Model output discussion - 1st December onwards

[Nouska]

On ‎12‎/‎12‎/‎2015 at 11:33 AM, Nouska said:

With all the discussion about mid-range mean charts, as an experiment in verification, I'm following the ECM means for Christmas day - still maintaining a signal for 'cold zonality'  (hate the expression but everyone knows what it means).

Charts for mid-day on the 25th.

850 temp     Z500 

I would argue, that at this early stage, quite good agreement from the two main models.

GFS showed the stormy Christmas/Boxing day of 2013 way out at far reaches and consistently brought to time.

Time to have another look at whether the ECM ensemble mean is progressing its early signal for cooling around Christmas.

                                     

Looks to be progressing the signal as shown with minor tweaking - so far, upper air temps in the UK looking to verify well.

[Glacier Point]

So the CFS and EC weeklies are in reasonable agreement.

Week 2 very solid agreement (and EC EPS and GEFS) on Sceuro ridge. CFS persists this into week 3, EC not so keen. Either way, a good period of Wave 2 upcoming (and typically GFS showing this (rushed) manifested in some operational outputs).

Week 3 to 4 transition with a more westerly / NW'ly component with EC more bullish on the upper trough extending into Scandinavia. Essentially both being driven by the same tropical forcing pattern, so understandable that they're so alike at this range.

Both EC and CFS showing  week 4 indication of cross polar +ve height anomalies developing Siberia to Alaska. Not ideal for deep cold getting to Europe fast, but stratospheric developments may be unfolding and influencing the pattern by then. Broadly my week 3 and 4 attention to any developing ridges over Canada and sub-tropical flow over the southern US, and of course, stratosphere from 11th January onwards.

Edited December 18, 2015 by Glacier Point

[Frosty.]

Time to look closer at tonight because records could be smashed! This is really more like warm summer nights after a BBQ with temps tonight rising rather than falling, 15c 59f minima and then tomorrow reaching 16/17c 62f in places. It's remarkable even if you hate it like I do!

[Frosty.]

19 minutes ago, Snowmut said:

Yes just as you thought it couldn't feel any less like winter,a Sahara dust cloud is heading our way!!

Still at least  snow shovels will get some use,......Shoveling bloody sand!!!!

Yeah I forgot to mention the saharan sand..my bad...anyhoo it would be interesting to read steve murr's thoughts on the december heatwave..lol

This is truly the nadir for coldies across the uk according to the latest models but I think we start with a clean slate in January with wintry spells to look forward to this winter despite some comments saying otherwise!

 

[nick sussex]

Currently sunny and 21c here! Shorts back on! Lets hope tonights ECM can keep the Santa spirit . The GFS 06hrs run did edge a little way towards that but its troughing was still less amplified.

In a nutshell that's what will be the deciding factor to get the Euro slug vile vermin high further north. I'm wondering whether the different amplitudes of that troughing are responses to different MJO forecasts.

Not long to wait now, come on GFS and other outputs remember its Christmas, you know it makes sense!

[Mucka]

Not far from a split

 

 

Not too bad really considering where we are now but let's hope ECM can deliver some holiday cold.

Edited December 18, 2015 by Mucka

[Singularity]

That trough is stalling further and further west on each new GFS det. run and GEM's coming around to the idea too. Perhaps ECM was onto something this morning.

If so, we may get a more seasonal feel to things for Boxing Day - but with the Dec CET being dragged down quite a bit as nights fall close to freezing and the days are widely in the mid-single digits. Probably not enough to prevent the record from being taken, but still... I suppose it may be more of a deal here as it could prevent the novelty of a Double-Digit December. Oh the irony!

 

Longer term, good to see signs of decent interference with the vortex from wave breaking, coupled with that trend to shuffle the pattern a bit not long into the new year - maybe too progressive from GFS but then again, exceptions do happen!

[nick sussex]

The GFS sort of listened to my desperate pleading! Not bad at least there might be some drier and sunnier conditions with overnight frosts.

Its similar in pattern to the ECM 00hrs run in terms of shortwaves running ne at around T192hrs, probably not enough cold air in place on this GFS run to provide snow but something to keep an eye on over future outputs if this trend continues.

Still these better synoptics are well past the more reliable timeframe and so it might still go pearshaped but lets hope for a bit of luck.

