Model Output Discussion 29th December - Into mid-Winter.

[Mucka]

Just now, frosty ground said:

just a slider instead.

I wouldn't call that a slider. 

It could bring some transient snow turning to rain as the front moves into the cold air though.

[karyo]

The 6z GFS at least has a slightly mnore amplified pattern for Thursday-Friday and slightly colder uppers.

The 0z has a significant mild sector coming down from the northewest on Fri morning.

[frosty ground]

Just now, Mucka said:

I wouldn't call that a slider. 

It could bring some transient snow turning to rain as the front moves into the cold air though.

Some Energy heads south East, Unfortunately the system is just to far east.

The GFS is still moving towards the consensus, as are the other models so i would expect a western correction.

[Weathizard]

Still massive differences between then GFS and ECM at 120, one is going to be left with egg on its face.

[Mucka]

5 minutes ago, Weathizard said:

Still massive differences between then GFS and ECM at 120, one is going to be left with egg on its face.

06z is actually flatter than the 00z from 120 and that was flat.  Ensembles will be interesting.

Edited January 9, 2017 by Mucka

[Stravaiger]

To my untrained eye, the end of the 0Z ECM isn't as bad as the output has been for much of the winter. Yes, we still have heights over Europe, but with a low in the eastern Med. and some lower heights heading towards the Azores the situation has some more promise to it. Certainly if you advect the situation on by 12 hours then a shot of Pm air would be bringing snow to fairly low levels in NW parts of the UK and Scotland esp. 

 

[Rocheydub]

Has anybody else noticed the incorrect use of terminology being bandied anoutbhere of late? My particular bug is the term slider. Not everybody, but some people have been calling low pressure systems sliders, even when they're not sliding anywhere!!! 

It bugs me because it makes me doubt what charts I'd just being looking by at!

As per the recent 00z and the now 06z runs, longevity of the cold looks reduced, but nothing set in stone yet. I always maintain that until you see agreement between the top 4 at 96 hours, nothing is nailed... and at 96 hours there's still a lot to be resolved. Historically, each of the main models will predict HLB and MLB's with difficulty beyond 96/120, as it's not the standard for our locality.

I'll be making a call on the outcome after the 12z's this evening.

[Weathizard]

6 minutes ago, Mucka said:

06z is actually flatter than the 00z and that was flat.  Ensembles will be interesting.

Indeed. UKMO 0z solution appears to be more amplified than the GFS but re: energy around southern Greenland its more in line with the GFS so not sure what to make of that,

 

So esentially same same problem as yesterday: one very amplified, one in the middle and one completely flat as a pancake 

Edited January 9, 2017 by Weathizard

[Stravaiger]

On the subject of Euro heights (and apologies mods if this is inappropriate for this thread, it's just a good way to access some of the most experienced members of the forum) can anyone explain to me why they have become so much more persistent and prominent in the winter months of late? 4 slow starts to the season in the Alps due to strong areas of high pressure that refuse to budge...why?

Is it climate change? What is consistently forcing this new pattern to emerge and so consistently.

Any answers or suggestions welcome.

Cheers!

[frosty ground]

6 minutes ago, Rocheydub said:

Has anybody else noticed the incorrect use of terminology being bandied anoutbhere of late? My particular bug is the term slider. Not everybody, but some people have been calling low pressure systems sliders, even when they're not sliding anywhere!!! 

It bugs me because it makes me doubt what charts I'd just being looking by at!

As per the recent 00z and the now 06z runs, longevity of the cold looks reduced, but nothing set in stone yet. I always maintain that until you see agreement between the top 4 at 96 hours, nothing is nailed... and at 96 hours there's still a lot to be resolved. Historically, each of the main models will predict HLB and MLB's with difficulty beyond 96/120, as it's not the standard for our locality.

I'll be making a call on the outcome after the 12z's this evening.

Well the Low that forms and splits heads south east, It slides....... 

[alexisj9]

10 minutes ago, Rocheydub said:

Has anybody else noticed the incorrect use of terminology being bandied anoutbhere of late? My particular bug is the term slider. Not everybody, but some people have been calling low pressure systems sliders, even when they're not sliding anywhere!!! 

It bugs me because it makes me doubt what charts I'd just being looking by at!

As per the recent 00z and the now 06z runs, longevity of the cold looks reduced, but nothing set in stone yet. I always maintain that until you see agreement between the top 4 at 96 hours, nothing is nailed... and at 96 hours there's still a lot to be resolved. Historically, each of the main models will predict HLB and MLB's with difficulty beyond 96/120, as it's not the standard for our locality.

I'll be making a call on the outcome after the 12z's this evening.

Sliders slid down the east side of a block, a low pressure heading south on the outside of another low pressure is not a slider. It's just a low heading south. Personally I don't mind though, both can produce snow in the right circumstances, it's just I don't think the 6z is on of those, just to warm.

