Model Output Discussion - cold spell to end Autumn

[northwestsnow]

I know there is a lot going on in the reliable but i'm not liking the trend on GFS12Z- seems to be wanting to move the PV back to Greenland?

edit shucks thats canada actually !

 

Edited December 5, 2017 by northwestsnow

[snowray]

17 minutes ago, frosty ground said:

 And then back to snow.......

Yes, and some place will be in the honey pot of course with this sort of set up, where it will all stay as snow. UKMO not looking so good, but still all to play for I'd say. The fax charts will be all important from now on.

[warrenb]

Looks like standard winter east to west progression has resumed going by Meto and GFS, you could see it happening in previous runs, with the ridging becoming less pronounced each run.

[northwestsnow]

I'm still watching 12z come out, we really do need to see some kind of heights building to the north- the euro low is helping but unless we get some height rises in scandy or GIN i fear it will all flatten out with the strength of the jet..

[Kentish Snowman in Yorks]

17 minutes ago, terrier said:

I certainly won’t be placing my faith in the gfs with its verification stats. Think ukmo will be nearer the mark. Let’s see what the ecm thinks a little later. But expect it to follow something like the ukmo is showing.

GFS and UKMO would both give your area a sustained spell of snow so you are right in the sweet spot based on those two runs!

[offerman]

Problem

i see

is that Azores high yet again

 

if that could move westwards then that would

open up the floodgates from the north . 

[bluearmy]

Beginning to look more and more like the metoffice predictions (though they have been fairly vague on positioning) 

we need a swing back on 12z ecm and there were clusters from the 00z suite which would offer that.  

GEM keeps us in the game re the size of the envelope although if that cluster dissapears on the eps 12z spread I will be calling that run as too far sw on the envelope 

[igloo]

1 minute ago, northwestsnow said:

I know there is a lot going on in the reliable but i'm not liking the trend on GFS12Z- seems to be wanting to move the PV back to Greenland?

 

as long as we are on the northern side of jet we have a chance of some wintry weather for the next week or so but to be honest the cold uppers are not quite the same as they were some 40-50 years ago so looks mainly the hills above 300m will see some

[tight isobar]

8 minutes ago, northwestsnow said:

I know there is a lot going on in the reliable but i'm not liking the trend on GFS12Z- seems to be wanting to move the PV back to Greenland?

 

Thats 'highly likely' given such close dynamics' and a lot of progression on view...the GFS will look for format/and revert now run 2 run.

Again there is a whole lot of divergance  between-0-144-hrs...

Its all wide open.

And the first slider scenario is as-yet nowhere near a done deal.

Let alone further out!...

Need to be eyeing closer, like for like model 2 model.

The exactions will v-soon start to become clearer now as the models draw things in.

We will soon draw cross agree.

And the developing placements will be much clearer... 

Thank god too!!!

Edited December 5, 2017 by tight isobar

[northwestsnow]

Poor FI from GFS- not seeing any height rises to the north again..

[Chesil View]

Great to see so many members enthused by events over the coming days and to actually have possiblities to talk about after only 5 days of the winter season but i would not be drawing any conclusions regarding sliders etc yet. The envelope of possible tracks is still wide and the Uk is tiny in global terms. It will be friday evening possibly sat morning before we get a final likely steer on the actual track and movement of next weeks systems.

Edited December 5, 2017 by Broadmayne blizzard

[mpkio2]

With regards to 12z UKMO, I do wonder if people realize that both the 0z and 12z are 12 hours apart from each other and show a perfect evolution especially if you put them together...

For example......

0z 05/11 UKMO t24:

12z 05/11 UKMO t24:

0z 05/11 UKMO t48:

12z 05/11 UKMO t48:

0z 05/11 UKMO t72:

12z 05/11 UKMO t72:

0z 05/11 UKMO t96:

12z 05/11 UKMO t96:

0z 05/11 UKMO t120:

12z 05/11 UKMO t120:

0z 05/11 UKMO t144:

12z 05/11 UKMO t144:

The evolution looks a lot better when you put both runs together because each run takes place at a different time of the day on the charts (1:00am for 0z and 13:00 for 12z), so when you piece it all together, it makes much more sense and looks a heck lot better!

