Model Output Discussion 4th Dec.2013-12z onwards.

[Bobby]

Wet wet wet over the next 8 days, 100mm+ likely in parts of the West. GFS 12z out on its own with its Christmas high, ECM 12z continuing the zonal express.

 

[ANYWEATHER]

Looks like the Ecm will have war upon Iceland Christmas day with that mega deep low , but "IF" this charts verifies at least it will usher in some seasonal weather!!!

[Summer Sun]

I think Its fair to GFS has had another bad day at the office with its 12z run

 

ECM is not backing it one jot

 

[IDO]

ECM follows GEM and BOM in disagreeing with the idea of a settled Christmas offered up by GFS.

ecm 12z @ t240

The GFS Op is certainly the extreme for a settled Christmas, but ECM appears to have moved towards that, and a middle ground is a possibility:

ECM 12z at T240: ECM 0z T240:

A shift to higher height anomalies in our locale. Tentative but a maybe? The reason appears to be that at around D8 both models are picking up on energy dissipating from the Greenland vortex and heading towards Siberia, giving a respite to the energy feeding the jet. The GFS then has the vortex regrouping into one blob and the jet fires up again (D12), and the zonal flow perks up.

ECM:

GFS:

The GFS 06z did not show this distribution of Greenland energy hence the zonality:

Timing and strength of any temporary ridging of low confidence, assuming this respite remains, so this may indeed be a trend.

Edited December 15, 2013 by i'm dreaming of...

[davacr123]

Off topic but weather related britains killer storms on channel 4 now

[OldMetMan]

The GFS today is swinging wildly today, although there is some consistency in the early runs in the last few days, and up to the medium-term, the GFS and other models maintain the zonal unsettled theme, with just daily variations in the timing and intensity of LPs.

There are few clues currently as to if and when the unsettled theme will change but the consistency in GFS runs I mentioned I suppose could be called a trend, with gradual falling heights and associated falling pressure over much of the central and eastern Atlantic, as well as falling thickness values and lower temperatures.

Further W over N America, there are signs of a more amplified although probably quite transient amplification of the flow. The upper vortex over the E of the US seems vigorous enough to maybe push some ridging up ahead of it in the W Atlantic, which might favour the GFS's idea of falling heights further E in the longer term.

The only other configuration I find promising at this stage is there is a certain amount of blocking over the N Pacific as well as quite a respectable upper ridge over the E Pacific, which may, I think, be indicative of a longer term tendency towards more widespread blocking around the hemisphere. But that is a long way off, with so much energy pushing systems towards the UK, continuing unsettled and most probably stormy conditions seem to be the story for some time yet. Indeed, with the very deep LPs we're seeing at the moment, we may well see potentially damaging winds at some point in the next 2 weeks or so.

One last thought: continental HP over N Europe/Asia keeps appearing from time to time on the longer term model runs, so once again I am still inclined to believe in the possibility of northern blocking, as I keep on saying! A few more runs from the GFS are needed to see if the trend, such as it is for falling heights, is maintained.

[draztik]

Im dreaming of, you may well be right... the gfs ens do show a lot more scatter, and more members want to edge higher pressure into the UK by Christmas (certainly more than on the 0z run). I'll reserve judgment until I see the ext ecm ensembles. Tho as already stated, the ensemble mean from GFS still goes with a generally unsettled outlook over the festive period and beyond.

[Gibby]

Good evening. Here is the report on the midday outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Sunday December 15th 2013.

 

All models show a changeable and sometimes wet and very windy spell of weather throughout the coming week. Day to day the weather will vary between wet, windy and mild days with tonight, Wednesday and Friday favoured for this weather type while later tomorrow, Tuesday and again on Thursday sees some colder conditions with dry weather for many on Tuesday while Thursday sees very showery weather with some colder weather in tow too with some temporary wintry showers on Northern hills.

 

GFS shows an unsettled weekend to come with rain and showers in brisk and locally very strong West or SW winds with showers, wintry on Northern hills. A change is shown tonight though as High pressure builds north from France over the Christmas period and allows very mild and drier weather to become established for a time across the South with less rain for the North too before changeable Atlantic type conditions return to all late in the run with temperatures holding up very well with most rain in the North and West.

