Model Output Discussion 1st January 2014-06z onwards.

[Man With Beard]

00Z charts this morning the most interesting for some time. Both UKMO and GFS allow a small wedge of heights to develop close to Iceland around T120/T144. This looks even more promising on UKMO, shame we don't see beyond T144. On GFS, this tiniest area of 500 Hpa heights 'almost' causes the vortex to sink underneath by T192 - a really close one - just needed the prognosis on Euro heights to be slightly weaker. A second attempt in FI hits the bullseye though, classic Icelandic high, floodgates from the east well and truly opened. Maybe this is showing the way out of the PV cycle.

Edited January 3, 2014 by rjbw

[Iceni]

 

Please can someone explain (with graphics) why the jet stream over us is projected to become weaker in the next few weeks at this time of year?

 

It's probably is a simple answer and laughable to the knowledgable but I'm intrigued. The jet stream projections beyond t144 seem to be more erratic than usual these last few weeks….

 

 

Stratosphere warming can reverse the jet stream or at least halt it. Yes? Correct me if I'm wrong... I can't remember the correct term for the phenomenon.

 

PS Where's the Stratosphere Watch thread gone? Got the one  for 2012/13, but not this year's.

Edited January 3, 2014 by Iceni

[That ECM]

http://images.meteociel.fr/im/5063/ECH1-192_sqp3.GIF

This will please many of us modelaholics this morning. Pressure building to our north.

Edited January 3, 2014 by That ECM

[TSNWK]

00Z charts this morning the most interesting for some time. Both UKMO and GFS allow a small wedge of heights to develop close to Iceland around T120/T144. This looks even more promising on UKMO, shame we don't see beyond T144. On GFS, this tiniest area of 500 Hpa heights 'almost' causes the vortex to sink underneath by T192 - a really close one - just needed the prognosis on Euro heights to be slightly weaker. A second attempt in FI hits the bullseye though, classic Icelandic high, floodgates from the east well and truly opened. Maybe this is showing the way out of the PV cycle.

Yep Gfs ends on a pleasing note. This mornings ECM also looks promising around 144, same might argue it looks the best of the big 3 at that time frame, but those pesky European heights scrupper the potential.

[TSNWK]

Ironic really. We get yet another poor EC32 for coldies with signs of start warming having backed off, yet this morning we have decent signs of heights building to our north on the models around 144 and the GFS looks alright in FI.

Cheers

[Captain Shortwave]

The ECM shows the Siberian Express hitting the buffers at the south west coast of Norway, it's edging closer though. Just hope one of the ops from any model at least throws a tease of that air making it to the UK.

[R.P. McMurphy]

Not bad charts this morning for Coldies towards the middle of the Month... This might give a few surprises for some...

 

 

850's Support

 

 

 

 

Snow Risk:

 

 

Ending with a cold NW Feed, snow showers, feeling cold;

 

 

 

So still looking good and ties in with the latest Met Office thoughts for the second half of the month, albeit maybe a few surprises before then !

 

Would post more, but maybe later as I am still half asleep.

 

P.S - Obvious Troll is Obvious Troll... Don't feed it, and it will go away. Ignore

[R.P. McMurphy]

Should have added this....

 

As someone once said...

 

Get Set, It's Coming...

 

 

[IDO]

I must admit when the ECM backtracked on the undercut of the Atlantic ridge because it underplayed a wedge of Scandi heights, I thought our region would miss out on a possible pattern change from the impending lull in the PV.

I have no reason to change those thoughts. The lull, although welcome looks like all it will do is bring higher heights closer to the UK and any trough over the country will be slack for a while, lots of mixing, and the jet will split for several days before more energy spills across the Atlantic for the next part of the zonal train.

We now have to look for another trigger to break the pattern. Possibly the Arctic High, but this has been aimlessly wandering about, with seemingly little purpose. I can see why the EC32 update keeps with the westerly flow and I suspect the ensembles that go cold are the ones benefitting from any further lull in the PV, that are more successful than next weeks forecast.

Not sure we can say either way with regard to help from the strat, as this remains in FI, but it remains our best hope for some cold in February.

Edited January 3, 2014 by i'm dreaming of...

[shedhead]

Once again nothing in the overnight runs to support a pattern change to colder conditions, indeed both the big two remain heavily Atlantic dominated, suggesting mean 

temps will remain on the mild side of average overall.  In the absence of a cold outlook, the main straw to clutch must be the eventual slowing and weakening of the

Atlantic train though, with at least some 'drier, less volatile' conditions in prospect during the latter stages of the run. 

 

Re the ECM32, it appears it has prompted the MO to extend the unsettled conditions through mid month in their latest update, but they maintain the hint of something

potentially colder later in the month.

 

 

GFS

 

 

 

ECM

 

[Frosty.]