The cold (and snow) are very much, still, GAME ON!!

According to what the UKMO says!

Could still change though!

~mpkio2~

Edited December 5, 2017 by mpkio2

[warrenb]

All gone quiet in here hasn't it. Heights just don't get north enough, and when that happens any low coming out of the US will pile through. No matter how deep the trough, with the heights, the lows will just come across us and feed the Euro trough.

[snowray]

UKMO will always be top dog upto T96. At T120 things are 50/50, and at T144, well lets just say I have rarely seen UKMO come close, zonal yes, but with its mild bias it seems to always side with the mildest option. We do after all usually end up with the milder outcome in winter so its hardly surprising that it has this mild bias. 

I have a feeling that UKMO will be way out on this occasion at T120/T144.

Edited December 5, 2017 by snowray

[northwestsnow]

1 minute ago, warrenb said:

All gone quiet in here hasn't it. Heights just don't get north enough, and when that happens any low coming out of the US will pile through. No matter how deep the trough, with the heights, the lows will just come across us and feed the Euro trough.

Chin up Warren, EC 00z op looked really interesting mid term - lets hope for a signal for height rises to the NE gather momentum over the coming day

[warrenb]

Just now, northwestsnow said:

Chin up Warren, EC 00z op looked really interesting mid term - lets hope for a signal for height rises to the NE gather momentum over the coming day

Chin hasn't dropped. The weather does what the weather does. Lived through enough cold winters to not be that worried about it these days.

I suspect ECM will go the same way. Something has changed with the modelling of the PNA which has a large downstream affect.

[Day 10]

I have placed this in the media thread also so please remove mods if you have to. I just thought it was a good read and is relevant right now

https://www.channel4.com/news/by/liam-dutton/blogs/why-you-shouldnt-believe-a-uk-snow-forecast-more-than-three-days-ahead

[karlos1983]

Would be easy and understandable for some to make a reactive post being very downbeat about the 12z output so far, but the short ens haven’t changed, we will see a very potent northerly by the end of the week with snow for many. 

probably best to see at least a couple of more runs to see where things may head after the weekend.

[The PIT]

15 minutes ago, snowray said:

UKMO will always be top dog upto T96. At T120 things are 50/50, and at T144, well lets just say I have rarely seen UKMO come close, zonal yes, but with its mild bias it seems to always side with the mildest option. We do after all usually end up with the milder outcome in winter so its hardly surprising that it has this mild bias. 

I have a feeling that UKMO will be way out on this occasion at T120/T144.

You're behind the times I'm afraid ukmo and ecm constantly outperform the GFS at t144. A few years ago a different story. This doesn't mean the GFS can't be right just less likely so.

[Iceaxecrampon]

37 minutes ago, igloo said:

as long as we are on the northern side of jet we have a chance of some wintry weather for the next week or so but to be honest the cold uppers are not quite the same as they were some 40-50 years ago so looks mainly the hills above 300m will see some

.........for someone living at 302m asl -  that 6ft makes all the difference

Lucky.

[karlos1983]

Still seeing som nice Purbs, P10 for example

[sorepaw1]

Is this just a brief 36hr cool spell for the weekend for Northern Scotland. 

I fail to see anything else sorry

[warrenb]

The deterioration has been happening progressively over the last 24 hours of runs. The -PNA has now been modelled to basically disappear and this has ramifications down the line.

[karlos1983]

3 minutes ago, warrenb said:

The deterioration has been happening progressively over the last 24 hours of runs. The -PNA has now been modelled to basically disappear and this has ramifications down the line.

Disappear might be a bit strong 

Some perspective 

Edited December 5, 2017 by karlos1983

[Craig84]

6 minutes ago, karlos1983 said:

Still seeing som nice Purbs, P10 for example

Yes,12z GEFS still sniffing around height rises to the NE around the 20th..

 

 

 

Edited December 5, 2017 by Craig84