Model Output Discussion - The Start Of Winter

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

well looking  deep into f1 it might  be  cold  but still cant see  any snow yet plenty of rain by wednesday we should know what to expect on the  big day!!  i hope  i am  rong

[Polar Maritime]

So it's looking like the cool/cold N/Wly theme is to continue for some time yet. With sharper colder more unsettled Pm shots as the Month progresses, And maybe turning more Northerly at times. An interesting period of model watching coming up over the next week or so as they firm up on detail for the up-coming festive period. 

Edited December 6, 2014 by Polar Maritime

[Summer Sun]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

well looking  deep into f1 it might  be  cold  but still cant see  any snow yet plenty of rain by wednesday we should know what to expect on the  big day!!  i hope  i am  rong

 

Sticking to the reliable plenty of snow for western Scotland and probably higher ground in northern England and Wales at times

 

 

Some snow in the south later next week?

 

 

All in all plenty of snow to come for those 200m and above in the north and IF ECM is onto something then lowers levels in the UK next weekend

[knocker]

The GEM ens isn't making much of the eastern seaboard  low so that. still to be resolved. Very striking temp anomalies North America and eastern Europe.

Charts courtesy weatherbell

 

[Methuselah]

I must agree with you guys: the future is so bright we'll all need to wear shades?

[bluearmy]

nick has covered the ground i was going to post re extended ecm.  what i would add is that the flattening of the pattern shows in the mean for around three or four days (T232 +) before another anomoly drops in (as per next weekend). what we have seen over this past week or so is that the modelled less cold/average spells are being shortened at both ends. the troughing is being extended via amplification and the onset of the flatter pattern is being delayed by more marked ridging ahead of the warm sector.

 

the control is a good example of this as it broadly follows the op but then fails to bring the warm sector through as the fronts occlude against cold euro trough and the depression to our north fails to push ne as the ridge thrown ahead of it makes contact with the russian way to our ne. it appears to get the occlusion to our east but the warm sector slides se having barely got into the uk at all.  we then see a cold trough over nw europe with secondary depressions running into it. finally the main centre near scotland slides se. a cold run for nw europe.

 

will the pendulum swing back again in the morning suites??   

[Summer Sun]

Some big upgrades on the snow accumulation map for the south tonight over the next 3 to  6 days

 

 

Plenty of snow in western Scotland which will be a welcome boost for the ski resorts ahead of the Christmas holidays

 

 

[gottolovethisweather]

For me, the striking aspect is frequency of 'dartboard' lows to N (or even over) UK dominating the 12z clusters out to T+360. A very unsettled look indeed.

 

Blizzards.

Edited December 6, 2014 by gottolovethisweather

[bluearmy]

Blizzards.

 

the 00z ecm london suite didnt seem to show too much re cold runs beyond day 10, nor windy runs, nor particularly wet runs.  the 12z will be worth looking at and if it is markedly different in nuance, one has to ask, anomoly or trendsetter ???

[lorenzo]

Eyes down for the 18z, where the ECM proved an outlier, it did sniff a cold blas 48 hrs ago, as with modelling the drops and pick ups , ebb/flow is typical of pattern switching.

 

18z is the best in class from GFS vis a vis verification, eclipsing the 12z which in itself is a story, until that and having the P up and running again next week. The northerly is not without strat support given the PV movement, wonder what extremes the pub run will deliver..

[Polar Maritime]

Blizzards.

 

Exactly my thoughts there gltw, All the ingredients are certainly there as we move into the Month.

[Daniel*]

Some big upgrades on the snow accumulation map for the south tonight over the next 3 to  6 days

 

 

Plenty of snow in western Scotland which will be a welcome boost for the ski resorts ahead of the Christmas holidays

Quite a large swathe in green including my patch, even if it doesn't settle just to see white flakes dancing through the winter air is good enough. It is good to see the models are firming up on this if anything we are getting upgrades instead of downgrades. Still the future is uncertain...

