Model Output Discussion 17th Dec.2013-12z onwards.

[Frank Trough]

is that the windiest GFS op ever?! (i know - it isn't really, but blimey...). surely that's the most startling thing from the GFS tonight?

 

 

 

 

 

 

etc etc.....

 

 

is anybody going to have a fence left by 2014?

Edited December 17, 2013 by New Forest Gump

[syed2878]

what interests me is that how jh is sniping when he is telling it how it is. Surely it's better than hopecasting and misleading new folks too. Well going by the 12z gfs it's going to be wet christmas than white1 apart from northern highground and possibley low levels as well.

[Steve C]

Don't you dare start limiting your input John, you are one of the most valid people on here and have put a heck of alot into the site.

I understand your frustrations, but rise above and carry on ay? I for one don't want you to stop giving us your amazing experience 

Here, here!

[legritter]

Relentlessly Zonal from start to finish

A lovely cold High over Siberia (luck sods!) with an awesome huge airmass circa -40 very extensive. Canada of course, not too shaby either.

 

 

No good in the slightest to the UK as it's all blasted east courtesy of the limpet vortex which has got a life tenancy over Greenland etc and bathes us in mild wet stormy rubbish.Or at over two weeks away it is totally wrong .Interesting times ahead with many IFS and 10WEEKS OF WINTER LEFT .

[legritter]

Sorry my previouse post was posted incorectly ,clicked on wrong quote i think .

[phil nw.]

Yes those heights were promising, Russian, N. Pacific and polar heights: gfsnh-0-288.png

 

But there was an inevitability about it. So much PV energy, you squeeze one part of the NH it will power up the lower heights elsewhere and flatten the pattern: 

 

gfsnh-0-384.png

 

In this instance the Pacific ridge is quelled by the energy in the form of lows, spinning off the bottled up NE quadrant of the NH. Thus the jet is re-invigorated and off we go again, repeat and rinse pattern. What IB warned us of.

 

Till the PV loses some of its bite, any transitional HLB is going to be of little help unless we lose the Greenland blob, seemingly the only part of the PV that is omnipresent, meaning any cold flown in on the jet from the Canadian vortex is washed out time it finishes its N. Atlantic crossing to the UK.

 

Just further to this i'm Deaming of... and this for newer model watchers we can see the how cold the vortex is by the all the blue and purples in the 500hPa pattern.

This indicates the strength of the polar vortex over the Arctic regions which drives the westerly pattern around the hemisphere down to mid-latitudes.

Any warming and thus weakening of the vortex will show up as yellows and oranges splitting the vortex and disrupting it's profile.Here is an example from January 2010

 

a classic Greenland high.

When we see this sort of development ie blues/purple colours  being infiltrated by those yellows/oranges then we know that some warming and weakening of the pv is underway and some high latitude(Arctic blocking }high pressure is building.

At present any warming is skirting the Stratosphere such as seen around Asia at mid-latitudes but not yet getting into the core of the polar vortex.

The Stratosphere is at it's coldest now and the very deep blues/purples over the Arctic in the 500hPa modeling reflects this.

[Captain Shortwave]

Showery Christmas day according to the ECM, temperatures cool but not overly cold. Boxing day looks like being something truly awful though.

Edited December 17, 2013 by Captain shortwave

[Costa Del Fal]

 

Showery Christmas day according to the ECM, temperatures cool but not overly cold. Boxing day looks like being something truly awful though.

 

Wasnt it yesterday that the Vortex was forecast to be pushing East by Boxing day. Seems to be being pushed back?

Edited December 17, 2013 by Blizzards

[nick sussex]

Lets hope the ECM will keep up its recent reputation of being wrong past T168hrs as it reforms the PV into one blob to the north. The best output at T144hrs of the big 3 is the UKMO, the GFS and then the ECM third, at 144hrs its already dropping heights to the ne whereas the UKMO still has some influence from the Siberian ridge.

 

As soon as the UKMO further outlook mentioned chance of snow for especially the north that jinxed it because the ECM is dire in its FI.

[Cloud 10]

Yes,some boxing day madness from the ECM this evening with its super-low.

 

 

 

The JMA wants it a day earlier.

 

http://www.meteociel.fr/modeles/jma/runs/2013121712/J192-21.GIF?17-12

[Gibby]

Good evening folks. Here is tonight's look at the NWP output taken from the midday runs for today Tuesday December 17th 2013.

