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

[mcweather]

Some genuinely interesting developments on the models this evening. It will be interesting to see where the ECM run sits within it,s ensemble suite.

GFS has at last smelt the Scandinavian coffee it seems.

UKMO looking good for the transition at 144.

 

It does seem that some sort of change from the current god awful set up is now afoot with the possibility of a battleground scenario being one of the possible options.

As we all know the precise track and position and orientation of fronts a weather systems then comes into play in deciding who gets what.

 

Still way to far out to think about that but if the general pattern proves correct then there could be some interesting times ahead.

[chris55]

The ECM operational run for De Bilt is a mild outlier for that region from next Tuesday!

 

PLUIM_06260_NWT.png

 

 

Thats quite remarkable lol. Maybe the op is overdoing the strength of that diving Low. A weaker Low may well end up providing a colder flow towards Holland....and the UK!

[bluearmy]

looks like the op has overdone that depression and we are more likely to see trough extensions undercutting. the spread on the jet streak late in the run splits energy n and s which is good as we need it to dissipate against the blocking.  overall, an excellent ens run with the spread on 850's keen to bring low uppers (down to -8c) into eastern england. this is the best ecm ens run yet re 850 spreads.  the battleground on those spreads looks further west than the op shows.  trends are good on next week at this point but we are still a long way from widespread snowfall.  however, if you asked me if it can be discounted then the answer is a firm no and we are approaching th point where i might have to share the possibilities with my kids ...............

[nick sussex]

Those ensembles are very exciting news for the long suffering cold and snow lovers here, but we have to be a little bit careful here because in this type of set up you'd expect the operational run with its higher resolution to cope better with trough disruption. However we can just hope that the operational goes with one of those colder members and we can finally say hello to some proper winter weather.

[Matty M]

looks like the op has overdone that depression and we are more likely to see trough extensions undercutting. the spread on the jet streak late in the run splits energy n and s which is good as we need it to dissipate against the blocking.  overall, an excellent ens run with the spread on 850's keen to bring low uppers (down to -8c) into eastern england. this is the best ecm ens run yet re 850 spreads.  the battleground on those spreads looks further west than the op shows.  trends are good on next week at this point but we are still a long way from widespread snowfall.  however, if you asked me if it can be discounted then the answer is a firm no and we are approaching th point where i might have to share the possibilities with my kids ...............

Do not do such a thing until 48 hours! Guaranteed disappointed!  

 

Growing trend this evening, hopefully compounded on the morning output.

[tight isobar]

looks like the op has overdone that depression and we are more likely to see trough extensions undercutting. the spread on the jet streak late in the run splits energy n and s which is good as we need it to dissipate against the blocking.  overall, an excellent ens run with the spread on 850's keen to bring low uppers (down to -8c) into eastern england. this is the best ecm ens run yet re 850 spreads.  the battleground on those spreads looks further west than the op shows.  trends are good on next week at this point but we are still a long way from widespread snowfall.  however, if you asked me if it can be discounted then the answer is a firm no and we are approaching th point where i might have to share the possibilities with my kids ...............

good post the op was weak in feature and I thought it would be a cracker. However ens through up more solid support. And westward correction imo of 850s would be looking a good bet cross mod over coming days....

[Panayiotis]

ECM Mean 850hPa temps from 168hrs to 240hrs:

Looking colder! 

Edited January 7, 2014 by Panayiotis

[tight isobar]

The 50/50 possible fruition of decent cold whether by snap or spell has already gone 60/40 in colder favour. But lets get there firstbefore any talk of ppossible longevity is flagged. ?.

[Duane S.]

Crikey people what do you want, let it develop. We have a rapid change to potential cold pattern appearing. Only 1 week ago we were looking at weeks and weeks of zoneality, indeed winter was over by some even yesterday. The window is being taken, now I'm happy.BFTP

 

If I could of put 2 x likes on this I would have! So true.

 

Those that are already trying to destroy the hopes of coldies either through dreary pessimism or for other reasons only known to themselves. Yes we all know it can go wrong, yes we all know it probably will go wrong but for goodness sake, as BFTP says, give it a chance to develop first before sticking the knives in!? At least wait for it to actually start going wrong and then you can gloat to your hearts content.

 

All to play for, the best opportunity by a country mile for a cold spell all winter. 

[mcweather]

looks like the op has overdone that depression and we are more likely to see trough extensions undercutting. the spread on the jet streak late in the run splits energy n and s which is good as we need it to dissipate against the blocking.  overall, an excellent ens run with the spread on 850's keen to bring low uppers (down to -8c) into eastern england. this is the best ecm ens run yet re 850 spreads.  the battleground on those spreads looks further west than the op shows.  trends are good on next week at this point but we are still a long way from widespread snowfall.  however, if you asked me if it can be discounted then the answer is a firm no and we are approaching th point where i might have to share the possibilities with my kids ...............

 

That's good news on the ensembles BA. I like the sound of trough extensions undercutting or as we call them in my part of the country. A good old Dorset slider!!

 

It really would be good to get a decent block in place in time for the part of winter where the jet tends to lose some of its sting.  In fact I wonder if this what the Met are referring to in a round about way in the last part of he 16-30 day outlook.

[chionomaniac]

looks like the op has overdone that depression and we are more likely to see trough extensions undercutting. the spread on the jet streak late in the run splits energy n and s which is good as we need it to dissipate against the blocking.  overall, an excellent ens run with the spread on 850's keen to bring low uppers (down to -8c) into eastern england. this is the best ecm ens run yet re 850 spreads.  the battleground on those spreads looks further west than the op shows.  trends are good on next week at this point but we are still a long way from widespread snowfall.  however, if you asked me if it can be discounted then the answer is a firm no and we are approaching th point where i might have to share the possibilities with my kids ...............