[gottolovethisweather]

I haven't paid much attention to the models today but good to the hear from many a post in here, that during the more immediate reliable timeframes, things are still looking wintry and going to plan as per my posting from yesterday. 

 

https://forum.netweather.tv/topic/81934-model-output-discussion-the-start-of-winter/?p=3081507

 

• Late Sunday and during Monday, there will be wintry showers for a fair few of us, more especially for those located in exposure to the bitter NW'rly winds and with elevation on their side.
•  
• The track of Wednesday's low remains uncertain still but sure looks another windy period with rain and some snow over high ground.
•  
• Come Thursday and Friday, still feeling very cold in the brisk winds and the snow risk spreads towards Northeastern parts.
•  
• Then we have next weekend's shenanigans with regard to further wintry potential.

 

 

All in all, this is currently happening without an SSW  , without a Scandi high  , without a snow-covered continent   and off a Maritime source, you almost couldn't make it up and still there is wintry weather in abundance.   Things are but yet in the future, so the surface synoptics could easily change daily but not drastically so and one should be patient if looking for snow to fall on your own rooftop. Forget deep prolonged cold and enjoy what we've been given for now coldies is my advice. 

 

Do keep track of the daily fax updates on the attached link, as these will make for fascinating watching over the coming days, with the 528DAM line being key for snow-chasing possibilities in your patch.

 

http://www.weathercharts.org/ukmomslp.htm

Edited December 6, 2014 by gottolovethisweather

[Met4Cast]

18z at T132 is a little more amplified across the Eastern seaboard compared with the 12z, perhaps a slightly longer Northerly on this run 

[Ice Day]

18z is the best in class from GFS vis a vis verification, eclipsing the 12z which in itself is a story, until that and having the P up and running again next week. The northerly is not without strat support given the PV movement, wonder what extremes the pub run will deliver..

 

Now that is a story!!!   Who'd have thought the pub run trumps the rest???

 

Anyway, back to the models, 144 is reeking of potential!

 

 

 

Edited December 6, 2014 by Ice Day

[Jason T]

Wednesday Onwards 528 dam is pretty much covering UK and Ire, All bar the far South until Friday.

 

Edited December 6, 2014 by Jason T

[Polar Maritime]

A few posts have been moved, Please stick to Model discussion only in here. There are other threads for meto outlook.

 

Thanks, PM.

[Geordiesnow]

Detail on any potential northerly is subject to change but the trend does seem to be some decent amplification but that low/shortwave that crosses Hudson into Greenland looks like could be hampering the chances of properly sending any ridge towards Greenland. Its this I'm more interested than the details of any Northerly blast at the moment because this will vary from run to run. 

[shaky]

Wonder whether ian has got any more information regarding the potential snowfall for next Friday and Saturday across central england!! The last 3 gfs runs and also the ecm run a feature across central areas which could provide a bit of interest snowfall wise!!

[bryan629]

There have been a couple of posts this evening that have confused me , Nick L replied to SM`s post about what the ECM showed after t+240  and Nick replied there was decent support for a scandi high between 288 and 360 hrs, ( which is understandable as SM is like most of us on here, anticipating a much colder turn mid month.. ie 288= 18th dec to 360= 2nd jan) in turn invariably supports a much hypotheised forecast to high level building somewhere either to the north east or northwest of the UK.  

 

Then, Ian F  replied to NIck L post that all he could see from the ECM clusters were `dartboard` lows in our vacinity for that timescale. 

 

 

Assuming the ECM 12z wasn`t an outlier heres what the ensembles show 

 

T+144

 

Deep low pressure ` dartboard type` as agreed on all models over or near the UK, a sausage shaped high anomaly stretching way across the atlantic and the USA to the south, and a very flabby high pressure to the east sat over western Russia. 

 

Now lets see what is happening at T+192

 

Hights across the atlantic begin to weaken and at the same time the deep trough over the UK begins to weaken too.. the flabby heights to the east over russia begin to inflate and literally doubles in size. 

 

So at T+240 we have ....

 

A weak azores high penned in well to our south , a shallow looking trough to the north of the uk, which has actually been pushed back by a very good looking high to our east which looks like its advancing westwards. 

