Model output discussion - 1st December onwards

[Liam J]

Unsure on the accuracy of such charts but the ECM gives a white Christmas for some! 

 

 

 

Edited December 19, 2015 by *Sub*Zero*

[Polar Maritime]

Currently no internet here so a walk up the fields in some balmy 14c temps/drizzle this morning just gets me within 3g.. No access to charts, But those seen here posted look interesting as we head into the Christmas period and beyond with the PV starting to get disrupted as they toy with the background/stratt signals. With many interesting evolutions now being model'd out at 10 days +. A very interesting period of model watching coming up after what has been an exceedingly bland start to Winter. 

[pyrotech]

26 minutes ago, IDO said:

Well ECM does love to produce awesome D10 charts, shame each run they are different. Anyway this morning its heights and WAA towards Greenland: 

  GEM At D10  

GEM looking good for a height rise as does the GFS op. However again the GEFS are trending the other way and that now includes the control run, which is now very flat with little amplification. Always the case when a wave is introduced to a stable pattern and I suppose we just have to wait till the models sort it out. What is unfortunate is that both the GFS and ECM op are notorious for over doing the longevity and latitude of these amplifications, however the experts on here are very sure we will get a Sceuro block so its a case of waiting till the ensembles catch up.

The GFS still no sign of any MJO signal for Phase 6 or 7: 

Both the AO and NAO were showing signs of going negative but now they look like they were moving into a lower positive range, but now reestablishing into a higher positive stage over time. CFS weeklies for 2 and 3 now showing the sceuro heights, as you would expect as the CFS has been leading the MJO signal:

   

As for whether this will bring anything other than mild to the UK in the short term (up till D10) is unlikely as the ECM op is showing some very mild uppers from D7-10 inclusive. If the GFS is wrong with the MJO signal then expect flips from its ensembles soon as its D10 and D12 means don't offer much hope of some propagation to the strat:

    Strat at D16: 

Hopefully the weekend's model output will resolve these issues and we will know whether the strat can get a prolonged attack as currently the strat, although stretched is proving resilient. Its the long way to an SSW via a stretched PV I think. As stated before the experts believe the MJO is very quiet at the moment and that MJO models will flip back into the COD with more runs: https://twitter.com/xerophobe_ww/status/677975990656630785 , so what will actually happen is still debatable till this MJO signal is resolved, as if it is a fast Kelvin wave then it may be a brief meridional flow?

ECM was the only model going for a strong phase 6 and it would appear that its moving towards a weak signal even if it gets to phase 6 it will be a weak affair that has little effect

http://www.globalweathersystems.com/MJO.htm

 

[bluearmy]

If sylvain is viewing, I note the ECM parallel is now showing some data on weatherbell re surface conditions. No charts re slp or heights etc.  would be good to see the para ECM op on meteociel to compare with the para gfs. 

[Iceaxecrampon]

1 hour ago, legritter said:

Just popped in before mad saturday shopping ,and certainly some nice looking  interesting and eye candy charts this morning .

Ecm could lead us into something more seasonal but we need high pressure a bit further north but at least its being modelled and also some interesting low pressure around ,our forum will certainly not be boring but later further outlook still not sorted , looking better now from a coldies view so thats good 

 

+144 30% chance of snow (yes I know they are scant predictive charts) 1800ft asl Helvellyn area if your feeling festive.

Usual suspects around Aviemore and Fort Augustus more so if you want a decent car journey

 

 

Edited December 19, 2015 by Iceaxecrampon

[Duane S.]

Well the ECM op has lifted the spirits a bit this morning, with a very interesting take on things.The ridge likely still to be flattened if it continued but you could see a further and more serious bite at cherry emerging 1st week of Jan.

Amazingly D8 is nearly a cross polar flow...

Fingers crossed this is the start and turns into a trend in the coming days.

[Liam J]

Looking chilly towards the end of January on the CFSv2 members, these are average 2m temps, some brutal cold to our north east into February! But it is the CFS so pinch truck load of salt...