 

UKMO closes it's run tonight with next weekend looking like being a wet and windy one as well as becoming very mild once more as a broad and strong SW flow is well set across the UK with troughs rushing through at times.

 

GEM again tonight shows a very unstable Christmas period with strong winds and rain at times for all and again tonight the model indicates somewhat lower temperatures with time allowing some snowfall in the squally showers occurring over the Christmas period.

 

NAVGEM also shows wet and very windy conditions next weekend and to end it's run with temperatures well up in association with the near gale or more WSW wind.

 

ECM tonight also shows a trend towards High pressure building back briefly from the South in the few days up to Christmas before Christmas itself looks like a mild and wet one with rain followed by showers on a gale West or SW wind.

 

The GFS Ensembles are edging towards another milder phase now as we approach and carry through the Christmas period although the operational version I described above was a bit of an outlier at this point. None the less there is still little sign from any member of anything remotely in the way of snow and ice in a big way.

 

The Jet Stream shows the flow across the UK through all of this week before it has introduced a short shift North again as we move towards and over Christmas before returning South on a West to East axis late in the run.

 

In Summary the indications are for the weather to stay relatively mild for the foreseeable future with plenty of rain at times with strong to gale force winds too on occasion. If anything tonight the prospects for a deeply unsettled and colder Christmas has receded somewhat tonight as High pressure builds back North towards Southern Britain from France in the days before Christmas before things turn mild, wet and windy again over the period itself. With pressure remaining High over Southern Europe winds will remain from the West for some considerable time aided by a powerful Jet stream. Day to Day differences in daily detail will change regularly over the coming days but there is little change expected in the overall pattern.

[lorenzo]

ECM has the Christmas low at sub 915mb (913mb on the higher res, but the public offering has it sub 915mb), its just that Meteo can't handle pressure that deep.....

Scary really.

 

 Unbelievable.. Braer Storm all over again.

[tinybill]

just looking  at  the  models  till deep f1  its  looking  a  bit  wild,  plus all eyes should  be on Emily  she  could  be  a rather  naughty  girl this  week

[stewfox]

Only an eternal optimist could find something positive to say I'm afraid.

 

 

Always been a half full person but it is a stuggle a present thats for sure based on current model out put.

Edited December 15, 2013 by stewfox

[nick sussex]

Tonights model output needs to come with a health warning for coldies. The models have generally moved away from developing some polar height rises and we're left with the GFS Euro high edging north or the ECM low  at T240hrs.

 

For coldies its like saying would you rather get shot or hung, they're both underwhelming from a cold perspective. With no polar height rises theres nothing to force the jet into a more palatable nw/se axis.

 

The driver the PV over ne Canada will just sit there spawning depressions or as the case maybe depression in here until it either disrupts or relocates much further to the nw.

 

It's like we're fighting the Alien(PV), someone fire it out of the airlock!

 

Final report of the commercial starship Nostromo . Third officer reporting. The other members of the crew, Higher Latitude Blocking, Upstream Amplification,Negative NAO are dead!. Cargo and ship destroyed. I should reach the frontier in about two weeks. With a little luck, the PV will get lost. This is Ripley, last survivor of the Nostromo, signing off!

 

That's my alternative take on tonights models, as a kindness to coldies I'm discontinuing my cold/snow ratings and sledge rating until these move away from the flatlining position!

Edited December 15, 2013 by nick sussex

[Summer Sun]

Its pretty much as you were from the ECM ensemble with deep lows the main feature

 

[Nick L]

Off topic but weather related britains killer storms on channel 4 now

 

Guidance to all: If your post has to start with "Off topic but.." - don't post it!

[Captain Shortwave]

It's like we're fighting the Alien(PV), someone fire it out of the airlock!

 

Final report of the commercial starship Nostromo . Third officer reporting. The other members of the crew, Higher Latitude Blocking, Upstream Amplification,Negative NAO are dead!. Cargo and ship destroyed. I should reach the frontier in about two weeks. With a little luck, the PV will get lost. This is Ripley, last survivor of the Nostromo, signing off!

 

That's my alternative take on tonights models, as a kindness to coldies I'm discontinuing my cold/snow ratings and sledge rating until these move away from the flatlining position!

