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

[nick sussex]

Last chance saloon time if we're to salvage any interest out of the next two weeks. Theres a glimmer of hope around the T144hrs timeframe because the models agree on some pressure rises to the ne. It's a race against time though before the upstream pattern flattens out, you need a shortwave cutting under that ridge to the ne and that high over Scandi extending sw before the next bout of Atlantic guff tries to roll eastwards. If you do get the Scandi ridge west and cut off from high pressure over southern Europe as the next low moves in you should be able to get some trough disruption off that. We either get that scenario or basically the ships sailed and we've missed that opportunity.

 

[malc]

3 minutes ago, Seasonality said:

Hi Ali, which perturbation and what time frame please?

All of them and T+24

[Nouska]

17 minutes ago, Ali1977 said:

Even by day 9 the majority of ENS have high pressure ridging back into the UK - could we be about to see a swing back to a dryer cold set up I wonder. 

Infact by day 10 things are really looking up.

I think the parallel run is probably more representative of those members.

Parallel run only available in the archive back to third day of December but good continuity in this blocked scenario for pre Christmas week.

Last four runs with most recent first. GIF for the latest run.

   GIF 06Z  

 

[booferking]

Updated GFS 12z ens.

[Summer Sun]

The start of Christmas week still looks colder

[John Cox]

1 minute ago, Summer Sun said:

The start of Christmas week still looks colder

There is agreement up to 11th December but after that toss a coin

[Frosty.]

Well I see potential from the Gfs 12z after the mild / unsettled spell as high pressure builds in close to the south bringing a gradually more pleasant spell from the south  with the jet stream pushed north with benign conditions eventually returning to most of the uk but particularly the south with an increasing risk of frost and fog patches.

[SLEETY]

2 minutes ago, Summer Sun said:

The start of Christmas week still looks colder

That's better,the minus 10 line is being breached again,we want to see these increase in the coming days 

[I remember Atlantic 252]

1 minute ago, Summer Sun said:

The start of Christmas week still looks colder

not bad pressure, 1020 average, the key really as 850's are pants, 

[karlos1983]

5 minutes ago, booferking said:

Updated GFS 12z ens.

I'd take that! All day long

[Sawel]

14 minutes ago, Ali1977 said:

Yes cherry picked, but this I think is the coldest run this winter season from any Op or ENS.

 

Pretty similar to what happened on DEC 31 1978. 

[carinthian]

9 minutes ago, nick sussex said:

Last chance saloon time if we're to salvage any interest out of the next two weeks. Theres a glimmer of hope around the T144hrs timeframe because the models agree on some pressure rises to the ne. It's a race against time though before the upstream pattern flattens out, you need a shortwave cutting under that ridge to the ne and that high over Scandi extending sw before the next bout of Atlantic guff tries to roll eastwards. If you do get the Scandi ridge west and cut off from high pressure over southern Europe as the next low moves in you should be able to get some trough disruption off that. We either get that scenario or basically the ships sailed and we've missed that opportunity.

 

Yes Nick, I think you are right. A glimmer of hope there on the UKMO 144t chart. Clearly picks up a trough formation over Southern Scandinvia and its alignment would under cut the developing high further to the north. All about getting the jig saw pieces in the right place. We need to see that high over Southern England now sink quickly. Lets see what the ECM chart shows .

 C

[bluearmy]

6 minutes ago, karlos1983 said:

I'd take that! All day long

looks like its the difference from the 00z run so it seems to show a trend to raise anomaly mid atlantic and drop a bit to our east. the models still playing around with amplification and so many variables around the hemisphere to take into account

[chris55]

1 hour ago, fergieweather said:

Notice however how NCEP's parallel 06z suite heads a very different direction, more in keeping with e.g. GloSea's continued - if somewhat less bullish - favouring of the blocky set-up resurrecting after mid-month (a return to blocking also the majority outcome via EPS products using the DECIDER tool run by UKMO).

There remains strong suspicion (and this is an old story) that current GFS remains very prone to going beserk with mobility at longer leads, thus must remain viewed with due caution.

Either way, confidence is of course very low further into the month and we await this evening's EC Monthly update with great interest to see what crossover (if any) it retains with GloSea.

 

EC46 will be the most interesting run of the day.

Also good to here the UKMOs decider tool is more inclined towards a more blocked set up as well.

Hope you can give us a little summary of EC monthly later Ian.

 

Edited December 5, 2016 by chris55

[Frosty.]

13 minutes ago, I remember Atlantic 252 said:

not bad pressure, 1020 average, the key really as 850's are pants, 

At least its a lot drier than last December, let's be thankful for that

[nick sussex]

We need quick separation of the low near the UK and the one over sw Greenland, this will get it further se with the ridge to the north further sw. Come on ECM!

Could be better at T120hrs but the moment of truth is now approaching at T144hrs, we need a shortwave off that upstream troughing to go se.

Edited December 5, 2016 by nick sussex

[knocker]

17 minutes ago, karlos1983 said:

I'd take that! All day long

But that would give you a surface high to the south west of the UK where I suspect we might be heading.

[Frosty.]

2 minutes ago, knocker said:

But that would give you a surface high to the south west of the UK where I suspect we might be heading.

Wouldn't that mean mild air from the azores feeding around the top of the high?

[karlos1983]

4 minutes ago, knocker said:

But that would give you a surface high to the south west of the UK where I suspect we might be heading.

Ok yes, saw it on my phone, and misjudged, you can keep it! 

[knocker]

Just now, Frosty. said:

Wouldn't that mean mild air from the azores feeding around the top of the high?

Not really it would probably be sourced around the southern States area unless we actually ended up in an enclosed HP again so temps would probably be around average or even a little below.

[Frosty.]

Just now, knocker said:

Not really it would probably be sourced around the southern States area unless we actually ended up in an enclosed HP again so temps would probably be around average or even a little below.

Cheers malcolm

[bluearmy]

hello - its a difference chart, not a mean  ????

maybe similar result though!

[Snowman.]

ECM, UKMO and GFS at day 5.

  

as a bonus PARA 6z

ECM is mind ground as ever, GFS too flat UKMO might be overdoing it. 

Edited December 5, 2016 by SN0WM4N

[bluearmy]

ecm 12z is, like the other 12z's, different to the 00z's and shuts the door on a cross polar surprise. note the deepening system mid states at day 6 which is again, different top the previous run and the other 12z output. that may make a difference to the back end of the run

[booferking]

2 minutes ago, bluearmy said:

hello - its a difference chart, not a mean  ????

maybe similar result though!

Yes its difference chart from 12hrs ago.