Model Output Discussion - 18z - 6th December onward

[Paul]

To be honest, I've no confidence at all in the EC32; its output changes as frequently as any of the MR models, and I've seen nothing from it which suggests it should be given the respect that Matt Hugo obviously does. Matt must surely recognise, that his summary of said model continually changes, therefore what exactly is that telling us?

I also find it a tad disingenuous for him to suggest '10 out of 10 to the EC32 for predicting the Easterly'. Really? That being the EC32 which flirted with just about every single possible output? Throw enough darts, and one is always likely to hit the board. I cannot believe Matt doesn't notice this, as he's typing his summary out.

Not sure about that, from following the ECM32 for a few weeks now it's actually been very consistent - it's started December with a cold spell (as we've seen), has progged a few milder blips in there (as the med range models are suggesting) but has kept a cool/cold theme generally throughout December. Beyond small detail in terms of timing of milder spells and depth of cold (which you'd expect) there has actually been very little movement in it.

[TEITS]

The T+120 Met Fax produced last evening is, in my view, as close as anyone this far out is likely to be with the surface set up bearing in mind what the models all show at T+120 00z this morning.

Im not sure I agree with that.

This morning we have seen a slight change away from the snow showers set up that the models were indicating with snow showers being less widespread and restricted to eastern coastal counties compared to the Met O forecast.

You also forgot to mention the SW that has appeared in this mornings output and this could prevent a link up between the HP over Iceland and the HP to our NE resulting in a weaker, slacker E,ly flow.

The UKMO Fax charts are usually the best but as I illustrated yesterday they can at times be way off as all model output can be.

Better 06Z though so far.

Edited December 7, 2012 by THE EYE IN THE SKY

[latitude]

Shortwave is less intense on the 6z than 0z, however the cold spell is increadingly being shrunk from both ends.

-5 850 struggling to reach Devon by Tuesday.

[Snowy Easterlies]

looks a better run so far out to 108 high looks stronger

[swfc]

The sw is weaker but pressure is eroding run by run from both sides of the uk.Still looks very complex tho

[Matty M]

-5 850 struggling to reach Devon by Tuesday.

Well the 0z GFS pretty much did away with any easterly.

So the 6z it very likely to be better than that as the 0z OP was an outlier.

However we have definitely moved very far way back in terms of synopitcs.

[Iceberg]

it looks a much better run, Pressure much stronger around greenland, lower pressure over the uk(as it reduces the high lobe), much lesser energy int he short-wave in introduced and better direction.

Have to disagree with the Devon comment, by Monday evening the -5 line is into Devon and N.Cornwall, but not over Southern devon, however it wasnt really there before.

[Nick F]

Yes, the Russian high extending further west towards Greenland, perhaps helped by quicker sinking of the upper/sf low into central Europe.

[MKN]

Its a far better run but the uncertainty surrounding +60 to +96 are quite apparent at the minute and that has a big knock on effect to wether we get cold and snow or cold and frost. The 06z is a step in the right direction regarding the shortwave around Norway that caused the problems on the 00z.

For me until +60 to +96 is sorted you can only hazard a guess at what will come after.

[swfc]

If i was to be on straw clutching mode i would say this isnt a million miles from a decent"compared to recently"run.so close but as the uk weather shows so far !

[Matty M]

And Atlantic fronts arriving by Thursday on this run.

It really did go very very wrong overnight.

[Frosty.]

Did you not bother to read the rest of my post? I followed it on with an explanation. I'll post it again, for your benefit

Yes I apologise, and thanks.

[latitude]

it looks a much better run, Pressure much stronger around greenland, lower pressure over the uk(as it reduces the high lobe), much lesser energy int he short-wave in introduced and better direction.

Have to disagree with the Devon comment, by Monday evening the -5 line is into Devon and N.Cornwall, but not over Southern devon, however it wasnt really there before.

at 132 the -5 line is heading out of Devon. Looks like the breakdown is quicker on this run by Thursday.

Edit: Interesting for SW on Thursday, is the cold air staying put?

Edited December 7, 2012 by latitude

[John Cox]

And Atlantic fronts arriving by Thursday on this run.

It really did go very very wrong overnight.

Hi Matty,

Our Irish Met office this morning don't seem to agree with the GFS:

"During the middle and later part of next week, northeast to north breezes will freshen. This means northern and eastern counties will come under threat of snow showers which may lead to accumulations, even at lower levels. However, the rest of the country will stay mainly dry with clear spells."

