Model output discussion - 1st December onwards

[Cheshire Freeze]

Interestingly, gfs control gives us a fully fledged Scandi high and associated cold pool towards day 10. The amplification we're seeing modelled seems to be gaining ground quite quickly now.

[SMU]

Morning -

Day 10 ECM is probably the most significant chart of the winter so far - Seeing a large cold pool cut off over Eastern Europe 

If the UK is going to get anything significant from this developing High then at least the ECM gives us a chance -

based on the day 10 you would be looking day 12-14...

 

so a LONG way away at the moment - but at least a chance.....

S

Edited December 20, 2015 by THE CHOSEN ONE

[Polar Maritime]

The GFS shows much cooler seasonal weather over the UK by the turn of the year, With a cool/cold N/Wly flow turning Northerly as the Jet slowly sinks South. Expect more wild swings reg height rises into the the extended period, As the models continue to toy with background signals over the coming days so. Promising signs as we head into January continue this morning.

Edited December 20, 2015 by Polar Maritime

[IDO]

What is remarkable is that as of the 18th the CET is +4.9c over average for December and looking at the ECM this morning we could see the last five days of temps maintain this anomaly:

Anyway the wave trend continues to favour a ridge to HL in the GEFS with only 33% now saying "No". The rest are on board in one way or other.  Looking at those, they vary from a Scandi upper high to a Sceuro ridge. By T300 there is still about 33% (half those that show a HLB) keeping some sort of block in place. Just for fun as we have not even nailed how this initial amplification will manifest yet, so longevity is mute from the current data.

The CFS week 2 anomaly is very ECM like with a southern flow into the UK bringing very mild uppers. Whilst w3 shows more of a Continental flow so I would expect a cooling down to closer to seasonal temps:

Week 1&2    Week 3&4

Still confidence in the week 2 pattern is not strong as i suspect ECM OP is showing close to the best case scenario whilst the GFS Op is edging slowly away from the worst case outcome from this likely setup. Usually somewhere in the middle is the best bet till it is resolved. For instance the GEM were bullish of a tasty Scandi anomaly yesterday, but the oz is now just showing a small packet of weak heights move through that region during D9 and D10:

D10 GEM:    UKMO    ECM 

UKMO are also less keen as early as D6 for the ECM scenario^^^.

See what the 12z runs come up with...

 

 

[bluearmy]

tending to agree with IDO that this upcoming amplification morphing into sceuro ridge will not be sustained. Looks to be too much mobility in the pattern upstream. of course, there will be some effective wave activity shoved high up from the ridge but it won't be long lasting, judging by the current output. tell tale chart of the day is the day 10 ECM spread.  However, there is mileage in a ridge being sustained further ene. Maybe we could call it a scrussian ridge? 

slowly, slowly .   Nothing to write off.  In respect of the monster strat p/v, 'the bigger they are'

Edited December 20, 2015 by bluearmy

[BLAST FROM THE PAST]

But the Sceuro could develop and hold, sitting n the wrong place for cold and we get a constant S to  W flow through Jan.....I think that set up is pretty easy for this country to hold for a long time as depressions will generally 'happily' take that route of SW/NE.  That brings a familiar ring to it.  This December seems to be writing on the wall as regards to where we may sit 'generally'.  One thing though is that 'seasonal' weather is possible with slight shifts bringing fog and frost or LPs tracking a little further south but the safe bet is for 'generally' more mild longer term.   This stretch is pretty extreme, not unheard of by any stretch of the imagination but extreme nonetheless. 

Nearer time, Yet Another LP from SW coming in to cut off any cooler/cold feed.....exhausting

 

BFTP

Edited December 20, 2015 by BLAST FROM THE PAST

[blizzard81]

10 minutes ago, Greenland1080 said:

Tantalisingly close to a colder snowy fest only our tiny island can stay on the mild side

 

Yes, isn't it amazing just how many times the UK gets stuck in that narrow mild wedge? Lol

[mountain shadow]

The only good thing about the 6z GFS is that it just about shows a split PV at 30hpa in deepest fi. That remains our only route to cold sometime in January or February.

[Cloud 10]

GFS 06z now picking up on the small Iceland high at day 6 which appeared on yesterday's ECM 12z.

 

yesterday 06z..

