Model Output Discussion - 8th December Onwards

[nick sussex]

I wish these models would just make up their mind!

Unfortunately the 12hrs at least for snow potential this week revert to their scrooge like status of yesterday evening. Too much phasing goes on with energy to the ne of the UK which pulls the pattern east rather than se.

I don't think its as clear cut though for northern areas, theres still a chance of some snow. Thereafter the Russian block sits waiting to redeem its battered reputation.

I think the key thing if its going to stay is that it remains far enough north to exert some pressure on troughing near the UK, if the PV relocates totally to Siberia then as the energy to feed the limpet trough recedes there is a chance to see a ridge extend from the east over the top.

[IDO]

We have not seen the short ensembles that close to the mean for sometime:

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=12&ville=Londres&runpara=0

A cold few days, relatively quick breakdown and then back into a cool setup. Most of the members and the control run look like a zonal pattern where as the op goes with a static pattern.

The GEFS mean at T180 is similar to the 06z:

Atlantic low in charge with the high too far to our east.

A huge Siberian high by T240 (mean):

By T300 still a zonal flow but cool in the south and cold spells for Scotland. The PV not making it to Siberia because of the high, and hence the westerly flow.

T336:

[EML Network]

We have not seen the short ensembles that close to the mean for sometime:

http://modeles.meteo...ndres&runpara=0

A cold few days, relatively quick breakdown and then back into a cool setup. Most of the members and the control run look like a zonal pattern where as the op goes with a static pattern.

The GEFS mean at T180 is similar to the 06z:

http://modeles.meteo...21-1-180.png?12

Atlantic low in charge with the high too far to our east.

A huge Siberian high by T240 (mean):

http://modeles.meteo...21-1-240.png?12

By T300 still a zonal flow but cool in the south and cold spells for Scotland. The PV not making it to Siberia because of the high, and hence the westerly flow.

T336:

http://modeles.meteo...21-1-336.png?12

What are the chances of the Polar Vortex sliding along the length of that high and ending up closer to Scandinavia I wonder ??

Wouldn't that then force a more Northerly outbreak in time for the new year possibly ?

[stainesbloke]

Sometimes we see very stubborn blocking systems and indeed many times they can be a hindrance. This coming block as no intentions of moving very far and this will see the Atlantic get held, and it looks like over or close to us. This really sets us up for a potential soaking, and probably some pretty stormy weather too. The real cold is not going to get a chance to move over us and thus any snow will be shortlived, indeed I suspect most of us won't get any. It'll be and feel cold yes...

Where do we go from here, well there's RJS thoughts, MetO thoughts, maybe a sobering and realistic thought. GP suggested too that the tank will need refuelling as the first spillage of serious cold will take time to replenish from the north before another surge......well the deep cold isn't looking like even reaching us so I think we got some waiting to do.

BFTP

Don't necessarily agree, the cold stays close to our east on the runs so any low pressure moving further south than expected could allow the cold in. I don't think we will know til Wednesday!

[snowmadchrisuk]

Hi, Just a quickie before I hit the pub , but I'm a little confused by the posts saying there is now more chance of the Cold lasting longer and more chance of a Snowy breakdown ... If were talking about next week I don't see it , charts like the one below for next Thursday won't bring much Snow , or are we talking about the FI outlier Cold spell.... That is unlikely to be modeled correctly at this stage , although I do believe there is a chance of going back Cold around Christmas week , that is not based on the model runs...

[Damp and dreary]

I can't see where the slight upgrades are.

If we take the 12z output so far (UKMO and GFS) up to 144 hours compared to the 0z, then we have a faster breakdown of the cold spell and less chance of snow.

All and all a step in the wrong direction so far.

Karyo

But we should not be comparing separate model runs, as said soo many times before (which im sure you will know) compare this 12z with the last 12z run, the same with the 0z etc.

[karyo]

I wish these models would just make up their mind!

Unfortunately the 12hrs at least for snow potential this week revert to their scrooge like status of yesterday evening. Too much phasing goes on with energy to the ne of the UK which pulls the pattern east rather than se.

I don't think its as clear cut though for northern areas, theres still a chance of some snow. Thereafter the Russian block sits waiting to redeem its battered reputation.

I think the key thing if its going to stay is that it remains far enough north to exert some pressure on troughing near the UK, if the PV relocates totally to Siberia then as the energy to feed the limpet trough recedes there is a chance to see a ridge extend from the east over the top.

Nick, what do you think about the 12z UKMO 144 hours?

It looks rather unappealing to me with the Russian high looking like moving south than west.