[Rocheydub]

3 minutes ago, alexisj9 said:

Sliders slid down the east side of a block, a low pressure heading south on the outside of another low pressure is not a slider. It's just a low heading south. Personally I don't mind though, both can produce snow in the right circumstances, it's just I don't think the 6z is on of those, just to warm.

Actually, sliders are those low pressure systems that slide any way around, under or over any block... Just for clarification!

[Mucka]

6 minutes ago, alexisj9 said:

Sliders slid down the east side of a block, a low pressure heading south on the outside of another low pressure is not a slider. It's just a low heading south. Personally I don't mind though, both can produce snow in the right circumstances, it's just I don't think the 6z is on of those, just to warm.

Yes it's too warm because it doesn't slide. It actually moves pretty much E/SE in the flow from Ireland to Holland. 

In theory it could develop and move more Southerly and become a trigger low for a ridge behind like this mornings 00z control.

Edited January 9, 2017 by Mucka

[booferking]

And back to what the models are showing ECM looks great for large parts of the country. Snow could fall anywhere over the the 4 day charts below something that we have not seen this Winter.

[frosty ground]

1 minute ago, Rocheydub said:

Actually, sliders are those low pressure systems that slide any way around, under or over any block... Just for clarification!

Do you have a link for this? 

[Mucka]

2 minutes ago, Rocheydub said:

Actually, sliders are those low pressure systems that slide any way around, under or over any block... Just for clarification!

Not how I would describe a slider personally. The clue is in the terminology. A slider slides down a ridge, pretty much N to S.

[MR EXTREMES]

25 minutes ago, Mucka said:

06z is actually flatter than the 00z from 120 and that was flat.  Ensembles will be interesting.

The flat pattern was there this morning and yesterday it's not surprising at all.

It's messy as the gfs normally is.

but truth is its as tetis suggested it's down to now casting.

[Rocheydub]

1 minute ago, Mucka said:

Not how I would describe a slider personally. The clue is in the terminology. A slider slides down a ridge, pretty much N to S.

'That ECM' was described quite widely as a slider too... where the block over Scandinavia had a low pressure system slide underneath it. I stand over my posts

Anyway, this is just pedantic at this stage.

[Gael_Force]

7 minutes ago, frosty ground said:

Do you have a link for this? 

I doubt the term will appear in any scientific glossary.

[Dennis]

dont forget to focus 

[bluearmy]

Dave - I'm a little confused about the disappearance of an easterly. When did the ens/anomolies ever predict an easterly ?

Yes they got the northerly wrong for the weekend just passed (and we can see where that cold plunge has ended up).

i think some of the problem here is people read the height anomolies too literally and assume they show the likely height centre - they don't. You have to imagine the climatological norm to judge that. An example today where the anomolies at day ten can be used to show an easterly when in fact the actual high heights will probably be suppressed too far south to bring my ch more than a slack continental feed. 

Also, the heights don't necessarily reflect precisely where the surface heights will reside. That's a toughy

If anything, your preference for just looking at operationals is more likely to drive you around the twist!

[Mucka]

1 minute ago, Rocheydub said:

'That ECM' was described quite widely as a slider too... where the block over Scandinavia had a low pressure system slide underneath it. I stand over my posts

Anyway, this is just pedantic at this stage.

I'm not trying to be pedantic, just give some clarity.

Basically low pressure going under block is described as undercutting. You can say it has slid under the block if you like but it still wouldn't make it a "slider" which is a specific term to describe low pressure disrupting "sliding" down the Eastern flank of a ridge - at least that has always been my understanding.

People can call things whatever they like for me but it gets confusing if people are using the same terminology to describe very different events.

[Man With Beard]

The GEM, my favourite model of the moment, is interesting this morning. First time it's jumped on the easterly train (well a kind of easterly!) and would tie in extremely well with the top verifying D10 model, which is of course the ECM ensemble mean. 

         

[tight isobar]

On Saturday, January 07, 2017 at 00:09, tight isobar said:

Lol..

The age old argument/disagree. .

Ops against the variable ie ens etc.

Its quite amazing' the full frontal....then reverse psychology of "perception"!  When you see what tickles your fancy..over indulge in your fascinations. .then when minor adjustments cross your path implode- and/or follow thought of others. 

A simple tip would be to evaluate and dissect your own analysis. .

Without the guilt of who thinks what!

 

[Troubleatmill]

Truly hope the 06z operational is wide of the mark,  past the cold spell later this week it has a Bartlett high all the way as the high pressure get slowly pushed SE. Worst case scenario but its a definite possibility with how things look to be playing out. Pretty much as knocker said this morning.

Edited January 9, 2017 by Nicholas B