I think that I may have mentioned this last year, but fundamentally it does not matter how strong a jet streak we see coming out of east America across the Atlantic if there is a split vortex in the way, the jet streak will dissipate and not cross the split.

 

A classic example can be seen on today's 12Z GFS at with the strong jet exiting the US at day 2 and yet it seems to hit an invisible brick wall.

 

 

But that brick wall is not so invisible when we look at the 70hpa charts - we can see the day 4 split vortex that creates the barrier - this will disrupt even the strongest jet streak!

 

 

The GFS has flirted with how long it keeps this split over the last few runs - the longer the better!

Edited January 7, 2014 by chionomaniac

[UV-RAY]

Well we've seen some cracking output this evening but I remain very cautious when anything from the East is forecast, more so when it's a Scandi high as these often fail to push far enough westwards across the UK leaving those out in the West still under an Atlantic regime much like we've seen the past two winters. Leaving the pessimism aside from an IMBY perspective and I'm still more than pleased at what is being offered, in fact I really think we could be in for a stonking February with a trough to our SW and heights to our NE with or without  a SSW event although we will still need too see strong wave activity attacking the PV.

Edited January 7, 2014 by Sceptical Inquirer

[SMU]

So the ensembles have settled us down tonight with the operational the strong outlier at 168

 

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=12

 

of note this eve is the huge swing to cold from the debilt ensembles with the control obvisouly one of our stella runs...

 

I wonder how many of those translate to the UK getting hit as well- I gues 25% at a stab-

Waiting for the weerplaza link to update..

 

the UKMO 144 is similar to ECM but crucially has the low in the atlantic facing INTO our our low moving towards Greenland which will support strong trough disruption -The ECM guides the bowling ball low under with poor allignment.

Also on the ECM ens link the operational is a windy outlier- which is good news as it means the other runs see a shallow low with more undercutting

 

S

PS note the -4c on the ECM ensemble Mean, at 144 & 168- more than enough in an undercutting scenario-

 

IAN ask the senior forecaster to let his hair down tonight & let you post the ECM EPS members for 168!!!!

Edited January 7, 2014 by Steve Murr

[fergieweather]

 

It really would be good to get a decent block in place in time for the part of winter where the jet tends to lose some of its sting.  In fact I wonder if this what the Met are referring to in a round about way in the last part of he 16-30 day outlook.

It's underpinned by interesting signals from recent GloSea5 runs, just to confirm that point, but I might be able to discuss this a bit more shortly (possibly tomorrow) - thanks for patience on that.

[Biggin]

i  know  people  are trying to see the American  weather  come here i cant  see it even  f1  if i am not right i put my hands up but at the moment the only days which we might see some  snow is  jan  17,18, 22  23 at  the  moment  and  that deep f1

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

Isnt our cold coming from the NE /Eastish tho and not from the US ??

[bluearmy]

ironically, the ecm control, whilst frigid for holland with a strong se flow, delivers an initial snow event to the east of the uk before plus zero 850's spread up post day 10. we then get the atlantic blocking spreading across our latitude.

[bluearmy]

 It's underpinned by interesting signals from recent GloSea5 runs, just to confirm that point, but I might be able to discuss this a bit more shortly (possibly tomorrow) - thanks for patience on that.

 

thanks for finally 'spliing the beans' ian.

[Biensie]

 

It's underpinned by interesting signals from recent GloSea5 runs, just to confirm that point, but I might be able to discuss this a bit more shortly (possibly tomorrow) - thanks for patience on that.

Does this mean good news? i have no idea what this means

[Canalboy]

Does this mean good news? i have no idea what this means

Hi Biensie

 

It's a forecasting system used by UKMO (the Met Office one) since 2012 (the latest and greatest purportedly.)  I suspect that it too is picking up on colder options.

[Biensie]

Hi Biensie

 

It's a forecasting system used by UKMO (the Met Office one) since 2012 (the latest and greatest purportedly.)  I suspect that it too is picking up on colder options.

Thanks, Appreciated.  The suspense.....

[mountain shadow]

Check out the direction of travel to the low West of Iceland..

http://cdn.nwstatic.co.uk/gfsimages/gfs.20140107/18/72/h500slp.png

No, not West to East..

http://cdn.nwstatic.co.uk/gfsimages/gfs.20140107/18/90/h500slp.png

East to West.

A good sign for sure.

[Mucka]

Check out the direction of travel to the low West of Iceland..

http://cdn.nwstatic.co.uk/gfsimages/gfs.20140107/18/72/h500slp.png

No, not West to East..

http://cdn.nwstatic.co.uk/gfsimages/gfs.20140107/18/90/h500slp.png

East to West.

A good sign for sure.

 

Yes pressure is higher to the East than the 12z quite early in the run. Looking good in the reliable timeframe anyway and still trending the way we want.

Pressure lower to our South too which will hopefully make undercut easier/more likely.

 

 

Edited January 7, 2014 by Mucka

[Nick F]

The danger though of the potential trough disruption as result of rising heights/blocking to the NE is that the UK ends up under stalling fronts which would bring more significant rainfall - which is not what we want. Really hope the blocking influence pushes further west, than shown by ECM, GFS and UKMO so that the frontal systems stay further west or move south of the UK.  

 

12z GEM offering a drier solution, albeit with wintry showers in the east, with the block building further west and thus significantly colder air reaching our shores from the east too - certainly the best case scenario of the evening.

Edited January 7, 2014 by Nick F

[Panayiotis]

Up to 102hrs on the GFS 18z and its still looking better with the relaxation of heights over Europe compared to the 12z which should allow the low to underut faster and more fluidly...

[shaky]

18z looking even better would you believe it!!