 

[Cloud 10]

1 hour ago, Greenland1080 said:

GEM had an upgrade Tuesday

 

 

 

Yes,quite a major upgrade for the GEM and seems its all about ying and yang!

http://dd.meteo.gc.ca/doc/genots/2015/12/14/NOCN03_CWAO_142125___00050

 

Hopefully this will improve its rather poor 850hpa temperature verification.

 

 

[IDO]

The GFS op still struggling with the upcoming amplification and another run that we should bin. The 2m temp plot is a big outlier:

     

The mean T850s show mild uppers from D7-D16 plus:  

That may not be what we want but if we can get some of that WAA up to higher latitudes we should see some good trop to strat warming. If the mean is a guide then we should continue with a mild December though placement of the ML HP cell/ridge if the op is correct would dampen the temps. As it stands the GFS op and has small cluster support, with the main location of the mid latitude HP cell in Europe as per the mean:

D10 mean:   This has been very consistent despite the op going  a bit erratic.

The ECM 0z had little support and has backtracked for Christmas Day, now a milder flow:

Edited December 18, 2015 by IDO

[The PIT]

1 hour ago, nick sussex said:

The GFS sort of listened to my desperate pleading! Not bad at least there might be some drier and sunnier conditions with overnight frosts.

Its similar in pattern to the ECM 00hrs run in terms of shortwaves running ne at around T192hrs, probably not enough cold air in place on this GFS run to provide snow but something to keep an eye on over future outputs if this trend continues.

Still these better synoptics are well past the more reliable timeframe and so it might still go pearshaped but lets hope for a bit of luck.

 

Mmmm ECM doesn't seem to listening so much a little bit of wax in it's ear.  Although the difference is marginal is erring on the milder side unfortunately. Would have been nice too see some -4 uppers all the way across the country on the 25th. 

Not sure whether it's just a slight tease from the pair of them too be honest.

[gottolovethisweather]

25 minutes ago, IDO said:

The GFS op still struggling with the upcoming amplification and another run that we should bin. The 2m temp plot is a big outlier:

     

The mean T850s show mild uppers from D7-D16 plus:  

That may not be what we want but if we can get some of that WAA up to higher latitudes we should see some good trop to strat warming. If the mean is a guide then we should continue with a mild December though placement of the ML HP cell/ridge if the op is correct would dampen the temps. As it stands the GFS op and has small cluster support, with the main location of the mid latitude HP cell in Europe as per the mean:

D10 mean:   This has been very consistent despite the op going  a bit erratic.

D10 mean with mid latitude HP cell in your example above, yeah, but if there were a D16 mean I would strongly suggest the HP cell would be rather dominant across Scandinavia/NE Europe rather than where its been for what seems like weeks upon end. 

IDO, I do foresee that in a week or so's time your posts will be bringing us much joy i.e. post Christmas cheer to over 90 percent of this forum's followers, that being the cold brigade.  By then, the trend alluded to by GP, Phil NW and several others will surely be our friend. No, I'm suggesting entrenched bitter cold anomalies and snow-depths of twenty feet, just something merely a wee bit more seasonal. I say, bring it on, keep a close eye on the ECM for a possible first hint at this?

 

Happy Christmas to one and all, even if does turn out to be a mild mushy one, there could be some hilltop/mountaintop snow yet for some. 

 

Edited December 18, 2015 by gottolovethisweather

[nick sussex]

16 minutes ago, The PIT said:

Mmmm ECM doesn't seem to listening so much a little bit of wax in it's ear.  Although the difference is marginal is erring on the milder side unfortunately. Would have been nice too see some -4 uppers all the way across the country on the 25th.

Not sure whether it's just a slight tease from the pair of them too be honest.

The ECM evolution is very similar upto T192hrs, its how the models deal with that shortwave energy near the UK that causes the problem on the ECM 12hrs run. We still have the digging trough to the west and there are now differences appearing upstream at T144hrs between the big 3 in terms of amplification.

The ECM T216 and T240hrs could go one of two ways, lets hope Santa hasn't put the phone down.

Well there was some crackle on the line but Santa is still listening! Nearly everything that could go wrong did and the ECM still managed to dig the trough and build pressure north.

It also split the PV which is miraculous given what you'd expect to see given the background signals.

