Model Output Discussion - 31/10/2014 and Beyond

[shaky]

Much better 12z!!lows not as potent and undercutting aswell!!!

[mushymanrob]

re: Mushyman's post above - I too agree the GFS has merit but in 2010, just like in recent weeks, I do feel it falls into the trap of 'predict the same thing and it will be right eventually'. In 2010, it kept predicting a breakdown, and it came many days late IIRC - right now, as I have been mentioning, it keeps building a strong vortex in FI (just occasionally it doesn't) and we're still waiting for it. So I can well see why people are backing the ECM in the next 2 weeks over GFS.

 

oh indeed, statistically the ecm performs better then the gfs, i just think its daft to totally ignore the gfs though , if the pro's dont why should us amatuers?

[Purga]

Thanks for the input Snowballz! Indeed some of the NWP output is starting to look ominously like last year with the jet pushing southwards and a series of LPs heading directly at us - a snapshot example as follows.

There's lots of chance for things to change of course but realistically the short to medium / reliable timeframe is looking wet 'n windy with very little sign of anything wintry apart from the mountain tops in Scotland maybe.

Edited November 6, 2014 by Purga

[Mucka]

Better parallel run too for undercutting, retrogressing heights.

 

 

MetO not really interested yet though.

 

Edited November 6, 2014 by Mucka

[Winter Frost]

Look at the patch of 520 dam over the Atlantic. This is what I was talking about earlier. 

[Barry12]

There's lots of chance for things to change of course but realistically the short to medium / reliable timeframe is looking wet 'n windy with very little sign of anything wintry apart from the mountain tops in Scotland maybe.

 

Are you surprised? it's very rare we getting wintry weather away from the mountains at the start of November.

[Winter Frost]

Its not exactly rare to have snow in November. Perhaps in England but I think you must've forgotten about November 2010.

[nick sussex]

Undercutting drama looks the order of the day!

 

Good trend from the GFS for those looking for cold later in November, we need to see more trough disruption earlier and the troughing to elongate and a separation of of this from being fed by low heights over sw Greenland.

 

For newbies undercutting is the key here, the shape of the low near the UK, so football not good, oval better, elongated suggests high pressure to the ne has won the fight, at this point we'd normally then see a shortwave develop and run se into mainland Europe.

 

As this happens the troughing will give up the ghost allowing high pressure to the ne to extend further west.

[Barry12]

Its not exactly rare to have snow in November. Perhaps in England but I think you must've forgotten about November 2010.

 

Nope. That was the end of November not the start.

 

Also November 2010 was very rare.

Edited November 6, 2014 by Barry95

[Winter Frost]

Nope. That was the end of November not the start.

 

Also November 2010 was very rare.

Yes it was but I have seen lying snow in October. November snow is not rare in NI and Scotland. Anyway this is off topic so moving on.

[karlos1983]

Thanks for the input Snowballz! Indeed some of the NWP output is starting to look ominously like last year with the jet pushing southwards and a series of LPs heading directly at us - a snapshot example as follows.

There's lots of chance for things to change of course but realistically the short to medium / reliable timeframe is looking wet 'n windy with very little sign of anything wintry apart from the mountain tops in Scotland maybe.

 

Looks pretty night and day to me actually Purga

 

and Last Year

 

[Winter Frost]

Undercutting drama looks the order of the day!

 

Good trend from the GFS for those looking for cold later in November, we need to see more trough disruption earlier and the troughing to elongate and a separation of of this from being fed by low heights over sw Greenland.

 

For newbies undercutting is the key here, the shape of the low near the UK, so football not good, oval better, elongated suggests high pressure to the ne has won the fight, at this point we'd normally then see a shortwave develop and run se into mainland Europe.

 

As this happens the troughing will give up the ghost allowing high pressure to the ne to extend further west.

The lows may undercut but where is the cold going to come from? Looking on gfs cold is way up at Greenland so undercutting might not be much use?