[TEITS]

Its a far better run but the uncertainty surrounding +60 to +96 are quite apparent at the minute and that has a big knock on effect to wether we get cold and snow or cold and frost. The 06z is a step in the right direction regarding the shortwave around Norway that caused the problems on the 00z.

For me until +60 to +96 is sorted you can only hazard a guess at what will come after.

Indeed although the more I look at early next week the more I see cold, dry but with lower temps by day/night due to the slacker flow.

I will say to any new members that the +120 fax chart is from last night and the Met O forecasts were produced at 3am. Now in this game 12hrs is an eternity and much can change very quickly.

[matty lfc]

So some are saying "pressure is being eroded from both ends" and others are saying "pressure looks stronger on this run"........are we looking at the same charts???!!!!

It must be an absolute nightmare for newcomers looking into this thread.

[Met4Cast]

Yes I apologise, and thanks.

I apologise too for the blunt reply, I'd just woke up

06z is a slight improvement with high pressure further North. It'll definitely be turning colder next week with snow increasingly a threat, especially in the East. Beyond that is very much up for debate

[chris55]

Snow event edging into the South West, better ridging to the north as well.

[WeatherGuru2012]

-5 850 struggling to reach Devon by Tuesday.

You see this is why i stopped posting on here very often, because people are not reading the charts properly. The -5 850 is over most of the Uk by Monday, nevermind it struggling to reach Devon on Tuesday.

[Thundery wintry showers]

Some of the posts in this thread, like yesterday, are rather over-egging the "downgrades"- looking over the UKMO and ECMWF charts, the consensus there is for a slack east to north-easterly flow with heavy snow showers near eastern coasts, perhaps penetrating a fair way inland at times in association with disturbances and troughs, while the breakdown doesn't come until at least the 16th December and probably later. The GFS for now is rather out on its own suggesting a weak ridge of high pressure followed by a quick breakdown.

[Ian Brown]

Hi Matty,

Our Irish Met office this morning don't seem to agree with the GFS:

"During the middle and later part of next week, northeast to north breezes will freshen. This means northern and eastern counties will come under threat of snow showers which may lead to accumulations, even at lower levels. However, the rest of the country will stay mainly dry with clear spells."

I don't think that is likely to verify John, even if the ECM were to verify it would be pushing it for that to happen for Ireland.

Atlantic makig inroads at T144, now where will it send the energy as block is still in a reasonable position to the North.

[GoonerGregg77]

As far as I'm concerned, the *Hinted* breakdown is in FI. IF there was snowmaggedon forecast for next weekend, it would be downgraded, so there is every chance the *possible* breakdown will in fact be pushed back, and the block gets upgraded, who knows???

I do think from the SW there will be some sort of breakdown/battle scenario, but I do think it's the NE of England Scotland that will do the best out of next week in a BIG way.

The Atlantic will prevail, but in the meantime, were looking at a week of very cold conditions, and the very *REAL* threat of some significant snow.

A failed easterly is not the end of the world. There is a chance this can still turn around.

Edited December 7, 2012 by GoonerGregg77

[latitude]

You see this is why i stopped posting on here very often, because people are not reading the charts properly. The -5 850 is over most of the Uk by Monday, nevermind it struggling to reach Devon on Tuesday.

Really? >

Nearly all SW not under -5 850's.

Edited December 7, 2012 by latitude

[WeatherGuru2012]

So some are saying "pressure is being eroded from both ends" and others are saying "pressure looks stronger on this run"........are we looking at the same charts???!!!!

It must be an absolute nightmare for newcomers looking into this thread.

Its awful isn't it, its becoming a ball ache viewing this thread before looking at the models when I am at work as well. i see all these comments about things downgrading and then why I look people are talking absolute nonsense! At least view the whole run before making comments what don't reflect what the models show

[Nick F]

at 132 the -5 line is heading out of Devon. Looks like the breakdown is quicker on this run by Thursday.

Edit: Interesting for SW on Thursday, is the cold air staying put?

Remember, cold continental SE flow at the surface though, so long as T850s stay sub 0C and temps/DPs are low enough in SE flow, could still stay cold enough for snow if ppn moves in from the SW.

Edited December 7, 2012 by Nick F