 

Sorry Ian, but are you sure you are looking at this years charts and not last years 

 

`IF` the ensembles are any where near the mark we can anticipate stalling lows, trough disruption and if really lucky undercutters.   

Either way, PM flows for the time being, with a chance of heights pushing into Scandi ... fingers crossed!! 

 

 

 

[bluearmy]

Gfs 18z gets some way to the ECM solution re the trough next weekend. Only 8 hours till the next set will pretty well all be out!

[Ice Day]

Uppers at 180 much better for coldies.  The 0c line has moved about 250 miles west, which is nice!

 

1. 

[bluearmy]

There have been a couple of posts this evening that have confused me , Nick L replied to SM`s post about what the ECM showed after t+240  and Nick replied there was decent support for a scandi high between 288 and 360 hrs, ( which is understandable as SM is like most of us on here, anticipating a much colder turn mid month.. ie 288= 18th dec to 360= 2nd jan) in turn invariably supports a much hypotheised forecast to high level building somewhere either to the north east or northwest of the UK.  

 

Then, Ian F  replied to NIck L post that all he could see from the ECM clusters were `dartboard` lows in our vacinity for that timescale. 

 

 

Assuming the ECM 12z wasn`t an outlier heres what the ensembles show 

 

T+144

EDH101-144.gif

 

Deep low pressure ` dartboard type` as agreed on all models over or near the UK, a sausage shaped high anomaly stretching way across the atlantic and the USA to the south, and a very flabby high pressure to the east sat over western Russia. 

 

Now lets see what is happening at T+192

EDH101-192.gif

 

Hights across the atlantic begin to weaken and at the same time the deep trough over the UK begins to weaken too.. the flabby heights to the east over russia begin to inflate and literally doubles in size. 

 

So at T+240 we have ....

EDH101-240.gif

 

A weak azores high penned in well to our south , a shallow looking trough to the north of the uk, which has actually been pushed back by a very good looking high to our east which looks like its advancing westwards. 

 

Sorry Ian, but are you sure you are looking at this years charts and not last years 

 

`IF` the ensembles are any where near the mark we can anticipate stalling lows, trough disruption and if really lucky undercutters.   

Either way, PM flows for the time being, with a chance of heights pushing into Scandi ... fingers crossed!!

Nick and ian are referring to the ECM clusters. The anomolys won't necessarily pick that up and the mean post day 10 definitely won't.

Your best indicator that we can see will be the london graphs in 30 mins

[BLAST FROM THE PAST]

Nick L, BA and Big Steve have touched on it re potentially looking NE as we go down the line?  More upgrades to come re longevity imo and potential severity of this developing cold spell.

So as 18z rolls out, similar theme for next week.....pM air and 'BELOW' average generally....we'll see what happens as we go along...but below average to well below average is still my view. 

ECM towards end of run interests me, I think a period to also watch......easterly anyone?  I'm very happy with the Atlantic ridge and amplification and northerly to start...now I anticipate a flow from N to E quadrant to dominate...so I anticipate the block to hold/even strengthen and for the trough to move south into Europe down the line.  A very good start...

 

BFTP

Edited December 6, 2014 by BLAST FROM THE PAST
To remove remarks to meto.

[Nick L]

Nick L, BA and Big Steve have touched on it re potentially looking NE as we go down the line?  More upgrades to come re longevity imo and potential severity of this developing cold spell.  I think BB was right that MetO may well be 'adjusting' their average to above outlook....

So as 18z rolls out, similar theme for next week.....pM air and 'BELOW' average generally....we'll see what happens as we go along...but below average to well below average is still my view. 

ECM towards end of run interests me, I think a period to also watch......easterly anyone?

 

BFTP

 

Around 10% of the ensemble members go for a lowering of heights over Europe, and HP taking hold to our NE. But 20% go for a Euro high!

 

The predominant pattern is one from the west or northwest, continuing the average-to-cold conditions, while remaining unsettled. The snow over the Scottish mountains could well continue to pile up.