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

[Frosty.]

11 minutes ago, Snow Grain said:

January is shaping up to start off unsettled with wet and windy weather.  It will turn colder, initially from the northwest, then from the east, which will bring severe frosts and snow.  The snow will effect eastern counties at first.  Areas of snow will spread in from the southwest at times.

Which model is showing that?.I'm intrigued

[carinthian]

2 minutes ago, nick sussex said:

Close but we need to see the high to the east extend a ridge west over the top of the shortwave. The next low upstream is going to deepen now and rush east so the ridge needs to get west to force that more se or at least help disrupt some energy.

Right Nick, but lets be happy with what we see at 144t . Much improved from todays earlier runs.

C

[northwestsnow]

6 minutes ago, Kentish Snowman said:

Not far off an Easterly there?!

Euro high slug salted...;)

[Ravelin]

Even out to t186 the ECM 0z and GFS 18z ain't a million miles apart.....

  

Just the GFS doing it's usual and blowing up the lows to our NW. 

[Man With Beard]

Right, EC46 time ... Yes I know, I was rather critical of it last night but I really want to look at it closely over a period of time - if there's one or two of you also curious then I hope it's of benefit to you too.

The general picture - I'm guessing each week chart refers to a week beginning on a Monday - so for next week, yes, confirmation that the block is predicted to be some way further east than the last EC46 suggested - quite an unusual difference for the shorter timeframe to make

But after that it's another case of "the block fights back". Anomaly strength drops out over time, and it must be emphasised nothing extreme, but that old tendency to push height anomalies back north over the course of the week 3-6 period. Nowhere near enough to gang a cold forecast on. But enough to conclude the EC46 does not see a continual cycle of zonality for weeks on end, and drier than usual weather remains the theme.

Let's revisit in a week or so and see if it's still barking up the same tree. At this stage though, I would put a major health warning on later stages against unrealistically high hopes of seeing a high pressure in exactly where the anomalies appear

[nick sussex]

I don't think the high is going to last, the signal is pretty strong to move that east but it could still help initially by helping to divert the jet more se. You can see here how that earlier timeframe upto T120hrs is crucial because you need some of the energy from that troughing heading se and not more east in the GFS 12hrs run. As soon as you see that shortwave developing at the base of the trough this shows the real struggle initially by the PV to blast the block away.

We have been here before with the GFS 18hrs run and the momentum imploded in the morning but its view is not really that far fetched, however tomorrow we need a westwards correction and the block a bit further north. It would be great if something would go right for a change!

[northwestsnow]

2 minutes ago, Ravelin said:

Even out to t186 the ECM 0z and GFS 18z ain't a million miles apart.....

  

Just the GFS doing it's usual and blowing up the lows to our NW. 

Clearly gfs has backtracked from its earlier horror shows, kind of beautifully highlights the volaitilty at present..

[feb1991blizzard]

2 minutes ago, Man With Beard said:

Right, EC46 time ... Yes I know, I was rather critical of it last night but I really want to look at it closely over a period of time - if there's one or two of you also curious then I hope it's of benefit to you too.

The general picture - I'm guessing each week chart refers to a week beginning on a Monday - so for next week, yes, confirmation that the block is predicted to be some way further east than the last EC46 suggested - quite an unusual difference for the shorter timeframe to make

But after that it's another case of "the block fights back". Anomaly strength drops out over time, and it must be emphasised nothing extreme, but that old tendency to push height anomalies back north over the course of the week 3-6 period. Nowhere near enough to gang a cold forecast on. But enough to conclude the EC46 does not see a continual cycle of zonality for weeks on end, and drier than usual weather remains the theme.

Let's revisit in a week or so and see if it's still barking up the same tree. At this stage though, I would put a major health warning on later stages against unrealistically high hopes of seeing a high pressure in exactly where the anomalies appear

Have you got week 4 please?

 

Week 5 tasty, yes I know it wouldn't translate to anything special as a mean but at that range, a low anom to S and high to NW.....

Edited December 15, 2016 by feb1991blizzard

[Frosty.]

Some of us would see some white stuff later next week according to the Gfs 18z

Edited December 15, 2016 by Frosty.

[bradymk]

Very different day 7 from GFS 18z to 12z. The trough disrupting over the UK and heights much lower over France and Germany in particular. Some snow to even Southern areas next Thursday.  

Models probably struggling with handling the energy up against the block. If we see more energy going south east than has been modelled though, 18z very plausible as Nick says. 

