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Model Output Discussion - 18z 31/10/15 onwards


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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

not sure if the system will let me post this in the format I have created it.

If not I attempted to equate the post above by Frosty for the same date with the 500mb chart

Is the 06z for 12/11/15 that frosty shows, see below for 500mb chart anything like the 500mb anomaly for 6-10 days ahead?

12/11 GFS 500mb

 

Looking at the output below the GFS version is more westerly with a source zone from NE Canada/West Greenland.

The NOAA chart has the source from further south and a south of west flow over the UK.

Fairly minor really and it is possible for a temporary shift in the flow over a 24-48 hour period. So it is a possibility but about 50:50 I would think for now.

NOAA 6-10 current chart

 

Nope but you can check yourself if sufficiently interested with the links below

last evening from NOAA 6-10

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

and Net Wx Extra for 500mb for 11 Nov

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

It's certainly looking more seasonal from the end of this week with wet and windy weather on the way.

post-2026-0-95544400-1446564044_thumb.gi

 

bringing an end to our quiet and sometimes foggy conditions.

 

This more unsettled side of Autumn looks like continuing into week 2 according to the GEFs

A snapshot of this time next week underlines this

post-2026-0-15899800-1446564055_thumb.pnpost-2026-0-74259000-1446564062_thumb.pn

 

the jet firing across the UK with more weather fronts.

 

Generally still on the mild side for most i would think but notice the colder polar maritime air to the north coming closer at times.This is likely to bring some passing snow to the highlands behind the cold fronts.

Nothing more than that i would say for anything wintry for the UK generally.

 

We are looking at quite a normal November pattern with increasing low heights to the north west towards Greenland/Iceland and the Azores high pressure belt-a brisk westerly type of setup.

Edited by phil nw.
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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

We are looking at quite a normal November pattern with increasing low heights to the north west towards Greenland/Iceland and the Azores high pressure belt-a brisk westerly type of setup.

Yes very much so Phil given the outputs this morning. With the lack of Atlantic influence over the past weeks/Autumn it will feel much more seasonal for the time of year, With a strong mobile W/N/W flow.

Edited by Polar Maritime
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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

Yes very much so Phil given the outputs this morning. With the lack of Atlantic influence over the past weeks/Autumn it will feel much more seasonal for the time of year with a strong W/N/W flow.

Yes at least it will clear the air and bring a different feel to things PM.

Spells of wind and rain between the brighter interludes .

Feeling fresher with more of a mix of airmasses off the Atlantic rather than mainly sub tropical scourced air that we have had for quite some time this Autumn so far.

Edited by phil nw.
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Posted
  • Location: winscombe north somerset
  • Weather Preferences: action weather
  • Location: winscombe north somerset

The Gfs 6z again shows a more seasonal pattern by next week with scotland in particular becoming rather cold with increasing Pm influence  and showers turning wintry on northern high ground with overnight frosts, towards mid month it becomes noticeably colder at times further south too. It's a generally unsettled run with bouts of rain and strong winds affecting the uk, especially further north. I think the coldies among us will be pleased to see the chances of relatively colder air at times in the next few weeks looking increasingly likely...not very mild all the time which will make a nice change for this coldie!  :D  :cold:   

It realy warms the cockles of my heart these charts from Frosty ,great forum and nice now we are seeing a possible more mobile pattern setting up looking at current charts ,I have a new toy [samsung tablet ]so i can now sit in front of a warm fire instead of a desk top ,and enjoy our forum ,will try soon to use it on here , :cold:

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Cold enough for snow down to the South coast by the 17th according to the GFS just rolling out....Shame the METO are having none of it!!

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Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK

Looks like the block is finally caving in and the jet has come roaring back into action. Thing is, we'll be into the second week of November without any major zonality and storms, which is mad really. Some divergence about what happens after, but again looks like a typical NW/SE split. staying generally mild for the time being! 

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Note a few models trying to bring a Siberian high into play during week 2

Not sure how common it is for that to begin to move wsw in mid November (assuming it were to happen)

At this point that looks like the only interest from a coldies perspective, hopefully it can force some trough disruption and the jet heading se further west.

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Posted
  • Location: Tullynessle/Westhill
  • Weather Preferences: Cold and snowy or warm and dry
  • Location: Tullynessle/Westhill

Can't really post pictures to illustrate at the moment but ECM, and UKMO to a lesser extent, have a little low developing West of Ireland at 120hrs. This doesn't appear on any of the recent GFS runs. GFS and ECM start to diverge in thier evolution from this point.

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Posted
  • Location: Camborne
  • Location: Camborne

Can't really post pictures to illustrate at the moment but ECM, and UKMO to a lesser extent, have a little low developing West of Ireland at 120hrs. This doesn't appear on any of the recent GFS runs. GFS and ECM start to diverge in thier evolution from this point.

 

I take it this what you mean Ravelin. It's a fairly rapid evolution.

http://www.tropicaltidbits.com/

post-12275-0-11125900-1446580520_thumb.p

post-12275-0-41477700-1446580528_thumb.p

post-12275-0-73309100-1446580535_thumb.p

Edited by knocker
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Posted
  • Location: Tullynessle/Westhill
  • Weather Preferences: Cold and snowy or warm and dry
  • Location: Tullynessle/Westhill

I take it this what you mean Ravelin. It's a fairly rapid evolution.

http://www.tropicaltidbits.com/

I was looking at Meteociel charts, but yes, that looks like it. On closer inspection GFS 6z & 12z do have a possible matching feature but much further south and much less developed at the 120hr mark. On GFS 12z it doesn't really develop as the run progresses, just fizzles out.