Good news for all the coldies from the Gfs 00z op run...if this gfs run was to play out as shown, the first act (between now and middle of next week) could be described as stormy with occasional hill / mountain snow in the north, the second act (second half of next week) calmer with average temps and the third and final act turns wintry...yes the gfs 00z finally brings what I consider to be proper january weather. It's been like a long extension of autumn so far with all the gales and heavy rain but the latest gfs brings all that to a halt and the weather undergoes a complete transformation into cold and blocked conditions with battleground snow scenarios as atlantic lows try but fail to displace an increasingly deep pool of cold air covering the uk...so real winter could be on the way within the next 10-15 days with snow, ice and frost / freezing fog instead of storm force winds and flooding.

Edited January 3, 2014 by Frosty.

[Paul]

The usual reminder - this is the model thread so please use it to discuss the model output and not just to 'report' and add spin to updates from others either in this thread or other sources.

[Timmytour]

 

The ECM shows the Siberian Express hitting the buffers at the south west coast of Norway, it's edging closer though. Just hope one of the ops from any model at least throws a tease of that air making it to the UK.

I seem to recall something similar last winter. Although a notable one, we never got flooded with the deep cold that we seemed to constantly be on the cusp of.This time those buffers seem to be preventing any cold hitting us.But the last few days of december last winter seemed bleak for prospects, and we ended up with a notable one, so all hope is far from lost.We've had a run of cold winters. Typical then that it seems, atm, that run has ended when a politician stuck his toe in the water...." I predict this winter...we’ll probably have a very cold winter " JOHN MAJOR - 22OCT 2013

[nick sussex]

No change this morning, even with the models doing us a favour upstream with the inland runner low over the eastern USA they resolutely refuse to not phase energy from the PV and the troughing over the UK.

Sum total the fish freeze in the Faroes and the UK's cold defences repel any excitement! It's really that simple this morning, the limpet trough just hangs around for what seems a lifetime waiting to elope with its PV lover.

There are no happy medium situations here for coldies because you either get the phase or not, we'll see whether theres any further sw ridging of the high to the north over the next few runs but IMO Flash Gordon is hanging on by his finger tips!

After the phase tragedy we see both the ECM and GFS a bit better in terms of some energy running further south with still some higher pressure in evidence, in view of the recent December it looks better but still not good enough from a cold perspective.

Edited January 3, 2014 by nick sussex

[Polar Maritime]

Much better potential this morning, with the models starting to get a grip on the pattern change to something much colder and wintry. A nice chart to see, let's hope the models maintain this current trend.

 

[nick sussex]

Much better potential this morning, with the models starting to get a grip on the pattern change to something much colder and wintry. A nice chart to see, let's hope the models maintain this current trend.

 

Are you on the same happy pills as Frosty?  Yes nice chart but sadly at T372hrs, show me that at T144hrs and I might be less grumpy this morning!

[R.P. McMurphy]

Are you on the same happy pills as Frosty?  Yes nice chart but sadly at T372hrs, show me that at T144hrs and I might be less grumpy this morning!

 

Lovely chart & deep into FI - but the GFS has been showing something consistent for the second period of January for some time now... It's all about trend spotting...

 

Nothing for coldies to shout about within the next week or two anyways, so can only look to FI i'm afraid.

Edited January 3, 2014 by Glenn W

[Ali1977]

Extreme FI is still 3 days before the big freeze of 47 started.....straw clutching but still possible to have a notable cold spell later in winter...

[Gibby]

Good morning everyone. Here is my website report on the midnight outputs of the NWP for today Friday January 3rd 2013. Transcript lifted from http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm.

 

All models continue to show a powerful storm system close to NW Britain with a windy SW flow with showers across inland UK and severe gales at the coast and a risk of coastal flooding especially in the SW. This pattern continues well into tomorrow before a slow cessation of wind strength is shown but further troughs moving up from the SW tomorrow could enhance rainfall once more with snow possible over Northern hills. On Sunday a brief window of better weather early will evaporate as all models show yet another storm system out to the NW to start next week with renewed severe gales and heavy rain later on Sunday transferring into showers through the start of next week with winds decreasing steadily with time.

 

GFS then shows showers continuing in lighter winds midweek before a drier interlude gets displaced by troughs of low pressure advancing East slowly across the UK with further rain. This sets the tome for a further spell of changeable and sometimes wet period though severe gales are less likely. It could well turn rather colder too with snow becoming a factor across the North at times as winds turn more ESE here with a Jet stream which ends up to the South of the UK.

 

The GFS Ensembles look very ordinary though with little evidence of significant cold in our corner of the world. With rain events scattered about throughout the period the likely trend is for a continuation of Atlantic driven weather though effects from excess wind and rain could lessen with time with some members offering some quieter anticyclonic interludes with some frost.