Edited December 18, 2015 by nick sussex

[Cheshire Freeze]

8 minutes ago, nick sussex said:

The ECM evolution is very similar upto T192hrs, its how the models deal with that shortwave energy near the UK that causes the problem on the ECM 12hrs run. We still have the digging trough to the west and there are now differences appearing upstream at T144hrs between the big 3 in terms of amplification.

The ECM T216 and T240hrs could go one of two ways, lets hope Santa hasn't put the phone down.

First solid signs now that the vortex may be about to run into some trouble...

 

[Cloud 10]

9 minutes ago, nick sussex said:

The ECM evolution is very similar upto T192hrs, its how the models deal with that shortwave energy near the UK that causes the problem on the ECM 12hrs run. We still have the digging trough to the west and there are now differences appearing upstream at T144hrs between the big 3 in terms of amplification.

The ECM T216 and T240hrs could go one of two ways, lets hope Santa hasn't put the phone down.

 

Looks like he wants to talk some more.

 

 

[Methuselah]

GFS's New Year will be in low resolution due to fewer flights and weather balloons.

[Daniel*]

T+96

T+240

Comes to mind...

[nick sussex]

Well after the evenings outputs some cause for optimism but still a long way to go.

The ECM T240hrs is a nice chart but we'd want to see a more negative tilt to the troughing to the west and a bit more dig se'wards.

I think we have a small window of opportunity because theres high confidence in renewed amplification over the Pacific this will effect the movement of the PV.

The digging trough to the west needs to be further west and we don't want phasing with shortwave activity near the UK, without that phasing between T168 and T192hrs we would have seen a stronger ridge pushed north.

So I think my fellow  coldies its down to that never shredding and biting of finger nails time for the next few model outputs.

[gottolovethisweather]

32 minutes ago, gottolovethisweather said:

D10 mean with mid latitude HP cell in your example above, yeah, but if there were a D16 mean I would strongly suggest the HP cell would be rather dominant across Scandinavia/NE Europe rather than where its been for what seems like weeks upon end. 

IDO, I do foresee that in a week or so's time your posts will be bringing us much joy i.e. post Christmas cheer to over 90 percent of this forum's followers, that being the cold brigade.  By then, the trend alluded to by GP, Phil NW and several others will surely be our friend. No, I'm NOT suggesting entrenched bitter cold anomalies and snow-depths of twenty feet, just something merely a wee bit more seasonal. I say, bring it on, keep a close eye on the ECM for a possible first hint at this?

 

 

 

 And it is as if tonight's ECM has read the script, my script that is. 

 

Baby steps and tis but only one run, nonetheless the signs are there for something better, colder, drier and sunnier at least post Christmas. Might help keep nature and its pests in check, who knows we might even get a frost for once down in tropical Southern England. My bets for the big day (Christmas Day) now would be for a wet out West, drier towards the East type scenario with mostly average Temperatures, always warmest towards the South and West. As for snow, only on those ole Christmas movies I reckon , Boxing Day might offer more hope for those at elevation.

 

Edited December 18, 2015 by gottolovethisweather

[Midlands Ice Age]

6 minutes ago, Daniel* said:

T+96

 

Comes to mind...

Brilliant Daniel

+100

[Methuselah]

9 minutes ago, Midlands Ice Age said:

Brilliant Daniel

+100

Indeed! https://www.youtube.com/watch?v=76RrdwElnTU

[reef]

Tomorrow now showing on the NMM short range high resolution model (available on netweather extra) showing 17C in places tomorrow:

A good chance of the record going, exceptionally mild weather for December.

[Iceaxecrampon]

Stopped short of saying it  - but this really is blowtorch stuff at the moment

59 members online says a lot.

Festive noon frost for mid Ireland  - nearly an ice day you lucky bu##ers

Edited December 18, 2015 by Iceaxecrampon

[ANYWEATHER]

Hi Folks, Friday Again! This time next week will be the Big Christmas day and there are Chincs of light amongst the doom and gloom of model output! It looks like turning seasonal if not briefly colder then normal during the festive period...its a long way off but some people will see a WHITE CHRISTMAS  , but very interesting model watching  nonetheless

[Froze were the Days]

1 hour ago, CreweCold said:

First solid signs now that the vortex may be about to run into some trouble...

 

Doesn't mean anything - PV wasn't in control of our weather the first week or so of November but we still had very mild conditions. ok not full on Atlantic stuff but so far this late Autmn/early winter has 'found ways' of continuing this mild headache!