Edit: GFS 12z actually has it at 96hr but doesn't develop it as much so it takes a leisurely easterly path as a weak feature before dissipating.

Edited by Ravelin
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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

The anticipated Atlantic 'westerly wind burst' as I like to call it seems to have been subtly upgraded and moved a little forward in time when taking the past 48 hours of runs into consideration. The result is more in the way of disturbances affecting the UK, in fact hardly a day looks dry and the rain may manage to prove more substantial even across the SE at times.

 

The way things are shaping up for early next week reminds me of winter 2006/7 which down this way brought lengthy spells of often windy, mostly mild weather with plenty of rain spells but most of the rain light. I remember not once having to wear more than a light rain jacket.

 

The GFS det. runs have been very keen on developing a Canadian trough in 9-11 days time, which tends toward a negative tilt and so allows a ridge to develop in the vicinity of Greenland for a time, with wintry results for the UK. However, I'm not seeing that much support from the GEFS - though I've only had a quick rummage through them to be fair. Perhaps more significant is that the ECM det. has that potential Canadian trough getting stuck way down south with a ridge through Canada - if the NAO was to go negative from there I suspect it would end up west-based with an Atlantic trough delivering a mix of TM and PM airmasses to our shores.

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Posted
  • Location: Evesham/ Tewkesbury
  • Weather Preferences: Enjoy the weather, you can't take it with you 😎
  • Location: Evesham/ Tewkesbury

Good Evening All.... Well the models tonight are really like a breath of fresh air if you want a change from the stagnant weather of recent weeks! The Euro high looks to demise fairly quickly and the Jet stream steps up some gears so at last some more interesting weather , but I certainly don't see anything too cold in the outlook, but yes temperatures falling to normal levels and a bit below average is likely with snow on the uplands of picticularly Northern Britain.....and even North Wales. Good to see a change of weather, we have had the benign ,quiet conditions for a long time now, Time to Crank up that Engine.... :cold:  :shok:  :clap:  :good:

post-6830-0-27218400-1446583071_thumb.pn

post-6830-0-84270100-1446583157_thumb.pn

Edited by ANYWEATHER
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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

hi nick, i have a little issue with your statement. if the GFS was improved/upgraded in the spring of this year, with the help of the ECMWF team, firstly why would they leave a "known bias" in the program and secondly, if the new GFS hasnt yet been run through an autumn/winter season, how would we know what 'bias' if any, it has regarding these (less benign) seasons. my point being, since the upgrade, there cant be any real 'known bias' until it has been running for at least a full year to see where it may have made consistent errors regarding certain weather patterns. we cant expect the same old GFS this winter but we might find out if they've 'fixed' it!

Fair enough, however so far the new GFS upgrade has resulted in this:

 

850 temp correlation day 6

 

ECM 0.773

GFS 0.729

 

day 8

 

ECM 0.570

GFS 0.478

 

day 10

 

ECM 0.362

GFS 0.272

 

These were the main biases as observed in the USA for the GFS,

 

Prediction of southward progression of cold air over done

Model a bit too extreme in temp patterns beyond 84 hours

Precip Type Algorithm off of GFS  too eager to depict snow 

Over forecast of cyclogenesis east of Rockies

 

That list won't come as a surprise, we'll of course reserve judgement to see how the GFS does after the winter.

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Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK

Still not looking desperately unsettled - as in the storm track is still clipping the NW rather than ploughing through....ECM doesn't bring the 0c isotherm in until 240 hours out. Either way, it's flattening out.

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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

Still not looking desperately unsettled - as in the storm track is still clipping the NW rather than ploughing through....

 

The GFS has the vast part of Scotland under severe Gales, So a little more than a clip i would say. Still time for adjustment all the same.

post-12319-0-61655100-1446584666_thumb.p

post-12319-0-45392200-1446584674_thumb.p

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Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

hi nick, i have a little issue with your statement. if the GFS was improved/upgraded in the spring of this year, with the help of the ECMWF team, firstly why would they leave a "known bias" in the program and secondly, if the new GFS hasnt yet been run through an autumn/winter season, how would we know what 'bias' if any, it has regarding these (less benign) seasons. my point being, since the upgrade, there cant be any real 'known bias' until it has been running for at least a full year to see where it may have made consistent errors regarding certain weather patterns. we cant expect the same old GFS this winter but we might find out if they've 'fixed' it!

 

We had the new GFS all of last winter - firstly, as a very protracted parallel run (going 'live' kept being postponed) then operational from mid January. From memory, it never subscribed to some of the more amplified forays of the ECM but at the end of the day there was very little to test it in the way of synoptics outwith normal westerly climatology.

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Posted
  • Location: Cork, Ireland.
  • Weather Preferences: Storms frost snow heatwaves
  • Location: Cork, Ireland.

Judging by chart number one, it would appear our euro block friend will have become a distant memory. However, going by the day 10 chart one can clearly see an Atlantic with much less oomph yet again as well as a dramatic increase in height rises to our south. Would certainly seem to suggest a relatively short lived unsettled phase before a gradual return to more of what we've become accustomed to this autumn. :nonono:  

post-17830-0-41019300-1446584823_thumb.j

post-17830-0-99446300-1446584837_thumb.j

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