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Model Output Discussion:


Methuselah

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Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

Well the GEFS control run clearly shows how uncertain the outlook is and the same applies to the ECM control run. Remember the control runs are using exactly the same data as the operationals and this data isn't tweeked at the beginning of the run. Whats noticeable is how the control runs diverge in a relatively early timeframe which is surprising TBH.

All this means is the 12Z ECM could show a S/SW/SE/E/NE,ly such is the uncertainity.

My own personal view is this will not be sorted out today. The period between +120/+144 could be modelled wrongly IMO which is why I feel tomorrows 12Zs could be completely different to what we have seen this morning.

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Posted
  • Location: Dorset
  • Location: Dorset

ps Iceberg you can get away with saying the GFS is meaningless, I got attacked (not by you) yesterday for saying the ECM was possibly too progressive? pffft

Neat isn't it :)

GFS ENS for the parellel demonstrates this perfectly though.

The 00Z has NO runs going to -15.

The 06Z has 6 runs that hit -15 850s at some point.

The 06Z has also seen a 4C shift in the 850 mean (downwards).

ECM EPS for 00Z London though show no preference for anything, everything has pretty much equal support from the ops which was very much on the up side of the members to a very cold easterly.

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Posted
  • Location: Blackburn, Lancs
  • Location: Blackburn, Lancs

So much scatter amongst each model run at the moment, I feel it's better to wait until weekend, to see how things firm up for next week. I've never seen so much chopping and changing!!

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Posted
  • Location: Blofield Heath
  • Location: Blofield Heath

I think the good thing is that we always seem to get some of the members going for a colder solution on the ensembles on or around the 8th Feb which must mean that the possiblity of cold is no way near from being binned.

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I know this is a silly question, but what is the difference between the GFS and GEFS? :) I seriously don't know.

SS2

GEFS are the GFS ensembles, 20 lower resolution runs of the GFS run with slightly different starting data (apart from control).

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Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

I know this is a silly question, but what is the difference between the GFS and GEFS? :) I seriously don't know.

SS2

The GFS is the operational run. The GEFS are the ensembles which has a control run followed by 20 members. Just to confuse you further we also now have the GEFS parallel runs which also consist of a control run followed by 20 members.

Basically back in the 1990s they decided they also need to use ensembles to check the reliablity of the operational runs. What they basically do is slightly change the starting point (except control run). The main purpose is to rtry and take into account the kaos theory that applies in the climate but also these computer models.

The Kaos theory is why model output will always be uncertain beyond +144. Personally my view is they will never be able to take this into account despite increasing computer power.

P.S isn't a silly question. Never be afraid to ask as im always willing to help.

Edited by THE EYE IN THE SKY
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Posted
  • Location: Bishopbriggs, near Glasgow
  • Weather Preferences: Cold snowy winters, warm dry summers
  • Location: Bishopbriggs, near Glasgow

The GFS is the operational run. The GEFS are the ensembles which has a control run followed by 20 members. Just to confuse you further we also now have the GEFS parallel runs which also consist of a control run followed by 20 members.

Basically back in the 1990s they decided they also need to use ensembles to check the reliablity of the operational runs. What they basically do is slightly change the starting point (except control run). The main purpose is to rtry and take into account the kaos theory that applies in the climate but also these computer models.

The Kaos theory is why model output will always be uncertain beyond +144. Personally my view is they will never be able to take this into account despite increasing computer power.

P.S isn't a silly question. Never be afraid to ask as im always willing to help.

Thank you TEITS, I have learned something else today, it seems the more models that come out the more confused I am becoming lol.

SS2

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Posted
  • Location: st albans
  • Location: st albans

Neat isn't it :)

GFS ENS for the parellel demonstrates this perfectly though.

The 00Z has NO runs going to -15.

The 06Z has 6 runs that hit -15 850s at some point.

The 06Z has also seen a 4C shift in the 850 mean (downwards).

ECM EPS for 00Z London though show no preference for anything, everything has pretty much equal support from the ops which was very much on the up side of the members to a very cold easterly.

Iceberg - the parallel ens showing 06z are yesterdays. if todays 06z run, currently up to T72 have 6 runs hitting -15c, i'll eat my hat.

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Posted
  • Location: Weston Super Mare , North Somerset
  • Location: Weston Super Mare , North Somerset

Keep the Faith people . A patten change is coming , I think to many people have got that 8th of Feb date stuck in there head . Give or take a few days , After all even if it was dry and drizzle or just damp , When was the last time we seen a February without any kind of Easterly , I can't remember. Itis the most common time of year for an Easterly to happen and this year background signals are stronger than average . The Models always go from one solution to another during a patten change anyway .

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

So much scatter amongst each model run at the moment, I feel it's better to wait until weekend, to see how things firm up for next week. I've never seen so much chopping and changing!!

If the UKMO model is correct we will be virtually in the easterly by then lol.

You are right though it may take another day or two for model agreement.

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Posted
  • Location: Bournemouth
  • Weather Preferences: Thunderstorms
  • Location: Bournemouth

The GFS is the operational run. The GEFS are the ensembles which has a control run followed by 20 members. Just to confuse you further we also now have the GEFS parallel runs which also consist of a control run followed by 20 members.

Basically back in the 1990s they decided they also need to use ensembles to check the reliablity of the operational runs. What they basically do is slightly change the starting point (except control run). The main purpose is to rtry and take into account the kaos theory that applies in the climate but also these computer models.

The Kaos theory is why model output will always be uncertain beyond +144. Personally my view is they will never be able to take this into account despite increasing computer power.

