Model Output Discussion - 30th November onwards

[J10]

Wouldn't this type of setup support frost, fog and more of a faux cold at the surface?

 

I personally doubt it because of the mild Tropical Maratime air on SW winds, if we had Easterly winds even with warm uppers, the chances of faux cold, frosts and fog would be far more likely MO.

[bluearmy]

This basically sums it up, in other words a compromise is of no use, to get a decent northerly then we need the ECM to be correct and there is zero margin for error in that output.

Not far from the truth there ian - very small margins on this.would really expect the ecm mean to begin firming up on this now. Otherwise, you do have to worry that at some point the op will begin to look more like ukmo and the cold will be nearer 2 than 4 days. (Note that the 'warm end' to ecm delivers maxes around 4c for england in sunshine.)

[fergieweather]

quoted in comparative analyses, yes, but i was thinking more about it being used ahead of the euro output re the forecasts.

Ah - no, rarely. But happens sometimes. But yes, ECMWF products considered superior. Many at NWS agree.

[Frosty.]

If Carlsberg.............it would be P12 GEFS 12z which I think is the ultimate pinnacle of excellence we could squeeze out of this upcoming cold blast...I have no hesitation in saying this is the best run today. 

[ChartViewer]

Anomaly charts look poor for any sustained mid to hlb...Yes computer generated tonight but doesn't look pretty

 

[bluearmy]

Ah - no, rarely. But happens sometimes. But yes, ECMWF products considered superior. Many at NWS agree.

Ian, I know that mogreps runs at 18km for 48 hours ahead but do you know what the resolution of mogreps-15 is?

Anomaly charts look poor for any sustained mid to hlb...Yes computer generated tonight but doesn't look pretty

 

I did say that 00z naefs was zonal longer term. Doubt the 12z would be much different, looking at the 12z gefs!

[ChartViewer]

Ian, I know that mogreps runs at 18km for 48 hours ahead but do you know what the resolution of mogreps-15 is?I did say that 00z naefs was zonal longer term. Doubt the 12z would be much different, looking at the 12z gefs!

I totally agree ba...everything points to a disappointing mid December whatever chart you look at....unfortunately

Edited November 30, 2013 by ChartViewer

[terrier]

Looking at the longer range output it does look very uninspiring for mid dec. but at least we can all get around for Xmas then hopefully jan feb march we may see something more hopeful

[Captain Shortwave]

ECM ens suggesting a 2 day cold snap (day 6-7), though an extra day in the north.

Day 10 and northern and Eastern Europe looks rather unresolved suggesting some members with a westerly flow and maybe some showing the Russian high backing west.

Edited November 30, 2013 by Captain shortwave

[Cheshire Freeze]

ECM ens suggesting a 2 day cold snap (day 6-7), though an extra day in the north.

Day 10 and northern and Eastern Europe looks rather unresolved suggesting some members with a westerly flow and maybe some showing the Russian high backing west.

 

Looking at the day 10 ensemble mean, I'd say as many as 30% of the ensembles will show an easterly

Edited November 30, 2013 by CreweCold

[ChartViewer]

Looking at the day 10 ensemble mean, I'd say as much as 30% of the ensembles will show an easterly

However we wont experience any Easterly this side of Xmas and deep down we all know it

[bluearmy]

Looking at the day 10 ensemble mean, I'd say as much as 30% of the ensembles will show an easterly

Tbh Crewe, I reckon more. Will see the extended later but is suspect the London extended t maxes will revert more to their clustered continental look later.And cv, whilst the 00z extended ens were less then exciting for coldies, this did go against recent trends so I wouldn't want to make a mid dec call as yet. Edited November 30, 2013 by bluearmy

[Cloud 10]

Its easy to forget that wintry weather will be affecting the far north of the UK as early as Tuesday behind a cold front...

 

   

 

 

...which continues into the weekend if ECM is correct.

 

 

[Cheshire Freeze]

Tbh Crewe, I reckon more. Will see the extended later but is suspect the London extended will revert more to their continental look later.And cv, whilst the 00z extended ens were less then exciting for coldies, this did go against recent trends so I wouldn't want to make a mid dec call as yet.

 

Yes, you're probably right....wanted to temper expectations though!

[bluearmy]

Yes, you're probably right....wanted to temper expectations though!

That 10 day mean is a strong scandi ridge signature. Depends what happens to the blocking near us. Hopefully it gets 'hoovered up' by the developing ridge.

[Cheshire Freeze]

That 10 day mean is a strong scandi ridge signature. Depends what happens to the blocking near us. Hopefully it gets 'hoovered up' by the developing ridge.

