through the 06 gfs ensembles and while the pv over Greenland loses it's intensity, there is still a signal for an annoying lobe to sit there in 2 weeks time. The good thing though is that it is situated in north west Greenland which might just give us enough wriggle room for some form of easterly as the block to the east shows no sign of waning.

[Nouska]

My understanding of Ian's updates has been UKMO has high confidence in 6-15d period that temps will be average/slightly above and unsettled and often very windy.Thereafter uncertainty is much greater.Regards.

 

A wee, sneaky peek at the Reading EPSgram shows this up well - big spread after Saturday, the control and deterministic are at the top of the range at the end of forecast period.

 

http://i.imgur.com/55jJzgi.gif

[bluearmy]

A wee, sneaky peek at the Reading EPSgram shows this up well - big spread after Saturday, the control and deterministic are at the top of the range at the end of forecast period.

 

http://i.imgur.com/55jJzgi.gif

http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london

And in the extended, plenty of clusters over a wide spread.