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

[Mucka]

and to top it of another model the jma

its incredible to see such a dramatic change if anything id be inclined to say its the worst ive seen since being a member of net weather.

 

Nah. I remember one not so many years ago where there was cross model support and the ensembles were rock solid with mean around -10 only for all the output to completely flip the next day and that was something like T96 as memory serves. Can't remember the year but these sort of climb downs are quite common. I think we just try to erase them from our memory which is why we fall hard every time. 

 

GFS ensembles continue the theme of less inclined toward a cold spell but still the odd decent run in there.

 

 

So although there has been a bit of a climb down today there is still some hope of seeing something wintry albeit perhaps somewhat delayed and diluted to what we might have hoped yesterday. 

We need some of that old British spirit for now.

Stiff upper lip old bean, there's a good chap.

[IDO]

The GFS op had the AH ridging with the Scandi High at T126: 

 

This blocked the Low from moving SE and it bloated up as it stalled and disrupted close to the UK over a few days and in the interim we lost our blocking high.

 

The GFS control at T126:  

 

No connect between the two highs and the Low moves SE.

 

The control at T150:  

 

Much better, so I would discard the 12z GFS Op at the moment as unlikely.

[Duane S.]

Looking out to the critical midweek period next week, I pulled out the first few GEFS members to see if we have a trend one way or the other and gave up on member 4. This could still go any way, a swing back to the output more akin to what we saw yesterday is just as likely as most of the op output verifying. Keep hold of your toys...

[cooling climate]

After reanalysing the UKMO t144 chart it is definitely better than the GFS at that

range and would offer better chances of colder snowier weather as long as the

low starts to disrupt soon after.

[Snowman31]

Apart from the the westward and eastward corrections would I be right in thinking that the problem is the low pressure not being narrow and elongated but instead a big fat blob?

 

 

Can any of the experienced posters help some of us less experienced ones to identify what we should look for in future runs.

Edited January 9, 2014 by Snowman31

[snowking]

As per the previous couple of posts, the ensembles show exactly why nobody should assume anything is 'nailed' until at least this weekend.

 

The GEFS Panel at +150 sums it up:

 

 

So that would be err...

 

- Scandi High

- Slider w/ SEly flow

- Easterly

- Greenland High

- Massive Positive NAO and a westerly

- Low slap bang across the UK

 

Thats quite a lot of solutions for just 6 days away. And where does the biggest uncertainty lie...

 

 

Oh OK then that would be in the three most crucial areas for our evolution. Thanks for another clear solution GEFS...

 

SK

 

 

Kriss, the gefs are rock solid on the axis and placement of the azores ridge in the west atlantic!

 

Another triumph!

Edited January 9, 2014 by snowking

[Mucka]

Apart from the the westward and eastward corrections would I be right in thinking that the problem is the low pressure no being narrow and elongated but a big fat blob.

 

 

And can any of the experienced posters help some of us less experienced ones to identify what we should look for in future runs.

 

You want to see the low pressure disrupt SE. So to look for that you want to see the low being "stretched with a NW/SE tilt as below,

 

 

The more disruption the more energy will get under the block and the further West the pattern will be because the low is not shunting the high Eastward as it will as one "blob" of energy.

Edited January 9, 2014 by Mucka

[tight isobar]

As per the previous couple of posts, the ensembles show exactly why nobody should assume anything is 'nailed' until at least this weekend.

 

The GEFS Panel at +150 sums it up:

 

Screen Shot 2014-01-09 at 17.23.31.png

 

So that would be err...

 

- Scandi High

- Slider w/ SEly flow

- Easterly

- Greenland High

- Massive Positive NAO and a westerly

- Low slap bang across the UK

 

Thats quite a lot of solutions for just 6 days away. And where does the biggest uncertainty lie...

 

 

Oh OK then that would be in the three most crucial areas for our evolution. Thanks for another clear solution GEFS...

 

SK

yes a mass of possible solutions and we are no further forward as to what MAYBE plenty of options yet await.

[Man With Beard]

As per the previous couple of posts, the ensembles show exactly why nobody should assume anything is 'nailed' until at least this weekend.

 

The GEFS Panel at +150 sums it up:

 

Screen Shot 2014-01-09 at 17.23.31.png

 

So that would be err...

 

- Scandi High

- Slider w/ SEly flow

- Easterly

- Greenland High

- Massive Positive NAO and a westerly

- Low slap bang across the UK

 

Thats quite a lot of solutions for just 6 days away. And where does the biggest uncertainty lie...

 

 

Oh OK then that would be in the three most crucial areas for our evolution. Thanks for another clear solution GEFS...

 

SK

Yes an utter lottery and some of the runs are sensational for cold/snow!

[Downpour]

The GFS op had the AH ridging with the Scandi High at T126: gfs-0-126.png

 

This blocked the Low from moving SE and it bloated up as it stalled and disrupted close to the UK over a few days and in the interim we lost our blocking high.

 

The GFS control at T126:  gens-0-1-126 (1).png

 

No connect between the two highs and the Low moves SE.

 

The control at T150:  gens-0-1-150.png

 

Much better, so I would discard the 12z GFS Op at the moment as unlikely.

Agreed. I would prepared to wager that the 12z Op does not verify. As you say, a highly unlikely evolution. Sometimes I simply cannot grasp how GFS produces such warped prognoses. 