 

today 06z..

Edited December 20, 2015 by Cloud 10

[blizzard81]

8 minutes ago, Cloud 10 said:

GFS 06z now picking up on the small Iceland high at day 6 which appeared on yesterday's ECM 12z.

 

yesterday 06z..

 

today 06z..

This is the most noticeable aspect of this mornings runs. To give credit to ECM, it picked this small area of high pressure a few days ago. Momentum seems to be picking up on this feature. It is still 6 days away and the models will struggle as it is an unusual pattern in our neck of the woods. They could still be underestimating the amplification. 

[blizzard81]

Looking at 00z ECM Debilt ensembles, and there are more colder members in the mid to long term when compared to yesterday's 12z set.

[AWD]

5 minutes ago, blizzard81 said:

Looking at 00z ECM Debilt ensembles, and there are more colder members in the mid to long term when compared to yesterday's 12z set.

London ens show a small cluster going chilly around boxing day, no doubt from a ESE continental feed.

Majority seem to show a decline to something around average though, which after the very mild temps of recent days, is one of the easiest things to write on here.

[Frosty.]

There is some good news from the Gfs 6z within the reliable timeframe, much less of a blowtorch, apart from tuesday so at least knocker will have to turn down the AC in his woodshed at times during the week ahead!

[Interitus]

A quick note regarding the stratosphere, those looking for a change may want to look elsewhere for quite a while. The GEOS model forecast up to 27th December shows further strengthening. Assuming it is correct, the figures suggest that a full SSW is, while not impossible, probably unlikely before the last third of January at earliest and could be into February. The earliest SSW from the forecast stratosphere (six levels 10mb - 150mb) 90°N temperatures is about 23 days and for 80°N temperature about 25 days - which would be 21st January at earliest. Indeed for the forecast 90°N 50mb and 80°N 30mb temperatures, I don't think there has been a following SSW in the MERRA data from 1979 to present.

[nick sussex]

Its the same old story this morning with the shortwave phasing game of poker leaving us with two pairs against the full house.

This makes any route to cold so much more difficult so we've gone from climbing Snowdonia to now trying to get up to the summit of Mont Blanc.

Especially frustrating as the upstream pattern has a window of opportunity but this phasing essentially stops the ridging north much earlier, any time you get a trough phasing with a shortwave energy will want to go ne and the troughing gets pulled further east at the same time.

You'll see that the ECM still has low pressure running ene towards the Great Lakes, this will then run into the UK troughing, this motion and phasing of energies will force energy off the trough. If you have the high further north and west you would have a decent chance of energy disrupting off that trough se into southern Europe.

If we accept that we're going to be subjected to more shortwave drama then you don't want the shortwave stuck too far east, if its going to phase you want it as weak as possible and as far west.

You only want this further east if it can separate cleanly from that troughing. You certainly don't want the UKMO solution!

Although there are still some decent colder ECM ensembles with a clustering taking winds round towards the east we need a lot to go right at the initial T144 to 168hrs timeframe and given recent weeks if things can go wrong they do so I'd say today that colder chances have taken yet another knock.

Theres a window of opportunity because the models do want to dig that troughing south to the west but this is likely to close if the models combine to deliver the least favourable phasing outcomes.

[Ruben Amsterdam]

44 minutes ago, blizzard81 said:

Looking at 00z ECM Debilt ensembles, and there are more colder members in the mid to long term when compared to yesterday's 12z set.

This mornings run (note that this is for the eastern part of the Netherlands, close to the German border, De Bilt is in central the Netherlands and is a bit warmer, usually) shows some colder members indeed. Mostly inversion weather in a slow continental flow, would be my guess. I also included an ensemble with wind directions which shows a tendency towards more south/easterly winds instead of south westerly wind, but this is not all convincing yet.

From top to bottom: T2m, dew point, precip., wind 10m, wind 10m gusts, cloud cover.

Edited December 20, 2015 by Ruben Amsterdam

[Frosty.]

20 minutes ago, nick sussex said:

Its the same old story this morning with the shortwave phasing game of poker leaving us with two pairs against the full house.

This makes any route to cold so much more difficult so we've gone from climbing Snowdonia to now trying to get up to the summit of Mont Blanc.

