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

[Cloud 10]

Far more colder members in today's ECM 00z ensembles which is comforting amongst the chaos of

the NWP operational runs.

 

yesterday..  today..

 

 

Have to say an amazing run from the GEM which certainly retains its Golden Snowflake Award

from yesterday. 

[Downpour]

I think some people are over reacting to that UKMO run. You can see by the final frame that forecasters would face a nightmare in predicting what would fall from the sky. -2/-3 uppers, a front straddled across the country and a whiff of a continental undercut with some frigid uppers not that far out east......says a dumping of snow for somewhere in my book.

It's possible not a bad chart for those of us tucked away in the sheltered SE corner. But too risky IMO, and would give points west a soaking. 

[Cecil Hogmanay Melchett]

How can you make that determination from the H500 charts?, unless you have access to the dew point data, 850hpa, 950hpa data, precipitation data etc..

 

If you have that information, please post it for us.

 

Thanks.

As i said,if im reading it wrong im happy to be corrected but the air over the UK all the way out to 144 looks of Atlantic origin,the 850's are available on meteociel and are generally -4 across the BI at 144 apart from NE Scotland which is around -6.

For my money thats rain for the vast majority.

Unless someone can say otherwise? 

[gottolovethisweather]

For those panicking over individual runs or conversely as per last evening getting over-exuberant with comments such as "its on its way, -20s are on their way, dumpings of snow fortchoming" and the usual shenanigans should take a look at the following images shown by the link provided by Jason earlier. What we are being shown here are the UNCERTAINTIES at ONLY t+108 hours which is output relating to next Monday on this run and it's Thursday now. Look at the SPREAD of UK options, truly anything is possible.

 

http://meteocentre.com/models/get_ensemble.php?lang=en&map=fr&run=00&mod=ncep_geps&stn=PNM&hh=108

 

It would be senseless IMHO to even look beyond this period of uncertainty, yes by all means discuss it but take heed of JHs words from earlier (paying special attention to the last paragraph) shown here http://forum.netweather.tv/topic/78936-model-output-discussion-1st-january-2014-06z-onwards/?p=2890243.

Edited January 9, 2014 by gottolovethisweather

[Cheshire Freeze]

As i said,if im reading it wrong im happy to be corrected but the air over the UK all the way out to 144 looks of Atlantic origin,the 850's are available on meteociel and are generally -4 across the BI at 144 apart from NE Scotland which is around -6.

For my money thats rain for the vast majority.

Unless someone can say otherwise? 

 

-4 uppers with a low level continental drift is more than sufficient to support snowfall. You know this. Would be marginal for sure but a transition to snow would be likely when all said and done

[Cecil Hogmanay Melchett]

-4 uppers with a low level continental drift is more than sufficient to support snowfall. You know this. Would be marginal for sure but a transition to snow would be likely when all said and done

I don't see a continental drift on ukmo,thats the point!!

[chionomaniac]

As i said,if im reading it wrong im happy to be corrected but the air over the UK all the way out to 144 looks of Atlantic origin,the 850's are available on meteociel and are generally -4 across the BI at 144 apart from NE Scotland which is around -6.

For my money thats rain for the vast majority.

Unless someone can say otherwise? 

 

 

-4 uppers with a low level continental drift is more than sufficient to support snowfall. You know this. Would be marginal for sure but a transition to snow would be likely when all said and done

Perhaps you two could carry on this debate by pm and spare the rest of us.

 

The fact is that the UKMO will have changed by the 12Z making this snow /rain debate at T+144 a complete irrelevence!

[BM4PM]

Hello

Correct me if I'm wrong as I'm a bit of a newbie/learner. But shouldn't we be taking the models that have been inconsistent with a pinch of salt (aka ukmo).from what I've seen gem has lead the way on this.

[The PIT]

I wonder UKMO becomes the worst model now it's not playing ball. Got a feeling it maybe the best performing one over the last few days.

[Snowman.]

6z? On phone usually starts rolling out by now.