Karyo

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012120912/ECM1-48.GIF?09-0

ECM @48 tilted quite a bit further south than the GFS

S

[BLAST FROM THE PAST]

Don't necessarily agree, the cold stays close to our east on the runs so any low pressure moving further south than expected could allow the cold in. I don't think we will know til Wednesday!

Indeed but we are now looking for the unexpected....but they the models and this back track has shown how poor they can be.BFTP

[Polar Maritime]

Winter is ticking away. Looks like December has gone. Who kept saying 13 weeks left yet?? Or trends... The models to me show and look like a typical autumnal/winter pattern. With the low sitting to our west producing bands of rain after bands of rain with average temps. As usual cold to the east and a mild west. Really frustrates me with our latitude and lack of cold/snow .... as with most on here. Even paul Hudson is frustrated now after his lil ramp.

I would not call 9 days into December as gone. It's just starting now!

[Col Berkshire]

My god, so much doom and gloom in here. The weather will do what it will do, the models are clearly struggling. We just need to watch it unfold and be thankful we're not in the same position as last year. Many twists and turns to come guys :-)

[Adam lufc]

LOL....

Not really. I do not see anything right now. Hope the charts show cold/ snow but believe me you, this December Is looking like little! We had such a great opportunity and then the models dropped it.

[Frosty.]

Don't necessarily agree, the cold stays close to our east on the runs so any low pressure moving further south than expected could allow the cold in. I don't think we will know til Wednesday!

Agreed, all we currently know for sure is the first half of the week will be cold with widespread frosts and freezing fog, and with some snow showers to n/e coasts on tues/wed. The second half of the week is still unclear but there is more hope of a battleground forming as fronts move north and east into the cold block over the uk, rather than a progressive outcome, I think it will slow to a crawl and dump a lot of snow in parts of the north and east at least..after midweek.

[chris55]

Better heights towards Iceland than the 00z from ECM, will this force the Atlantic just that little bit south?

[nick sussex]

Nick, what do you think about the 12z UKMO 144 hours?

It looks rather unappealing to me with the Russian high looking like moving south than west.

Karyo

It will probably change by the morning! lol

I think the UKMO is developing a shortwave on the southern end of the trough and the jump from 120 to 144hrs shows that this could help pull the troughing nw as it runs east, perhaps allowing a gap for the ridge to extend a bit more nw towards Scandi.

Lets see what the ECM comes out with, maybe that will show something a bit more favourable.

[karyo]

Thankfully, the ECM is better than the other 2 models with the angle of Atlantic attack favourable for breakdown snow!

http://www.meteociel.fr/modeles/ecmwf.php?ech=96&mode=1&map=0&archive=0

It will still turn mild after that though.

Karyo

[Cloud 10]

The 12z gfs and ecm at 96 hrs.

ecm.. gfs..

[YorkshireLiving]

Winter is ticking away. Looks like December has gone. Who kept saying 13 weeks left yet?? Or trends... The models to me show and look like a typical autumnal/winter pattern. With the low sitting to our west producing bands of rain after bands of rain with average temps. As usual cold to the east and a mild west. Really frustrates me with our latitude and lack of cold/snow .... as with most on here. Even paul Hudson is frustrated now after his lil ramp.

Winter has only just begun. It will take one or two cold incursions before we have cold that will produce snow for most, the signals are there the cold will come do not give up hope. Keep watching the models it may need to reload a couple of times before cold sets in.

[TEITS]

Epic chart for Scotland.

Note the positioning of the Russian high between frames +96 & +120.

[Zenarcher]

ECM has made the Atlantic low weaker and because of the stronger heights over our North this has also pushed the low further South,

Yesterday 14th

Today 14th

[The Northern Ramper]

Doesn't the 12z gfs have an eastern bias?

[cooling climate]

After seeing the ECM out to t120 I think this is anything but a done deal yet.

A bit of tweaking (the in word at the moment) here and there and we would keep

the cold and get the snow.

[chris55]

Is the snowy breakdown all over? Is the super undercut (with us on the cold side) a possibility? Who knows. There's about 650 miles in it!!!

Edited December 9, 2012 by chris55

[MR EXTREMES]

looking like the ecm wants to build height over greeland at t120

[MR EXTREMES]

Is the snowy breakdown all over? Is the super undercut (with us on the cold side) a possibility? Who knows. There's about 650 miles in it!!!

agreed i dont think the ecm is eye candy with in the realiable timeframe!!!!

but if pressure continues to build over greenland its a reload but as chino said in the strat thread from the north.

although i think cold and snowy weather is certainly a option in scotland maybe slightly futher south in future runs but northern england southwards does look like being rather cold and wet and very windy.