Especially frustrating as the upstream pattern has a window of opportunity but this phasing essentially stops the ridging north much earlier, any time you get a trough phasing with a shortwave energy will want to go ne and the troughing gets pulled further east at the same time.

You'll see that the ECM still has low pressure running ene towards the Great Lakes, this will then run into the UK troughing, this motion and phasing of energies will force energy off the trough. If you have the high further north and west you would have a decent chance of energy disrupting off that trough se into southern Europe.

If we accept that we're going to be subjected to more shortwave drama then you don't want the shortwave stuck too far east, if its going to phase you want it as weak as possible and as far west.

You only want this further east if it can separate cleanly from that troughing. You certainly don't want the UKMO solution!

Although there are still some decent colder ECM ensembles with a clustering taking winds round towards the east we need a lot to go right at the initial T144 to 168hrs timeframe and given recent weeks if things can go wrong they do so I'd say today that colder chances have taken yet another knock.

Theres a window of opportunity because the models do want to dig that troughing south to the west but this is likely to close if the models combine to deliver the least favourable phasing outcomes.

Nick, let's be honest, the models are still an absolute nightmare for coldies in the uk. I recently read a post from Tamara from back in early november and she saw this horror coming. I must say I was excited about an El Nino winter when I remembered the pure joy that 09 / 10 brought for cold fans. however, I remain hopeful that Jan/Feb/March will see a marked change for the better for the majority on here! 

[nick sussex]

4 minutes ago, Frosty. said:

Nick, let's be honest, the models are still an absolute nightmare for coldies in the uk. I recently read a post from Tamara from back in early november and she saw this horror coming. I must say I was excited about an El Nino winter when I remembered the pure joy that 09 / 10 brought for cold fans. however, I remain hopeful that Jan/Feb/March will see a marked change for the better for the majority on here! 

Yes I'm being realistic about prospects, I'll give the high to the east one last chance because theres a window of opportunity in the next ten days because of those changes in the Pacific but we'd need a lot to go right with those shortwave phasing issues. We'll see in the next few days.

[Liam J]

Heights don't build as far north on the EPS control compared to the last few frames of the ECM OP with the high centred further south on the control run, but a similar theme that keeps us in a south or south westerly flow right into the new year with energy going over the top of the Euro or Sceuro high attempt. NYE shows a 1040mb high over SE Europe with SW'ly winds for the UK and on into into Scandinavia, 850's 5-10c, by the 3rd January heights have been pushed further away leaving the UK in a cool PM westerly and sub zero 850's which would make a refreshing change! 

Edited December 20, 2015 by *Sub*Zero*

[nick sussex]

7 minutes ago, *Sub*Zero* said:

Heights don't build as far north on the EPS control compared to the last few frames of the ECM OP with the high centred further south on the control run, but a similar theme that keeps us in a south or south westerly flow right into the new year with energy going over the top of any Euro or Sceuro high attempt. NYE shows a 1040mb high over SE Europe with SW'ly winds for the UK and on into into Scandinavia, 850's 5-10c, by the 3rd January heights have been pushed further away leaving the UK in a cool PM westerly and sub zero 850's which would make a refreshing change!

Well if the high isn't going to get sufficiently north then I'd be happy to see the back of it. At least a cool PM flow might finally deliver some snow to the ski resorts.

[January Snowstorm]

The evening runs should let us know which direction we go post Christmas.

The weather around Christmas itself looks very underwhelming. ...

 

[Mucka]

1 hour ago, nick sussex said:

Its the same old story this morning with the shortwave phasing game of poker leaving us with two pairs against the full house.

This makes any route to cold so much more difficult so we've gone from climbing Snowdonia to now trying to get up to the summit of Mont Blanc.

Especially frustrating as the upstream pattern has a window of opportunity but this phasing essentially stops the ridging north much earlier, any time you get a trough phasing with a shortwave energy will want to go ne and the troughing gets pulled further east at the same time.

You'll see that the ECM still has low pressure running ene towards the Great Lakes, this will then run into the UK troughing, this motion and phasing of energies will force energy off the trough. If you have the high further north and west you would have a decent chance of energy disrupting off that trough se into southern Europe.

If we accept that we're going to be subjected to more shortwave drama then you don't want the shortwave stuck too far east, if its going to phase you want it as weak as possible and as far west.

