Model output discussion pm 13/01/2016

[Harsh Climate]

4 minutes ago, Greenland1080 said:

However wasn't the GFS the first to back away from that arctic Greenland high link up? I've viewed so many charts last 6 weeks my mind is like frazzled bacon.

lol. Yes it was but only in favour of a mild atlantic breakdown. Which is the complete opposite of cold and blocked (which were 90% now likely to have after this weekend.) So in that respect it's going to be completly wrong.

Looking at the UKMO 120 chart

It has consistantly been showing charts like this with no wild swings, it was certainly onto something. Now we have all 3 models heading in this direction (high pressure to the north/northwest with an undercut and colder air to the E/NE trying to move in.

[chicken soup]

GFS definatly back tracking now...but from a snow lovers perspective that could be bad news...surely we want the atlantic to come in a little bit and hit the cold air and produce some snow..cant see snow occuring any other way in this set up...but im more than happy to be proved wrong.

[Yarmy]

From an asbolutely shameless IMBY perspective, does anyone know how good these Arpege high res PPN charts are? 

 

 

 

 

 

Edited January 13, 2016 by Yarmy

[Ali1977]

The GFS may not be the best outcome with regards snow, but definitely good if it's low night time temps you're after. Even down south in some favoured spots we could see -10c or lower over the weekend and early next week, and temps struggling to get to freezing by day. Be nice to get the odd snow shower to assist with that.

The UKMO looks like a snowier end of weekend and early next week, that's not through a breakdown, just from sliding low pressures near by. 

 

[Harsh Climate]

Just now, chicken soup said:

GFS definatly back tracking now...but from a snow lovers perspective that could be bad news...surely we want the atlantic to come in a little bit and hit the cold air and produce some snow..cant see snow occuring any other way in this set up...but im more than happy to be proved wrong.

You make a good point there, If this doesn't happen we could be stuck in middle ground with good cold but unfortanatly no snow.

I can see all the members in the west hoping for a battle between the atlantic and the cold blocked air. This is risky but could be highly rewarding.

Or those like me who live in the east who want a good easterly/northeasterly with snow in the form of snow showers off the north sea

 

[johnholmes]

18 minutes ago, mountain shadow said:

I notice we haven't seem them posted for a good while. I wonder why?

 

Not sure if you are discussing the anomaly charts I use. I post them when it seems my view can add another aspect to the general discussion. To suggest they don't deal with the phrase, 'shortwaves' is to miss the point of their use. They indicate in over 70% of the time, used carefully, the likely upper air pattern 6-14 days in advance. Much as they did this cold spell, 6 days or so before it has happened, and they were solid in suggesting no early end to the cold spell once it started. Only IF the upper air pattern is correctly predicted is there any chance of getting the surface anywhere near correct.

[Snowman.]

4 minutes ago, Yarmy said:

From an asbolutely shameless IMBY perspective, does anyone know how good these Arpege high res PPN charts are? 

 

 

 

 

 

I've heard it's been rated quite highly plus it backed the UKMO. 

[snowblizzard]

1 hour ago, Timmytour said:

T78  The fella in the easy chair over Eastern Europe is moving the chair backwards!!!

Is that towards us or away from us Timmy?

Good or bad?

[lambgregg1977]

Why the charts are showing us these tease frames is annoying. The trend is already set to become less cold next week.

[Ali1977]

I also note from various tweets that the METO have said its not a case of when the Atlantic breaks through, it's "if" it does...So the possibilities of of what could happen next week are open, we may see a cold potentially snowy breakdown, or a high hold the Atlantic at bay. Best case I think we need to see things follow more of the UKMOs idea and get greater heights over Greenland, if we could do that the UK may get a whole lot colder and whiter as time ticks on towards Feb..

ECM will be interesting.

[Snowman.]

4 minutes ago, lambgregg1977 said:

Why the charts are showing us these tease frames is annoying. The trend is already set to become less cold next week.

The trend is quite the opposite. Next week could be the coldest due to the slack air flow over the country meaning many could see -5s down south and -10s up north and some very harsh frosts which I would expect to last all day.

Going to feel incredibly raw.

Edited January 13, 2016 by SN0WM4N

[Midlands Ice Age]

3 minutes ago, lambgregg1977 said:

Why the charts are showing us these tease frames is annoying. The trend is already set to become less cold next week.

Yep currently it showing going  from -10C - -15C, to -2C - -5C.

Good post gregg!