 

UKMO today shows the period following midweek next week as one of sunshine and showers as Low pressure fills close to the North at the same time as receding away East. Pressure is reluctant to rise significantly over the UK though and it looks only a matter of time before the next Atlantic fronts exiting the West Atlantic make landfall towards the UK by the weekend.

 

GEM today shows Low pressure gradually moving away East out of the UK from midweek taking a lot of the showery rain with it. A quieter colder period is then shown with a frost risk before the Atlantic brings further troughs into the UK from the West by and over next weekend with further rain at times.

 

NAVGEM today shows the best chance of seeing somewhat drier conditions across the South at least later next week as it builds High pressure close to the South and SE with dry and possibly milder air pulled NE. However, it also shows a straddling trough caught up under this higher pressure which if verified would bring further rain which extends to most areas again soon after term of the run as the Atlantic feeds another trough East.

 

ECM continues to look very unsettled with fronts and depression feeding in from the West right up to the end of the UK. There could be a few longer drier phases than of late when it could be rather colder later next week and it will generally be certain to be less windy but any sustained dry weather looks likely to be a scarce commodity with a Low pressure belt again to the North in 10 days time.

 

The ECM 10 Day Mean Chart continues to show quite a flat bias in the pattern with Low pressure over Iceland and High pressure to the South. This shows that the bias of members lies with a continuation of a zonal pattern with winds preferring a Westerly aspect with rain at times for all areas in temperatures that never look particularly cold.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The Jet Stream flow blows for another 5 days or so under it's current shape and form before a disruption looks likely for a time later next week. It is short-lived though and seems to reset to a West to East flow close to the UK again late in the period.

 

In Summary there seems unlikely to be relied upon settled weather over the next few weeks over the UK. Changes in the pattern are trying to occur later next week when pressure rises to the North somewhat but the problem appears that pressure to the South is too high and with an over riding Jet around this the pattern quickly resets to a zonal one once more later in the output. So although there is a window of better and colder weather likely soon after midweek it looks unlikely to move us out of the unsettled spell with further rain at times from the West then taking hold once more. Temperatures for the most part will not be bad considering it's January but it is likely to become somewhat less mild than of late with some snowfall at times possible over Northern high ground. with time.

[Frosty.]

Are you on the same happy pills as Frosty?  Yes nice chart but sadly at T372hrs, show me that at T144hrs and I might be less grumpy this morning!

Nothing to be grumpy about nick, winter is on the way.

[nick sussex]

Lovely chart & deep into FI - but the GFS has been showing something consistent for the second period of January for some time now... It's all about trend spotting...

 

Nothing for coldies to shout about within the next week or two anyways, so can only look to FI i'm afraid.

The GFS lower resolution past T240hrs is IMO an utter waste of time and money, theres a good reason why the ECM doesn't go out that far in terms of its operational, it doesn't want its reputation trashed.

 

If you look at the verification at day ten its rarely much above 0.4, that has dropped from around 0.8 for day 6, using a blunt tool here but add another 4 days on to that so we're looking at basically 0 by the time you get towards the latter part of the lower resolution.

 

With four runs a day the GFS has enough chances to pick a synoptic that looks interesting but will rarely see the light of day, I'd advise people to stick to max T240hrs, at least we can make a comparison between the ECM/GFS and GEM at those timeframes.

 

Theres just too much error at later timeframes to give us a coherent idea of a strong trend.

 

The ensembles may occasionally cluster together past that point but generally there has to be a very strong background signal that even they couldn't miss!

 

The problem for the UK is that small details matter because its often at the periphery of cold a couple of hundred miles globally in terms of modelling isn't a big deal but makes a huge difference on the ground.

[sebastiaan1973]

Latest windpluim de Bilt shows a dominant S-W wind.

Edited January 3, 2014 by sebastiaan1973

[weather eater]

I would say it looks a bit more promising this morning, least wise some hints of jam tomorrow, strawberry only perhaps, certainly nothing exotic, Although then again how often have we seen these types of jam tomorrow FI charts only for them to fall over once we get into high res. It does look like we are going to get some sort of pattern change now, if only because the Atlantic looks like it’s going to run out of steam somewhat, if we are not going to get any serious cold and snow then dry and settled will do me, better than the interminable rain.

Edited January 3, 2014 by weather eater

[snowice]

Are you on the same happy pills as Frosty?  Yes nice chart but sadly at T372hrs, show me that at T144hrs and I might be less grumpy this morning!

 

I agree its way out in FI and we  have seen this a week ago!at least it looks like the pv is slacking after t144.

[shedhead]

Nothing to be grumpy about nick, winter is on the way.

Yep...but maybe not until Dec

Edited January 3, 2014 by shedhead