Also, completely seperate point but it was a colder ECM run tonight too than it probably looked, with some snow next Thursday on the ECM for some central areas of UK too.

Edited December 15, 2016 by bradythemole

[Man With Beard]

4 minutes ago, feb1991blizzard said:

Have you got week 4 please?

 

Week 5 tasty, yes I know it wouldn't translate to anything special as a mean but at that range, a low anom to S and high to NW.....

Here. I couldn't show it earlier because of the watershed

Please don't get too excited though because I've seen a few charts at this range where the colours completely swap by week 1!!!

[Man With Beard]

9 minutes ago, Frosty. said:

Some of us would see some white stuff later next week according to the Gfs 18z

Well I'm blowed. the ensembles have been doing this for days and the op wasn't interested. Now the ens have dropped it, the op picks it up!

[Dennis]

OK GFS18 end of dec 

[feb1991blizzard]

3 minutes ago, Man With Beard said:

Here. I couldn't show it earlier because of the watershed

Please don't get too excited though because I've seen a few charts at this range where the colours completely swap by week 1!!!

Be interesting to see strat charts, all this screams a just above mid latt high to me, cold but dry, we need any high higher latitude.

[snowbunting]

Starting to see the polar vortex wind up at the end of these GFS runs. Christmas eve looks stormy (still). To be honest,  would rather see cold zonality spill down from the NW as that gives us more chance of a NLy outbreak here in Scotland. Alot seems to be depending on that strength and placement of that Russian High,

November promising

December dampner

January might be the joker in the pack looking at the change to zonality.

 

[Frosty.]

Looking blocked again after christmas and increasingly cold!

Edited December 15, 2016 by Frosty.

[karlos1983]

9 minutes ago, Dennis said:

OK GFS18 end of dec 

Now THAT has my attention!! The march west!! Nice!

Edited December 15, 2016 by karlos1983

[Boro Snow]

9 minutes ago, Dennis said:

OK GFS18 end of dec 

Can you explain a bit more than just putting charts up please, tell us what you see etc would be good, 

[northwestsnow]

Just now, Boro Snow said:

Can you explain a bit more than just putting charts up please, tell us what you see etc would be good, 

They are surface temps mate, pretty brutal across much of Europe and cold for the UK.

[Dennis]

5 minutes ago, Boro Snow said:

Can you explain a bit more than just putting charts up please, tell us what you see etc would be good, 

You see the 2m low temp expectations and you see the jetstream position 

[Nick F]

I likened the 12z EC det to Joe Barstardi's recent bath-tub theory in action, with cold upper air / low heights in Siberia to start the cold season sloshing into N America then sloshing over to the far N Atlantic toward NW Europe, albeit with the usual maritime modification.

18z GFS op initially starts the cold slosh toward the NW Europe before sloshing back to Greenland and N Canada as ridging rebuilds over Northern Europe. 

Waxing and waning of the GFS/GEFS Northern European +height anomaly in the medium-longer range really doesn't excite me or give me hope for snow in coming weeks I'm afraid, give me the EC bath tub slosh any day.

nice to see the hints of wintry precip even in the south next week on 18z though, but we have to look west for this cold and bear in mind that the models are often too cold from that direction at that range.

Edited December 15, 2016 by Nick F

[Man With Beard]

Back to major confusion on the GEFS at short range. A staggering number of options at T132, mostly down to the behaviour of those low heights in Europe. The op run was very much middle of the road.

[feb1991blizzard]

3 minutes ago, Nick F said:

I likened the 12z EC det to Joe Barstardi's recent bath-tub theory in action, with cold upper air / low heights in Siberia to start the cold season sloshing into N America then sloshing over to the far N Atlantic toward NW Europe, albeit with the usual maritime modification.

18z GFS op initially starts the slosh toward the N Atlantic before sloshing back to Greenland and N Canada as ridging rebuilds over Northern Europe. 

Waxing and waning of the GFS/GEFS Northern European +height anomaly in the medium-longer range really doesn't excite me or give me hope for snow in coming weeks I'm afraid, give the EC bath tub any day.

nice to see the hints of wintry precip even in the south next week on 18z though, but we have to look west for this cold and bear in mind that the models are often too cold from that direction at that range.

I would prefer the high to stay in situ - in E Europe and Russia - precursor to SSW.

[bobbydog]

I know it's in FI but that chart screams 'potato'

[Guest]

2 minutes ago, bobbydog said:

I know it's in FI but that chart screams 'potato'

Potato????