P.S isn't a silly question. Never be afraid to ask as im always willing to help.

Hi TEITS

Another basic question... I understand the Operational and 20 members, but can you explain what the Control run is and how it's worked out for me? Also, has the parallel run now taken over from the old GFS model?

Cheers

Luke

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Posted
  • Location: Shirley, Croydon, Greater London
  • Location: Shirley, Croydon, Greater London

If the UKMO model is correct we will be virtually in the easterly by then lol.

You are right though it may take another day or two for model agreement.

I agree. I remember the GFS was going for Easterlies and would not back off for a few days. ECM showed Easterlies at first. UKMO was having none of it and rightly so as it turned out to be correct. UKMO 12Z will be crucial IMO. I'm more confident with a colder outlook after the latest MetO update.

Edited by yamkin
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Guest North Sea Snow Convection

If the UKMO model is correct we will be virtually in the easterly by then lol.

You are right though it may take another day or two for model agreement.

Latest METO update suggests a colder solution more likely than the operationals show (except UKMO) taken at face value.

It looks clear enough to me that there is good support for the notion that the atlantic is indeed being overplayed (speaking of ppn perhaps fizzling out before it reaches eastern parts) and the uncertainty imo is more in favour of things trending colder over the next day or so with the drier colder air to the north and east in the ascendancy. Hence, as you say, we may well see that agreement in the models fairly shortly

Edited by North Sea Snow Convection
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Latest METO update suggests a colder solution more likely than the operationals show (except UKMO) taken at face value.

It looks clear enough to me that there is good support for the notion that the atlantic is indeed being overplayed and the uncertainty imo is more in favour of things trending colder over the next day or so with the drier colder air to the north and east in the ascendancy. Hence, as you say, we may well see that agreement in the models fairly shortly

As the days grow longer the cold gets stronger?

Yes i completely agree, the atlantic is not in control of our weather, it looks sluggish to me and prone for HP to take control from the weekend.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Yes i completely agree, the atlantic is not in control of our weather, it looks sluggish to me and prone for HP to take control from the weekend.

To be honest, the models are showing more chance of southerly winds than easterly from thursday onwards with the atlantic holding the upper hand.

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Posted
  • Location: Leicestershire (hinckley)
  • Location: Leicestershire (hinckley)

There is an excellent Easterly showing on the GEFS parallel control at +t384

post-9179-12651138637688_thumb.png

post-9179-12651138746388_thumb.png

A snow fest if ever I saw one! - any takers

That wouldnt be a snowfest, especially for those further north. most of the country would be dry with showers in the east south east most likely.

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

I think there is another option and that is that as far as northern blocking goes

the dam breaks as it were (blocking being under modeled ) and every thing is

surpressed further south and weaker rather than needing the energy to undercut.

Just a thought thats all.

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Posted
  • Location: Ware, Herts
  • Location: Ware, Herts

To be honest this thread is kind of an irrelavence at the moment, with so little agreement and chopping and changing, the answers are not within the model output.

When we have such divergence we need to look to other sources such as the teleconnections and senior forecasters for a solution.

I honestly don't have a clue which way it will go, although if we look for a half way house, the north east may retain the cold with much milder weather into the south west?

I absolutely agree with this. With FI at 144 (maybe even 120), should we look to when the set up was similar to what it is now? Has it ever been like this? Have the models ever had to cope with such synoptics before?

One thing I know is that Michael Fish will have his work cut out when he returns for this weekend's forecast :lazy:

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Posted
  • Location: Abbeymead ,Glos Member Since: July 16, 2003
  • Weather Preferences: Hot and thundery or Cold and snowy.
  • Location: Abbeymead ,Glos Member Since: July 16, 2003

There is an excellent Easterly showing on the GEFS parallel control at +t384

post-9179-12651138637688_thumb.png

post-9179-12651138746388_thumb.png

A snow fest if ever I saw one! - any takers

BANK!

Looking around my area. The ensembles have been odd for a few days now.

t850Gloucestershire.png

Why that control is like that? any ideas.

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Posted
  • Location: Bournemouth
  • Weather Preferences: Thunderstorms
  • Location: Bournemouth

BANK!

Looking around my area. The ensembles have been odd for a few days now.

t850Gloucestershire.png

Why that control is like that? any ideas.

Please could someone explain what the Control Run is - it's clearly a run in its own right and not a mean of the ensembles.

Cheers

Luke

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Posted
  • Location: Banned from Posting, Not happy
  • Location: Banned from Posting, Not happy

Whats happened to the massive easterly progged by the ECM 12z yesterday ?

I cant believe my eyes, its totally gone, and in its place the 00Z progs a sotherly out to T240 ??

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Posted
  • Location: Heswall, Wirral
  • Weather Preferences: Summer: warm, humid, thundery. Winter: mild, stormy, some snow.
  • Location: Heswall, Wirral

Judging by the ensembles the thing that they are all showing is after a rise there will most likely be a small dip and then a potential rise, this basically is continuation of the pattern we have had recently.

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Posted
  • Location: Pontypridd, Wales 240m asl
  • Location: Pontypridd, Wales 240m asl

Right now due to the current set up the science of weather modeling is virtually impossible - If you look further than about 24 - 48 hours you are probably wasting your time cause it'll all be different on the next set!

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Posted
  • Location: Dorset
  • Location: Dorset

The control run is the ops run, ran at the same resolution as the ensembles.

You would hope to get some agreement from either the ENS mean, the ops run or the control run, that all 3 seem to bare no resemblence to each other or to the other models such as UKMETO, nor the ECM EPS which have no pattern, strongly indicates that no model has a clue atm !.

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