You only want this further east if it can separate cleanly from that troughing. You certainly don't want the UKMO solution!

Although there are still some decent colder ECM ensembles with a clustering taking winds round towards the east we need a lot to go right at the initial T144 to 168hrs timeframe and given recent weeks if things can go wrong they do so I'd say today that colder chances have taken yet another knock.

Theres a window of opportunity because the models do want to dig that troughing south to the west but this is likely to close if the models combine to deliver the least favourable phasing outcomes.

 

Very much agree with this.

Unfortunately all the output is going the same way at the moment re the phasing trough/low but we would see some fairly big changes if only the shortwave low would clear through the UK - ie pattern further West and better ridge alignment as you suggest.

I've not seen ECM postage stamps but the ensemble graph suggests that the cooler flow would now be more South Easterly/continental whereas the colder runs of yesterday evening were more likely from N/NE flow from a more pronounced ridge and pattern further West  which if correct would mean the ensembles are also moving away from any chance of avoiding the phasing of low pressure over the UK.

If nothing changes by tomorrow evening in that regard then we are still in the long grass as far as seeking cold goes. There are small hints that we may see a renewed attempt at building heights NE in the first week of January which may occur further West but mixed signals there at the moment and as you say, if we aren't going to get favourable upstream pattern then we may be better off getting rid of the sceuro high and hoping for colder zonal pattern to emerge. for now though I think we should hope to hold on to any high pressure to our East as another attempt in first week of Jan would be reinforced and then there would be good prospects of undercut and getting any blocking into more favourably positions/higher latitudes.

Some great posts today, thank you all.

Edited December 20, 2015 by Mucka

[Liam J]

23 minutes ago, nick sussex said:

Well if the high isn't going to get sufficiently north then I'd be happy to see the back of it. At least a cool PM flow might finally deliver some snow to the ski resorts.

Me too, it's not doing us any favours at all, relentless, unless you like the current weather! If the ECM monthly is right then things will get more interesting into January towards mid month! But that's a heck of a long way away and we'll be halfway through winter! 

[Frosty.]

3 hours ago, Mucka said:

 

Very much agree with this.

Unfortunately all the output is going the same way at the moment re the phasing trough/low but we would see some fairly big changes if only the shortwave low would clear through the UK - ie pattern further West and better ridge alignment as you suggest.

I've not seen ECM postage stamps but the ensemble graph suggests that the cooler flow would now be more South Easterly/continental whereas the colder runs of yesterday evening were more likely from N/NE flow from a more pronounced ridge and pattern further West  which if correct would mean the ensembles are also moving away from any chance of avoiding the phasing of low pressure over the UK.

If nothing changes by tomorrow evening in that regard then we are still in the long grass as far as seeking cold goes. There are small hints that we may see a renewed attempt at building heights NE in the first week of January which may occur further West but mixed signals there at the moment and as you say, if we aren't going to get favourable upstream pattern then we may be better off getting rid of the sceuro high and hoping for colder zonal pattern to emerge. for now though I think we should hope to hold on to any high pressure to our East as another attempt in first week of Jan would be reinforced and then there would be good prospects of undercut and getting any blocking into more favourably positions/higher latitudes.

 

I'm currently seeing nothing in the models to be encouraged about from a coldies perspective, cooler and fresher at times just doesn't cut it for me in late december and the 6z was more mild mush south of scotland. I didn't post yesterday, just read the optimistic posts but i'm utterly depressed by the latest output but still hopeful for next year as we will start with a clean slate. The mild mushy pattern won't last 3 months!

Edited December 20, 2015 by Polar Maritime
To remove a large gap.

[blizzard81]

1 hour ago, Ruben Amsterdam said:

This mornings run (note that this is for the eastern part of the Netherlands, close to the German border, De Bilt is in central the Netherlands and is a bit warmer, usually) shows some colder members indeed. Mostly inversion weather in a slow continental flow, would be my guess. I also included an ensemble with wind directions which shows a tendency towards more south/easterly winds instead of south westerly wind, but this is not all convincing yet.

From top to bottom: T2m, dew point, precip., wind 10m, wind 10m gusts, cloud cover.

Many thanks for posting this Ruben, much appreciated. Fingers crossed these colder temps keep moving west