 

Edited December 19, 2015 by *Sub*Zero*

[Iceaxecrampon]

Cumbria GEFS temp ensembles take a dip - yes charts looking more seasonal but can we really expect a major pattern change after the week we had  - it's going to be a pretty close call.

 

Edited December 19, 2015 by Iceaxecrampon

[Iceaxecrampon]

58 minutes ago, *Sub*Zero* said:

Looking chilly towards the end of January on the CFSv2 members, these are average 2m temps, some brutal cold to our north east into February! But it is the CFS so pinch truck load of salt...

 

Lordy - I thought you were serious at first - a truck load indeed but not for the paths

[Liam J]

By T270 the ECM control has a 1032mb high over Norway but with a large deep trough west of the UK we have a flow coming up from Spain! Later on in the run the high gets shunted eastwards with PM westerlies into the UK in time for new year. 

[bluearmy]

as IDO mused earlier, the question re the sceuro rodge is whether it will verify as strongly as the ecm eps say or the gefs. currently the gefs drifting towards the ecm on the 06z but that could just be a pendulum swing from a specific suite.  granted that the eps push the ridge east towards the back end of week 2 but that is open to question if the ridge establishes strongly by day 10. we know the lower res ens will generally want to dismantle a block too quickly.

[TomDav]

Another perspective of ECM 00Z 850s for Christmas day;

[phil nw.]

33 minutes ago, bluearmy said:

as IDO mused earlier, the question re the sceuro rodge is whether it will verify as strongly as the ecm eps say or the gefs. currently the gefs drifting towards the ecm on the 06z but that could just be a pendulum swing from a specific suite.  granted that the eps push the ridge east towards the back end of week 2 but that is open to question if the ridge establishes strongly by day 10. we know the lower res ens will generally want to dismantle a block too quickly.

That is quite a strong day 10 signal from the ECM mean for that Sceuro ridge BA.

I am not sure if in the short term it will do us any favours as it will do little to change the overall mild south westerly flow.

A couple of days ago the MJO forecasts looked encouraging for some quick movement at decent amplitude towards phase 7 which would have signaled a change to some high latitude blocking.This seems to be stalling currently and some forecasts like the gefs are seeing it fading further west in the Pacific.

There are some confliting signals on the sort of amplitude to the Scandi/Euro high but all suites go for it post Christmas,at least for a while.

If we look at the other ens today then there seems to be a sign of shrinking the Greenland trough and raising pressure from the continent towards the UK, beyond day 10.

Both 00z naefs and to more of an extent this mornings gefs006z run.

perhaps with a move east with those lows to the north, which suggests the amount of ridging to the east will be limited by the jet across the top.

It does look  unlikely that the Atlantic will undercut any Scandi ridge now with the way things are shaping up.

I think for now we continue with this setup through to NY but with the jet a little further south at times seeing the cool down shown in the ens graph

so gradually we lose the exceptional warmth but nothing really cold is yet on the horizon rather a dip towards more normal temperatures,especially further north.

[Mucka]

RE ECM ensembles

 

That is the best signal for cold we have had in a long time from around the 27th and it has been gathering strength the last couple of days although it is still not the favoured (majority) option. definitely a bit of a split there though so I just hope that trend can continue this evening rather them just converge to mild.

Edited December 19, 2015 by Mucka

[mcweather]

Much as I hate this awful mild muck that we have been stuck in for the last six weeks. I think we may have to get through just a bit more of it yet

before we see a real pattern change ( as opposed to a sceuro ridge that flatters to deceive while maintaining the mild flow).

Most of the sensible long term forecasts ( as opposed to Excreta weather) have spoken about a mid Jan/late Jan change to a colder pattern and that still seems the most realistic outcome for me.

If we are going to see a mid Jan change to cold then it won't be until perhaps just into the  newyear that a consistent shift ( that gathers pace and ensemble members with time) might begin to appear in the gfs  FI output. So for the moment its a case of sitting tight.