[Cecil Hogmanay Melchett]

Anyway,gfs06z at 132 should hopefully show the low disrupting and the energy heading south east.Im pretty sure it will look better than UKMo for sure

[Tim Bland]

06z out to mid week and shows zip chance of snow so far.. Fingers crossed for the low to dive SE and drag in the cold uppers lurking to our east

[garbagebags]

6z? On phone usually starts rolling out by now.

Coming out fine on desktop, at +132 now. Showing slightly higher heights to the north thus far. 

[johnholmes]

I wonder UKMO becomes the worst model now it's not playing ball. Got a feeling it maybe the best performing one over the last few days.

 

see statistics for n hemisphere below

http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_acz6.html

[cooling climate]

On a more sobering note with the wave 2 amplification at its greatest over the next week of so

this is probably our best shot at getting a cold spell to take hold but if this goes titicus verticus

then we may not see another chance for a couple of weeks or more.

 

The 06z out to t132 looking good just need the trough to disrupt under the block to stop it sinking

and bingo.

[recklessabandon]

GFS Ensembles still suggesting a lowering of heights in central Europe and the Med from around the 15th, though, there is significant scatter from around that point, which, suggests significant uncertainty still. General pattern still suppports easterly flow off the continent, but the strength of advection and longevity still very uncertain.  Ops runs seem to be sitting in the middle (and on the fence?!).

[weather eater]

HelloCorrect me if I'm wrong as I'm a bit of a newbie/learner. But shouldn't we be taking the models that have been inconsistent with a pinch of salt (aka ukmo).from what I've seen gem has lead the way on this.

Not really, unfortunately it’s not as simple as that, it’s perfectly feasible for a model to be consistent but consistently wrong at the same time.

Edited January 9, 2014 by weather eater

[loafer]

HelloCorrect me if I'm wrong as I'm a bit of a newbie/learner. But shouldn't we be taking the models that have been inconsistent with a pinch of salt (aka ukmo).from what I've seen gem has lead the way on this.

 

At the risk of being a bit profound, an inconsistent model is only inconsistent until the other models join it!

 

The best approach, as the more experienced posters have said, it to stand back from the detail and look at the trends.

[Snowman.]

I wonder UKMO becomes the worst model now it's not playing ball. Got a feeling it maybe the best performing one over the last few days.

Difficult to say, considering all models are flipping and flopping it's going to be difficult to predict.

[Staffordshire]

Hello Correct me if I'm wrong as I'm a bit of a newbie/learner. But shouldn't we be taking the models that have been inconsistent with a pinch of salt (aka ukmo).from what I've seen gem has lead the way on this.

yes that's correct we should, however gem hasn't been 'leading the way' it's just been the most progressive for snow and cold, that dosent mean it is correct and we aren't waiting for the other models to fall in line with that, the weather will do what it wants the models just try and predict what that will be

[tight isobar]

As i said,if im reading it wrong im happy to be corrected but the air over the UK all the way out to 144 looks of Atlantic origin,the 850's are available on meteociel and are generally -4 across the BI at 144 apart from NE Scotland which is around -6.For my money thats rain for the vast majority.Unless someone can say otherwise?

tbh talking about upper gradients 850hpa) at this stage is near on pointless. Let alone precipitation and specifications regarding favoured/unflavoured locations. There's bound be tweaks, and uk snowfall is almost always now cast situ at lower level destinations. Lots to be resolved in all upcoming evolution. Regards

[cooling climate]

t144 and the block is 10mb higher than on the 0z run. so far liking this

run a lot.

[garbagebags]

t144 and the block is 10mb higher than on the 0z run. so far liking this

run a lot.

True but it's quite a bit further east which will mean it will be harder for the cold to reach us (or in reality, simply not reach as far west)

[Cecil Hogmanay Melchett]

t144 and the block is 10mb higher than on the 0z run. so far liking this

run a lot.

Yes-makes much better viewing than the UKMo run.Looks well poised at 144h to drag in those cold uppers across Scandy

[weather eater]

At 144hrs the 06z is much the same as the 00z, spot the difference, over to you Mr Murr.