Model output discussion - 5th December 2016 - Into Winter we go

[karlos1983]

ECM ensembles continue to paint a fairly average picture temp wise. Perhaps just showing signs right towards the end of a split between milder/colder solutions appearing. 

Edited December 16, 2016 by karlos1983

[Man With Beard]

34 minutes ago, karlos1983 said:

ECM ensembles continue to paint a fairly average picture temp wise. Perhaps just showing signs right towards the end of a split between milder/colder solutions appearing. 

ECM mean chart pulls the trough back into the Atlantic between D10 and D15. 

  

but not overwhelming dry if looking at the individual runs

So without seeing more info, a bit of guesswork needed ... probably a split between some runs that keep the Atlantic tracking close enough to the UK, and other runs that rebuild a block to the east - a block with mild SW possibilities and just a few colder runs with a more northerly block.

I was interested to see quite a number of runs going for snow in De Bilt next week. Not too far from the SE of England, of course, but timeframes probably too short now for a large enough correction.

 

[West is Best]

5 hours ago, karlos1983 said:

At the risk of getting mobbed! I'm actually looking forward to some active weather! 

And im sure it wouldn't take long for favoured spots to see some snow should  this verify.

 

I struggle to get excited about cold zonality. However I've been completely wrong about it in the past, and indeed have twice seen snow in north Devon on Christmas Day from such a set up.

We're in for a weather system reboot.

Call this a hunch, and I cannot entirely explain it, but I have a feeling the models may go topsy turvy soon with some signifiant cold runs appearing in the next 3-4 days, including emerging cold in the east. I think it's a hunch partly based on the way the polar vortex is shifting around and cold depths are moving in the north ... mobility is not always a bad thing.

Edited December 16, 2016 by West is Best

[booferking]

1 hour ago, West is Best said:

I struggle to get excited about cold zonality. However I've been completely wrong about it in the past, and indeed have twice seen snow in north Devon on Christmas Day from such a set up.

We're in for a weather system reboot.

Call this a hunch, and I cannot entirely explain it, but I have a feeling the models may go topsy turvy soon with some signifiant cold runs appearing in the next 3-4 days, including emerging cold in the east. I think it's a hunch partly based on the way the polar vortex is shifting around and cold depths are moving in the north ... mobility is not always a bad thing.

Cold zonality is better than nothing and as you say a few people could have a surprise from it, have had quite a few White Christmas from it in the past myself.

Edited December 16, 2016 by booferking

[blizzard81]

12 minutes ago, booferking said:

Cold zonality is better than nothing and as you say a few people good have a surprise from it, have had quite a few White Christmas from it in the past myself.

We need tonight's ecm to revert back to yesterday's 12z run.

[karlos1983]

I'm screwed in that setup living on the costs del Bournemouth, but any change is welcomed by me now. I only ever remember having 1 white Christmas and that was 2010, and it was thawing quick on the big day itself! Apart from one year I spent on Loch Long, and we had a biblical amount of snow xmas eve. That's was fun! But we are talking 20 years ago. I'll take cold zonality from yesterday's 12z ECM. 

Edited December 16, 2016 by karlos1983

[Faronstream]

GFS 06Z on christmas eve looks not that good, we have seen worse in 2007,2013 and 2015 but still too mild and risk of heavy rain. On this chart i will show the small changes we need to see if we want snow around christmas

[northwestsnow]

UKMO-

[Summer Sun]

Quite a rapid development of the low for Christmas

23rd

24th

[radiohead]

A stormy Christmas Day in Scotland on the GEM

[karlos1983]

GFS 12z says snow for South Wales/ south midlands on xmas day! 

Edited December 16, 2016 by karlos1983

[Frosty.]

4 minutes ago, karlos1983 said:

GFS 12z says snow for South Wales/ south midlands on xmas day! 

Indeed it does!

Edited December 16, 2016 by Frosty.

[karlos1983]

1 minute ago, Frosty. said:

Indeed it does!

Bournemouth micro climate doing its thing there 

[NorthernRab]

12 minutes ago, karlos1983 said:

GFS 12z says snow for South Wales/ south midlands on xmas day! 

It looks extremely knife-edge and will require monitoring, but the GFS does show the possibility of quite widespread snow for Scotland in particular, but also interest for South Wales, parts of the midlands and the NW of England. 

 

Edited December 16, 2016 by NorthernRab

[Summer Sun]

Christmas day and Boxing day look very wet according to GEM could well be some flooding around if it comes off

[Northern Sky]

Good consistancy from the GFS, the 6z and 12z look very similar right up to 150 + hrs. I quite like the look of it actually, it would feel cold in the stiff NW wind and even the chance of a few flakes of the white stuff for a few places. At least it will be a change from this current bland weather which is boring me to tears.

[mb018538]

One word for the 12z runs - horrendous

looking more than likely a stormy Xmas is in store for a good chunk of the uk.

[Frosty.]

4 minutes ago, Northern Sky said:

 At least it will be a change from this current bland weather which is boring me to tears.

Well said, I completely agree with you, some action packed weather is on the way according to the models for a change!

Edited December 16, 2016 by Frosty.

[Nick F]

What we are seeing on the 12z GFS op are lobes of  circumpolar trop vortex pushing progressively further south over the N Atlantic toward day 10, which in turn is pushing the polar front jet on an increasingly southerly track. So despite the unsettled zonal outlook, there are bouts of cold zonality behind the surface depressions which could bring some whitestuff, mainly over the hills, over the Xmas period.

I'm personally looking forward to some winter storms rattling the UK  with some wintriness mixed in, as it makes it more interesting for a forecaster to talk about and follow than stagnant anticyclonic gloom. But I'm under no illusions that this spell of zonality will be long-lived. As others have mentioned earlier today, the ensembles have been hinting at retrogression of the trop PV to our NW in the 11-15 day range, so we may well see the high pressure system to the east spread it's influence further west, though it may also join with an extended Azores ridge if we don't get the southerly tracking jet energy to maintain to south of the UK.

[stewfox]

8 minutes ago, mb018538 said:

One word for the 12z runs - horrendous

looking more than likely a stormy Xmas is in store for a good chunk of the uk.

??

Its better then 0z and 6z  as we see whole of UK in sub -5c 850s on 23/12

Obviously not wide spread snow but more lamp post watching required, hardly 'horrendous'

[Frosty.]

Settled weather is very much the form horse to return after the unsettled spell, let's hope when the anticyclonic pattern returns it will herald some proper cold weather early in 2017!

[Iceberg]

Gfs p backs uk the gfs operational nicely with a mixture of sleet/snow/rain for most over the 24/25.  With snow back edge, frontal or showers a possibility for many. 

Meto t144 looks to have plenty of entrenched cold pm air as well. 

I can see Thursday to Boxing Day period being a right pain to forecast. 

[Summer Sun]

After an unsettled spell over Christmas things are shown to slowly settle down as we leave 2016 and move into 2017

[karlos1983]

4 minutes ago, Iceberg said:

Gfs p backs uk the gfs operational nicely with a mixture of sleet/snow/rain for most over the 24/25.  With snow back edge, frontal or showers a possibility for many. 

Meto t144 looks to have plenty of entrenched cold pm air as well. 

I can see Thursday to Boxing Day period being a right pain to forecast. 

Agreed iceberg. Maybe not for my location but l believe a lot of people may get a festive surprise or 2 

as frosty says, anticyclonic weather looks set to return towards new year, hopefully positioned sufficiently far north to bring in the easterly freezer 

[Badgers01]

42 minutes ago, northwestsnow said:

UKMO-

looking at that chart you would think maybe easterly in coming ?