Interestingly Adam Scaife. One of the met office head honcho's was quoted yesterday in article about the current exceptional mildness. He mentioned that El Nino winters are often frontloaded with mild and backloaded with cold and suggested that this winter colder than average temperature would be more likely occur in February and March. This would tie in with a gradual pattern change via ssw starting mid/late Jan.

 

Now let me see when was that famous winter that saw a pattern change mid/late Jan and then the coldest temperatures occurring in Feb and March?.............

 

 

Edited December 19, 2015 by mcweather

[Daniel*]

Vortex looking distressed on 00z ECM T+240 our salvation, Eastern Europe going into the freezer; we are starting to see some much more encouraging model output. The foundations for a much colder outlook post new year I believe.

I'm quite assured we'll eventually join in with our eastern 'counterparts' - a little patience goes a long way? I sense the month will turn out decidedly different and markedly colder to how December 2015, has panned out I have gone for a cold figure of 2.1C for the January CET.

Towards the end of month divergence arises albeit there are tentative signs of a trending negative NAO post the new year...opening up closed doors? 

Edited December 19, 2015 by Daniel*

[Bullseye]

Could it be? Also take a look at few replies even one from our very own Ed.

Edited December 19, 2015 by Bullseye

[Mucka]

No comment on GFS 12z says it all. GEM a little better for long term prospects.

Down to ECM to keep the cold flag flying

 

EDIT

 

Ah thanks Greenland, 

Edited December 19, 2015 by Mucka

[Mucka]

Looking through GFS ensembles there is plenty of scatter and at least in their variation they show some interest.

(what is it about p7 - always seem to be among the best runs - coldies haven?)

 

[Ali1977]

7 minutes ago, Mucka said:

Looking through GFS ensembles there is plenty of scatter and at least in their variation they show some interest.

(what is it about p7 - always seem to be among the best runs - coldies haven?)

 

7 isn't a patch on 18

Edited December 19, 2015 by Ali1977

[Mucka]

2 minutes ago, Ali1977 said:

7 isn't a patch on 18

 

Very true, 7 goes wrong but it does usually show as one of the better runs for MLB and HLB for some reason.

There is still little cheer overall though from GFS for coldies but at least the scatter gives hope.

GFS ensembles have not shown any interest in potential cold from the 27th where ECM certainly have so for me it is more relevant that ECM and its ensembles keep that trend going rather than GFS jumping on board for now.

[nick sussex]

Just catching up with the outputs after a long lunch in 25c heat! astonishing temps here just under one week before Christmas.

A mixed bag overall with now some uncertainty with the main shortwave to the sw, tonights GFS/UKMO look like at least keeping it much further south before phasing likely later on.

The Christmas/Boxing Day outlook still looks uncertain, the GFS has shortwave energy further east which has most of the UK in a cooler flow, the UKMO further west with milder conditions especially towards the south.

I still wouldn't rule out something wintry around that time on the nw flank of any shortwaves if they do run into the UK. The GFS makes hard work of getting any ridge further north with a flatter upstream low and that eventual phasing with the troublesome shortwave.

The divergence between the MJO forecasts continue the UKMO wants to speed this into a high amplitude phase 6. This is supported by the statistical constructed analogue model. The GEFS BC is less interested, the ECM monthly has some clusters supporting that with some also going into phase 7.

Because of these differences we might begin to see more divergence between the operational outputs.

For the first time in many weeks we're seeing two distinct clusters in the ECM ensembles, its clear when looking at the temps/dew points/wind directions that these build in high pressure near Scandi, with the latter in the se/east/ne quadrant. The warmer cluster keep the flow more south/sw.

So we have to hope that the ECM tonight will join that colder cluster and bring something resembling winter to Western Europe.

 

[Mucka]

ECM 120 already more amplified than GFS upstream so fingers crossed.

 

Edited December 19, 2015 by Mucka

[Ali1977]

Now if I didn't know the METO are not on board for any cold in the next few weeks I would be quite happy with the ECM at 192 - could they be wrong!!

[Cloud 10]

What's the ECM up to here?