 

I'm sure we'll soon find out the clusterings! I think there was 3 or 4 ensembles in the 12z GEFS which ran with the easterly scenario......but then again we all know how seemingly poor the GFS is at picking out an easterly.

[radiohead]

12Z ECM ENS z500 anomaly chart does hint at a cluster of members going for a Scandi high at T240.

[ChartViewer]

Tbh Crewe, I reckon more. Will see the extended later but is suspect the London extended t maxes will revert more to their clustered continental look later.And cv, whilst the 00z extended ens were less then exciting for coldies, this did go against recent trends so I wouldn't want to make a mid dec call as yet.

Accepted BA but come on 95% of signals do not show M/HLB and if that happens mid Dec is going to be zonal to cool...People need to know Mid range for most of UK isn't going to be 2010...I love deep cold snow....However it isn't going to happen in Mid range for much of UK as many want.

[Cheshire Freeze]

Accepted BA but come on 95% of signals do not show M/HLB and if that happens mid Dec is going to be zonal to cool...People need to know Mid range for most of UK isn't going to be 2010...I love deep cold snow....However it isn't going to happen in Mid range for much of UK as many want.

 

That crystal ball of yours going strong then?

[ChartViewer]

That crystal ball of yours going strong then?

No its what the polar vortex strength, gfs, jet, anomaly charts suggest so im going by them

[bobbydog]

I totally agree ba...everything points to a disappointing mid December whatever chart you look at....unfortunately

 

i'd say, everything points to a hit or miss northerly in about a week. after that, everything points to..... anything.....

[Summer Sun]

Tonight's ECM ensemble shifts the coldest 850's away at t192 unlike the Op run

 

 

Ensemble

 

 

After this we have good agreement for less cold air to move in though surface temperatures would still be low and if skies cleared at night we could be looking at minus double digit temperatures especially in rural areas with any snow cover

 

 

The GFS ensemble barely gets the -5 850's into England

 

 

After that less cold air moves in

 

[Joe Levy]

Tonight's ECM ensemble shifts the coldest 850's away at t192 unlike the Op run

 

 

Ensemble

 

 

After this we have good agreement for less cold air to move in though surface temperatures would still be low and if skies cleared at night we could be looking at minus double digit temperatures especially in rural areas with any snow cover

 

 

The GFS ensemble barely gets the -5 850's into England

 

 

After that less cold air moves in

 

With regards to the ECM ensemble, I think it's worth bearing in mind that the shifting of the cold air at 192 will be down to many of the members removing it early, whilst many may continue the cold much later, as is always the case with ensembles. By the way Summer Sun I hope you realise I am not criticising your analysis, I am just drawing attention to the fact that it is only a mean of the ensembles and so must not be taken at face value

[gottolovethisweather]

Its easy to forget that wintry weather will be affecting the far north of the UK as early as Tuesday behind a cold front...

 

ECM0-72.gif    fax72s.gif

 

 

...which continues into the weekend if ECM is correct.

 

Indeed Cloud 10, gottolovethisweather has had his beady eye on the 3rd December timeframe for some time. The short-term outlook has remained unaltered despite folk wanting to slate todays GFS 12z, we must remember the consistency of the ensembles as the mid-range scene is now where the confusion remains, i.e. t+120 hours or thereabouts.

 

Remember that the GFS nailed that front (well not specifically the front) at t+216 hours on the 24th November, check my reference re: the 3rd December date below.

 

http://forum.netweather.tv/topic/78387-south-westcentral-southern-england-regional-weather-discussion-061113-0000z/?p=2844673

 

Even stronger evidence, came about two days later, i.e. where the 3rd December timeframe was at t+168 hours range. 

 

http://forum.netweather.tv/topic/78508-model-output-discussion-18th-nov2013-12z-onwards/?p=2846153

 

 

The above is a good reason for trusting the GEFS ensembles most of the time. Besides, it may have also nailed a whole new trend (hopefully not?) but this will start to unveil itself at the timescale of next Friday onwards.

Edited November 30, 2013 by gottolovethisweather

[ChartViewer]

With regards to the ECM ensemble, I think it's worth bearing in mind that the shifting of the cold air at 192 will be down to many of the members removing it early, whilst many may continue the cold much later, as is always the case with ensembles. By the way Summer Sun I hope you realise I am not criticising your analysis, I am just drawing attention to the fact that it is only a mean of the ensembles and so must not be taken at face value

But have you studied the following

 

10-15 height anomaly - Heights flattened and sunk suggesting zonal

Jet more Zonal west to east

PV Strong

Heights over Europe building

 

I certainly don't want this but it is what is shown.