 

I personally would prefer the cold to come from there anyway as the Easterlies don't do well here.

Edited November 6, 2014 by Winter Frost

[MR EXTREMES]

if you look at this rather funky stuff you can see clearly why retrogression of heights in scandi to greenland finding it hard although the jet does exit shift northeast towards greenland then arcs round and heads se into west side of france then loops up the north sea blocking the retrogression of heights.

 

although it must be said its very early days and the jet does not seem to have the fuel it had last autumn and winter.

but looking at this rather cool animation of jet stream its rather interesting. http://www.meteociel.fr/modeles/gfse_3d.php?mode=0&lat=50&lon=0&ech=180&zoom=5.4

 

and the 850hpa

http://www.meteociel.fr/modeles/gfse_3d.php?mode=2&gfs05=1

 

and the z500 im more impressed by the animation lol http://www.meteociel.fr/modeles/gfse_3d.php?mode=1

 

but the bottom line is that the beautiful charts of early in the week have really bumped us back to reality tbh my confidence on a cold spell for even the end of this month has certainly decreased hugely.

although still nothing blowtorch more average with wet and windy spell high rainfall totals for scotland and west of england and southern england as fronts stall to our west or over the uk.

 

looking ahead the ideas of northern blocking retrogression seem to have all but gone.

but the hope is maybe events in the strat if they happen could help futher into winter.

 

not confident as i was on a 09/10 winter type.

although as ive suggested still early days but the models have certainly massively backtracked but then this happen early last winter.

not a good omen.

[Mucka]

The lows may undercut but where is the cold going to come from? Looking on gfs cold is way up at Greenland so undercutting might not be much use?

 

There are a few things that would need to fall into place but the cold would come from the NE eventually.

Look at today's 12z parallel and think of the pattern being 500+ miles further West - all the cold pushing into Scandi would be pushing into the UK. That is not an ideal example by any means but it gives you an idea of the sort of flow that could set up were a well positioned cut off high to build to our NW

 

Edited November 6, 2014 by Mucka

[nick sussex]

The lows may undercut but where is the cold going to come from? Looking on gfs cold is way up at Greenland so undercutting might not be much use?

One step at  a time, get the right synoptics the cold will come. If a shortwave develops and runs se into mainland Europe this will support the block. From there things would get more interesting but we still haven't got enough trough disruption earlier, we'll see what the NWP does over the next few days.

[Purga]

Looks pretty night and day to me actually Purga

 

and Last Year

 

I was comparing to later in the season last year when we had the relentless barage of LP's on a southerly jet stalling against a blocking High eg:

[MR EXTREMES]

but then i see this but in reality im very skeptical but even the gfs parallel backs the op.

 

[Panayiotis]

Interesting...

[Ali1977]

GFS P at T252 is much closer to delivering some very cold air from the Northeast, this is the model we should now be focusing on isn't it?

[Snowman.]

 

Very January 2013 like just too far north.

 

If that was say a few hundred miles south that's a snowevent.

Edited November 6, 2014 by SN0WM4N

[Panayiotis]

GEM is also very interesting as well, things are all coming together now...

[Ali1977]

GEM is amazing, what do the experienced folk make of this?  Great half hour of chart viewing, even if it changes next run

Edited November 6, 2014 by Ali1977

[bluearmy]

I think Mr murr will be along once all the 12z runs are out.

just a little too much oomph in the jet at the moment and the wavelengths not adjusted to winter status quite yet. This evolution in a couple weeks time would Look better re cold for here and I suspect we will have to wait until later in the month before the real mouthwatering stuff arrives on the nwp. In the meantime, watching the 'dry runs' is good enough for me!

[shaky]

Very good 12z outputs so far!!!the undercutting has come out of nowhere!!!pretty much what steve murr eluded to earlier with heights being sucked from scandi towards the Iceland/Greenland region!!

[radiohead]

Certainly an interesting end to the GFS (P). Not your typical late Nov pattern....  Just for fun