 

The weather is shown by all models to be very unsettled and often very windy with gales and heavy rain sweeping across the UK tomorrow, especially later in the day and toward the NW where some storm force gusts are possible. Through Thursday the weather will turn colder and more showery with some wintry showers in the North with even a little wintriness to the showers across the hills and moors of the SW too at times. Then through Friday and the weekend the weather stays very unsettled and windy with further spells of heavy rain and it will become mild again across most areas with the North seeing slightly colder weather again on Sunday with showers.

 

GFS then shows next week as increasingly stormy with potential for damaging winds and high rainfall totals giving rise to flooding issues in prone areas over Christmas. In addition colder air will migrate slowly across Britain at times with the risk of snowfall albeit mostly transient over hills and mountains from Christmas on. Little change is then shown in the pattern through the entire run which means little significant change in the weather type until after the New Year.

 

UKMO closes it's run next Monday with Low pressure in the north Atlantic with a strong to gale SW flow with mild and wet weather extending NE across the UK early next week.

 

GEM tonight shows a very windy and wet Christmas week with incessant spells of rain, heavy at times mixed with spells of colder and more showery weather with snow on Northern hills.

 

NAVGEM also shows a wet and windy spell to start next week with some potentially stormy conditions surrounding a small daughter low crossing Southern Britain next Tuesday.

 

ECM tonight shows a very disturbed Christmas with strong winds throughout next week with rain, showers and severe gales all featuring with Boxing Day looking likely to be the worst day with severe Westerly gales and cold weather with squally wintry showers across all areas.

 

The GFS Ensembles again show no changes to the pattern that's been maintained for some time now from the GFS output. Low pressure and copious rain events coupled with strong winds remain the most important weather events over the coming few weeks with little chance of anything other than fleeting wintry showers on the hills and mountains in among the wind and rain.

 

The Jet Stream continues to have the UK in it's sights as it crosses the Atlantic across the UK and way into Europe over the coming period. The sine wave pattern occasionally pushes it further North then back South as each opposing air mass passes over the UK.

 

In Summary tonight at the risk of sounding like a broken record nothing has changed tonight. Day to day variations in the impact of storm systems is all academic as the genera message is one of wet and windy weather very frequently for all over the next few weeks with potential for some very powerful depressions delivering extremely low pressure and severe gale or storm force winds almost anywhere over the period. There is also scope for some colder polar air in the mix at times later delivering some sleet or snow to Northern and Western hills and mountains.

[Paul]

Helllooooo! This is the model thread, if you'd like to moan/ramp about the models etc, please head over the banter thread:

http://forum.netweather.tv/topic/78680-model-banter-moans-and-ramps-winter-201314/

 

Will be moving a bunch of posts over there shortly, so we can leave this thread for model discussion

[Sky Full]

Where's my arrows?

http://cdn.nwstatic.co.uk/ecmimages/20131217/12/ecm500.216.png

Could that really happen?

Finally.... I have worked out how to post a chart!

SF

[Uncle_Barty]

dear god, what sort of wind speeds would that produce??

 

That would wreck Bournemouth v Yeovil as a spectacle.....

[shedhead]

Unfortunately still no major changes in the overall output this evening. The Euro high might be getting pushed increasingly onto the ropes, but it very much looks like it's response will be to come back out swinging, with any Pm air finding it very difficult to land more than the odd glancing blow. At this stage any game changing haymaker remains a long way off. 

 

Not understanding all the current angst in here either. To my mind in winter setups like this it's the genuine weather enthusiasts that keep this thread going, not the 'it will be cold at any cost' crew.  They will all be back soon enough, so for now those of us who have an interest in all type of weather should be able to co-exist much more respectfully. 

[johnholmes]

the pdf I promised with my musings on mid term outlooks and my reasons. I hope if there is discussion about it rather than make this thread a bit disjointed we can do this in the more leisurely area where I am putting a copy of the pdf.

 

pdf using anomaly charts and current synoptic ouput 17 dec 2013.pdf

[nick sussex]

The ECM ensemble mean thankfully doesn't support the ECM operational run, makes less of the PV to the n/ne.