MIA 

Edited January 13, 2016 by Midlands Ice Age

[ALL ABOARD]

3 minutes ago, lambgregg1977 said:

Why the charts are showing us these tease frames is annoying. The trend is already set to become less cold next week.

I dont know what your basing this on? If its the met outlook then just remember this 'cold spell' was only supposed to last two days  

They have to be careful what they write but as fergie's comments earlier have shown they aren't sure 'when' or even 'if' this break down will happen.

 

[mountain shadow]

4 hours ago, johnholmes said:

Not sure if you are discussing the anomaly charts I use. 

No,  I was talking about the 15 day GEFS means that IDO posts which always show a deep PV over Greenland. 

 

[Man With Beard]

43 minutes ago, Harsh Climate said:

UKMO 144h Major undercut and major frontal snow incoming to the west!!

 

 

And snow showers pushing in from the north east.

This is a major head scratch to me. Sure, its cold, but what next? Will the Atlantic fronts get across and link with a Scandi or Euro trough crucial to prolong the cold? At which point? Will the Atlantic fronts have anything left on them by the time they get here? Will the Scandi trough renew its influence? On this chart the UK is bang on the diving line. I'd say 60/40 in favour of at least four more cold days after this, but it could go mild if the different interactions marry up in a particular way.

[lambgregg1977]

Just a disgruntled snow hunter seeing that despite their being uncertainty for next week, the models are UP then DOWN, then UP again, it's exhausting. I don't like the BBC or the Met or indeed follow those forecasts, but just feel as though were all maybe guilty of being too drawn in to these charts as they come around. 

I expect the trend to less cold, and hope all the good work you guys and gals do come to some sort of fruition in terms of a much colder outlook. 

 

[carinthian]

Perfect. This is what I am looking fall. Deeper upper air mass seeping out of Scandinavia with a developing trough heading S. That will maintain the cold block, with increasing the chance of snow showers.

 C

[weather eater]

Not sure we can say the GFS has backtracked to the UKMO so much as gone for another option, very cold and dry. So it has to be said the (I'm Pleasantly surprised) rock solid UKMO would be preferable, it has far better long term prospects and better snow prospects, which is what we want. The GFS looks an eventual sinker with a return to milder SWlys. Good thing is, nothing is nailed on and the evolution has the potential to be better yet.

Edited January 13, 2016 by weather eater

[Rocheydub]

56 minutes ago, Harsh Climate said:

UKMO 144h Major undercut and major frontal snow incoming to the west!!

 

 

And snow showers pushing in from the north east.

That really is a frigid cold pool a gathering up over in Mainland Europe and Scandinavia. If we could tap into that beauty with that Atlantic undercut dragging it our way, these wee islands would get an absolute pasting. Knife edge stuff though. Great model viewing!

[nick sussex]

Well the GFS now has the cold in place well into next week. The UKMO looks snowier if trough disruption is favourable.

Its nice when you have two different solutions at T144hrs that are both cold and not tearing your hair out with one good and one rubbish one!

 

[i luv snow]

21 minutes ago, Midlands Ice Age said:

Yep currently it showing going  from -10C - -15C, to -2C - -5C.

Good post gregg!

MIA 

-10oC to -15oC still being shown on the charts I am looking at. GFS included.

[karlos1983]

8 minutes ago, nick sussex said:

Well the GFS now has the cold in place well into next week. The UKMO looks snowier if trough disruption is favourable.

Its nice when you have two different solutions at T144hrs that are both cold and not tearing your hair out with one good and one rubbish one!

 

It would certainly be nice to have 3 Nick. No dramas please ECM 

 

[Midlands Ice Age]

6 minutes ago, i luv snow said:

-10oC to -15oC still being shown on the charts I am looking at. GFS included.

 

Don't like to tempt fate too much, and I hadn't seen the very end of the GFS run then!  So I went a bit conservative

[nick sussex]

I think if you want chances for snow you're going to have cheer on the UKMO output, the GFS apart from the initial shortwave which might affect the far sw looks dry and very cold.

The UKMO looks likely to try and send some shortwave energy se at T168hrs. Its a bit catch 22 with these set ups because if the block is being underplayed then shortwaves generally end up tracking further south but then you are more likely to stay in the colder conditions.

I think the issue if these shortwaves miss the UK is whether that Scandi troughing can edge sufficiently west to bring some instability into the flow into the UK.

Edited January 13, 2016 by nick sussex

[Daniel*]

Severe frosts in north harsh frosts going S with time, GFS typically puts temperatures on the more toasty side.