[Downpour]

Looking out to the critical midweek period next week, I pulled out the first few GEFS members to see if we have a trend one way or the other and gave up on member 4. This could still go any way, a swing back to the output more akin to what we saw yesterday is just as likely as most of the op output verifying. Keep hold of your toys...

gens-0-1-150.png

gens-1-1-150.png

gens-2-1-150.png

gens-3-1-150.png

gens-4-1-150.png

Some serious scatter there. I think the old phrase the "GFS is struggling" comes into play here. That's not cold bias – just an observation on how erratic this model has been of late. Anyone remember the near-hurricane it modelled the other day which would have wiped the UK off the map? Dr Evil was at the controls, as he often seems to be. 

[Bobby]

Meteociel have added NMM for all Europe now, cooool

 

http://www.meteociel.fr/modeles/wrfnmm.php?ech=3&mode=16&map=20

[Kentish Snowman in Yorks]

I don't know if its just me but some of the output at the moment, particularly today's 12z runs, seem to be quite typical of those kind of set ups that have given the UK copious amounts of snowfall in recent years.

 

Rather than cold screaming easterlys or huge freezing blocks, we are getting coldish setups (cold enough for snow) but with 

 

low pressure never far away.

 

 

 

 

Certainly in recent years, I have found myself looking West on a radar for where my snow is coming from rather than East.

 

 

Eyes down for ECM but I have a gut feeling that next week will bring a few snowy surprises even if there is no Easterly or deep cold...

Edited January 9, 2014 by Kentish Snowman

[bluearmy]

Kriss, the gefs are rock solid on the axis and placement of the azores ridge in the west atlantic!

[Hotspur62]

Think the UKMO has potential at t144 just a shame that as others have said we can't see the 168.This time yesterday everything looked good for cold spell/snap with pretty much cross model agreement.Today,GFS looks horrible for cold,GEM not as good as yesterday so we await ECM.THis reminds me of DEC 2012,just hope that scenario doesn't evolve!!Still all to play for and coldies stay positive!!

[Long haul to mild]

The Golden rule of model watching is, whatever the models are showing at 72hrs plus is going to change and when we we are talking 120hrs plus they are going to change substantially. If you follow that rule you shouldn’t get surprised or disappointed when cold runs go to pot and you shouldn’t get bullish about them verifying either. If you apply those rules to today’s 12z GFS output, then whatever the synoptics being modelling are at 132hrs, those synoptics are going change over the next few days, they may be poorer, they may be better but they will be different. The Low pressure system being modelled to our west at 132hrs which was elongated in earlier runs allowing it to undercut in the way we want is now rather round, not good, but the likelihood is that its shape and track will continue to evolve over the next few days, give me pragmatism over optimism or pessimism any day of the week.

Some of the more dramatic posters would be well advised to take note of the above. The shape of an LP is very hard to model at mid range, and small changes early on have large scale consequences down the line.After all, this is just one set of runs; there are stIll many more to come before next week is properly nailed down. And who's to say that later in January may not be the better bet anyway? There have been a few long range signals suggesting that is the case. Still plenty of winter to go.When you consider the widespread euphoria in this thread only a day or so ago, and the bitter disappointment currently resonating through it, it goes to show how quickly things can change. Who's to say cold fans may not be celebrating in the morning or this time tomorrow? Time will tell as always. Edited January 9, 2014 by Chalk Serpent

[Summer Sun]

Michael Fish is talking about wintry showers later next week in his weekly forecast with possibility of easterly winds

 

http://vimeo.com/83767876

[Tim Bland]

12z GFS ensembles are actually better than yesterday's . 14 out of 23 GEFS members have snow conducive upper air over se eng 17th Jan. (yesterday it was 12). hope remains

[Downpour]

I don't know if its just me but some of the output at the moment, particularly today's 12z runs, seem to be quite typical of those kind of set ups that have given the UK copious amounts of snowfall in recent years.

 

Rather than cold screaming easterlys or huge freezing blocks, we are getting coldish setups (cold enough for snow) but with 

 

low pressure never far away.

 

 

 

 

Certainly in recent years, I have found myself looking West on a radar for where my snow is coming from rather than East.

 

 

Eyes down for ECM but I have a gut feeling that next week will bring a few snowy surprises even if there is no Easterly or deep cold...

You would be more confident of that in your location, here in the east. The trouble is such setups often given snow for the east and buckets of rain for the west, in exactly the part of the country that doesn't need it. 

[Mucka]

GFS 12z ensembles not a pretty sight

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=286&y=128

[Summer Sun]

To my completely untrained eye, the one thing that IS needed but not showing is dry weather.

 

The London ensemble actually doesn't look too bad certainly less rain than we've had over the past month or so

 

 

There is even a %25 chance of snow on the 17th

[Downpour]

GFS 12z ensembles not a pretty sight

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=286&y=128

I may be reading those wrong, but looks as if the Op was on the mild side of the suite. 

[Captain Shortwave]

Not much in the GFS ens, though to have any more confidence than previously would seem a little foolish.

Best run I could find was pet 8 which actually shows something akin the evolution of the March cold spell with heights rising close to Greenland and a wall of cold dense air surging south west along with a low sliding into France.

GEM still looks the best bet, the GFS op is pretty dire and the UKMO offers hope later on, but to be frank, I don't think many could take much more of this.

[Kentish Snowman in Yorks]

GFS 12z ensembles not a pretty sight

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=286&y=128

 

Op and Control both on the mild side of things for a fair chunk of the run though.

 

It is a very complex pattern the models are trying to resolve.  Plenty of time for upgrades and downgrades yet.

[Summer Sun]

I may be reading those wrong, but looks as if the Op was on the mild side of the suite. 

Your spot on