 

 

The ensemble spread looks to develop some pressure rises to the ne with some elongated ridging towards Svalbard:

 

 

 

[draztik]

Yup, its as you were with regards to the long range ensembles tonight - all showing major troughing, with their 11-15 day output

 

Height anomalies day 11-15 NAEFS/GEM/GEFS

[fergieweather]

 

Unfortunately still no major changes in the overall output this evening. The Euro high might be getting pushed increasingly onto the ropes, but it very much looks like it's response will be to come back out swinging, with any Pm air finding it very difficult to land more than the odd glancing blow. At this stage any game changing haymaker remains a long way off.  Not understanding all the current angst in here either. To my mind in winter setups like this it's the genuine weather enthusiasts that keep this thread going, not the 'it will be cold at any cost' crew.  They will all be back soon enough, so for now those of us who have an interest in all type of weather should be able to co-exist much more respectfully.

Wholly agree. And lest us forget that the Burns Day Storm was demonstrable (and tragic) evidence enough of just what type of 'other' extreme weather can be categorised as genuine winter fare. This upcoming week is a fascinating one - every bit as unusual and infrequent, in a broad historical timeline, as the varied deep cold set-ups craved by some folk. Whilst the latter scenario has currently zero signal in *present* model output, it's surely worth indulging interest in the here-and-now, because it's not a common scenario we see unfolding for Christmas week and will, for some, prove surely newsworthy for all the wrong reasons.

[ANYWEATHER]

Probably safe to say that Christmas day will be dominated by low pressure, but with exact details ...who knows.???.  

[legritter]

Brilliant POST BY iAN Furgusson .There is plenty of action weather coming up and probably new features will appear each day during this current set up .YOU realy can find interest in other weather synoptic situations with out having raging easterlys every week of every winter .So tonights Models firms up on stormy outlook with cold air gradually being brought in to the mix ,SO CHILL OUT .

[Biggin]

. 

 

Not understanding all the current angst in here either. 

Really?? you love it. PS loving the IF   Shed    love in AFAIK the models past 7 days are struggling

Edited December 17, 2013 by Biggin

[fergieweather]

Latest 4km UKMO products interesting re Thursday. The snow shower story looks really ripe into the NW (pretty prodigious actually) with some further south at times, e.g. Mendips Plateau area; more so Dartmoor. However, the hail signal in 4km PPN type discrimination modelling - irrespective of neutral or warm bias being applied - is even more compelling, especially for western areas south of the Midlands and eastwards where showers penetrate inland. So plenty of hail looks probable. Meanwhile, whatever snow does manage to actually lie into Thursday (e.g., 5-10cm parts of Pennines; to 20+cm parts of upland W Scotland; just a cm or two at most in West Country uplands) is expected to rapidly and entirely thaw (some of highest ground of N/NW excepted) on Saturday.

Edited December 17, 2013 by fergieweather

[nick sussex]

Brilliant POST BY iAN Furgusson .There is plenty of action weather coming up and probably new features will appear each day during this current set up .YOU realy can find interest in other weather synoptic situations with out having raging easterlys every week of every winter .So tonights Models firms up on stormy outlook with cold air gradually being brought in to the mix ,SO CHILL OUT .

I can understand that extremes can be interesting but generally speaking gales  and rain you can have in any month in the UK so it's understandable that for most people who like snow and cold in winter its a bit underwhelming not to say depressing to see the Atlantic in a very angry mood, personally given the choice between the current output and a Euro high with faux cold I'd take the latter.

 

In terms of the coldies departing from here during the current spell, well the hardened crew will continue to look out for some potentially colder weather myself included. I refuse to join in the storm love-in because its deemed as interesting, personally I don't like wind or storms.

 

And without the coldies and "our search for cold" the tumbleweed would be blowing across the thread, fair play to those who find the current output interesting, each to their own. As SSB said you can like cars but not all makes!

[legritter]

I can understand that extremes can be interesting but generally speaking gales  and rain you can have in any month in the UK so it's understandable that for most people who like snow and cold in winter its a bit underwhelming not to say depressing to see the Atlantic in a very angry mood, personally given the choice between the current output and a Euro high with faux cold I'd take the latter.

 

In terms of the coldies departing from here during the current spell, well the hardened crew will continue to look out for some potentially colder weather myself included. I refuse to join in the storm love-in because its deemed as interesting, personally I don't like wind or storms.

 

And without the coldies and "our search for cold" the tumbleweed would be blowing across the thread, fair play to those who find the current output interesting, each to their own. As SSB said you can like cars but not all makes!

just like to add that myself along with many posters am a cold snowy Chap ,hoping for that High to the north with plenty of snow  chances ,but i keep myself happy with other interesting weather .but im not giving up hope ,That Vortex can be broken and who knows whats around the meteorological corner .