Or we could just do the sequel and nuke the PV from orbit!!! 

ECM ens seem to back it's operational up to day 10 at least.

Edited December 15, 2013 by Captain shortwave

[UV-RAY]

Always been a half full person but it is a stuggle a present thats for sure based on current model out put.

Yep tonights model output has taken a huge slurp out of my half full glass.

[IDO]

Its pretty much as you were from the ECM ensemble with deep lows the main feature

 

Yes the ECM mean is a shocker. Seemingly little support for anything close to a settled Christmas. Hopefully the GFS is onto something, but nominal support presently.

[terrier]

Well been away for a few days now. And have returned to see nothing really has changed. Apart from a few fleeting glimpses of polar maritime air that will be very short lived. Then we are back to wet and windy weather. Think this winter we could be looking at a early 90s winter with wet windy weather been the dominant feature. But at least it means a certain person will look very stupid. Sorry mods couldn't resist!!!

[nick sussex]

Or we could just do the sequel and nuke the PV from orbit!!! 

ECM ens seem to back it's operational up to day 10 at least.

This always happens, for some reason the limpet PV causes me to come out with my rather theatrical postings, if this carries on much longer I dread to think just how many film quotes I'll be subjecting this thread to!

 

Yes the ECM is resolute in its troughing over the UK , I'd tend to disregard the GFS 12hrs operational run as being on its own and not supported, quite strange to see it picking that solution given its progressive bias.

[Biggin]

I agree SI, just thinking back to this time last week and the models were showing a benign, mild stagnant snooze fest with a mega limpet euro high..it looks more like winter now.

Yep stuck on the edge of high pressure for weeks on end was the vogue, good to see the models being very active ie past 5 days no idea.

[Yarmy]

Blimey, been away for a week and last time I looked we were heading for North African feed euro highs. Now it's huge Atlantic storms. Interesting from a model-viewing perspective, but not the cold most of us are chasing.

[Skeggy Winter Storm]

Well been away for a few days now. And have returned to see nothing really has changed. Apart from a few fleeting glimpses of polar maritime air that will be very short lived. Then we are back to wet and windy weather. Think this winter we could be looking at a early 90s winter with wet windy weather been the dominant feature. But at least it means a certain person will look very stupid. Sorry mods couldn't resist!!!

One thing tho its only december 15 just about 3 months in front of us to go this time last year models were awfull and it turned out ok if it was mid february then yes id agree but now nope

[nick sussex]

If I'm reading the ECM ensemble spread correctly then the tiniest of straws perhaps!

 

 

There looks like theres a cluster of solutions that bring low pressure further south, to the ne perhaps some weakish pressure rises given the spread up through Svalbard.

 

Not a great deal of spread over Greenland itself so we can assume that low heights remain there.

 

I see BA's in the house what do you think?

 

I've added in a few more bits of detail, the Siberian ridge probably a little overdone but the general gist is that troughing is very likely near or over the UK, because low heights look to remain to the nw, the spread there can't be high pressure over the UK because if you follow the spread from earlier it  certainly suggesting a developing low runs east and phases with low heights to the nw, we know the ridge is there in Siberia, the area to the north near Svalbard is a plausible area that we could see a bit more influence from the Russian side.

 

Still nothing that wintry may come of this if the troughing is unable to clear east/se but anyway just perhaps a bit of interest:

 

 

 

Edited December 15, 2013 by nick sussex

[legritter]

I think interesting times are ahead Model watching with each daily run of all Models giving us plenty to discuss. Todays GFS run was a complete turnaround but at that range it can be expected ,although the 528 dam wasnt that far to our north so i expect some  interesting output to crop up soon .Tonights ECM was about as i expected it .But i must admit it is looking hard to get out of this current synoptic situation ,that is if thats what you want .so the weather is certainly not boring and plenty of time for many weather types to emerge over the coming winter months ,

[draztik]

Looking at the ext ecm ensembles this evening, we see a massive contrast to what the gfs op is showing at the same timeframe. Here is the ensemble mean at t240

the 10-15 day mean continues with its recent trend. Troughing over the UK. If we are to take the ens at face value, its hard to see a way out of this unsettled theme.

10-15 day height anomalies

Edited December 15, 2013 by draztik