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Checking The 500mb Anomaly Charts Against The Actual One


johnholmes

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

Here is the No 17 check

Overall the 17 checks are giving 63% at worst and 73% at best so I am quite happy with how the checks are proceedding, many more to go though.

No 17 from 8 July for 18 july 2012.pdf

Thanks for that John-some sterling work you are doing on these over a long period.Much appreciated.

Btw are you and your PC friends again?I would guess from your last post you are able to view and download all the data again?

Regards,Phil.

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

Thanks for that John-some sterling work you are doing on these over a long period.Much appreciated.

Btw are you and your PC friends again?I would guess from your last post you are able to view and download all the data again?

Regards,Phil.

thanks Phil

you could say more or less-see my post a few days ago in the thread I opened about my problems. My thanks for your help in that.

regards

John

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  • 2 weeks later...
  • 3 weeks later...
Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

Not the routine check-that is due tomorrow but the interesting situation of differences showing in the synoptic verses the anomaly predictions last week for the BH weekend.

Comparing the predicted charts from Tuesday-14-15 august.pdf

below is the latest 6-15 day outlook from UK Met

UK Outlook for Thursday 23 Aug 2012 to Saturday 1 Sep 2012:

The northwestern half of the UK will be mostly unsettled, often with strong winds. Showery conditions are likely to prevail, with some more persistent rain around the first weekend, although some drier and brighter spells are possible too. Less unsettled in the south and east where it will be warm at times, although even here some spells of persistent rain are likely, mainly during the bank holiday weekend. Continuing changeable right up to the beginning of September. Daytime temperatures generally around average or a little below, with the best chance of occasional above average temperatures in the southeast. As the Paralympics draw closer the Met Office will have local forecasts so that everyone can make the most of the Games experience.

Updated: 1157 on Sat 18 Aug 2012

To me that seems to suggest they still feel the upper air pattern will be almost a compromise, not unusual for this to happen in meteorology, between the GFS/ECMWF synoptic outputs and the 500mb versions.

It will be interesting to see just what the pattern is this time next week?

Edited by johnholmes
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Posted
  • Location: st albans
  • Location: st albans

john, the anomoly charts you show are a mean for the 6/10 day timeframe. in that context, a nw flow would not have been right. infact, with a depression looking to come trundling in beginning next weekend, a flow south of west seems likely to prevail. the other thing that strikes me as an anomoly (if you'll pardon the pun) is that the 500mb chart you posted is derived from the op runs only so how can it fundamentally be at odds with the op runs you are checking against ? i do accept that the noaa cpc anomoly charts were showing a longwave trough hanging back to our sw which indicated a long sw flow into the uk. the reality appears to be a marked trough, but one which is on a more w/e axis than sw/ne.

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

the latest check No 19

No 19 from 9 August for 19th.pdf

only just noticed the comment prior to this-will reply after having a bite to eat.

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

Hi ba

Thanks for your post and its good to see someone reads my musings now and then.

Yep I am aware of just where the data for any of the charts originates from although I do, as we have discussed previously, disagree with your view. That is I see it as a useful exercise to check one with the other provided it is done using ECMWF, GFS and NOAA anomaly charts and that all 3 for several days have been suggesting a similar outcome to the 500mb flow. As to why if they are from the same start time why there is quite often a difference is something NOAA have never really satisfactorily explained to me. They do admit that the anomaly charts are far less variable in their output with GFS data.

But it will be interesting to see how next Saturday turns out at 500mb.

Certainly this spell of warm or very warm southerlies was well predicted by the anomaly charts which is not the case as I saw it with the 4x or 2x outputs until quite a bit closer to the start of the warmth for many parts of England. I should add I only saw some runs as I was away on holiday until 7 August.

off now for a bite to eat

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Posted
  • Location: South Gloucestershire BS35
  • Weather Preferences: Severe weather enthusiast
  • Location: South Gloucestershire BS35

Thanks for that John. Gives me something to read to help learn and understand more, rather than just focusing on what the main model charts show run by run every day, without comparing them across a longer time period. Some good work :)

Edited by Chris K
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  • 2 weeks later...
Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

check No 21 and not perfect by any means but it gave me reasonable guidance about the surface weather I feel-please feel free to comment against that idea if you wish.

No 21 check done 10 September 2012.pdf

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  • 2 weeks later...
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Posted
  • Location: Longwell Green, near Bristol
  • Weather Preferences: Storms, Gales, frost, fog & snow
  • Location: Longwell Green, near Bristol

Any thoughts on the latest 500mb charts John?

Not sure where to find them & just wondered if they resembled anything like the operational data?

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  • 2 weeks later...
Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

sorry AWD only just noticed this-no point in replying as its now the 24th!

No 25 in pdf format below-not bad giving reasonable guidance on it being mild

No 25 check 14-24 Oct 12.pdf

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

No 27 below, a very good one but then it predicted no change so the next one could be interesting!

No 27 from 6 to 16 Nov 12.pdf

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Posted
  • Location: Newbury, Berkshire. 107m ASL.
  • Weather Preferences: Summer:sunny, some Thunder,Winter:cold & snowy spells,Other:transitional
  • Location: Newbury, Berkshire. 107m ASL.

No 27 below, a very good one but then it predicted no change so the next one could be interesting!

No 27 from 6 to 16 Nov 12.pdf

When and where will you be posting your next analysis John? I very much appreciate the effort that goes into these summaries. Posted Image

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

If you mean the checks then I start No 28 on Monday so that takes it out to 29 November.

If you mean the usual Friday 6-20 day glimpse ahead then I'm just doing it, could be another hour or so before I post it.

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  • 7 months later...
Posted
  • Location: south wales uk
  • Weather Preferences: hot and sunny
  • Location: south wales uk

Hi John,quick question for you,on these charts,

http://www.meteo.psu.edu/~fxg1/ECMWF_12z/test8.gif

am i correct in thinking red=higher pressure,blue=lower...or is not as simple as that?,ive tried researching but so far not getting much luck?...

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

Hi John,quick question for you,on these charts,

http://www.meteo.psu.edu/~fxg1/ECMWF_12z/test8.gif

am i correct in thinking red=higher pressure,blue=lower...or is not as simple as that?,ive tried researching but so far not getting much luck?...

 

see my last post in the model thread-hope that helps

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Posted
  • Location: south wales uk
  • Weather Preferences: hot and sunny
  • Location: south wales uk

see my last post in the model thread-hope that helps

Thankyou John

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  • 4 weeks later...
Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

from the model thread today 25 July

How did the anomaly charts end up from about 10 days ago?

Before I went on holiday I posed the thought, I wonder which if any of the 3 I use would look most like the actual 500mb chart today.

 

I wonder which of 6-10 or 8-14 or ec/gfs will be nearest when I log on Thur 25 july??

 

Below are the outputs from NOAA and then ECMWF-GFS. Below that is the actual 06z Extra chart from GFS this morning.

 

 

 

 

 

Well, the 6-10 NOAA kept a similar pattern to what was there on the 14th but the 8-14 shifted that to give a trough as the dominant feature 22-28 July. Not a really marked feature but a change from what was around at the time and for much of last week although I was not able to see the 500mb actual pattern.

The ECMWF-GFS kept the idea of the ridge and +ve heights in the UK area of interest.

 

Looking below and it is pretty obvious that the 8-14 NOAA had the idea pretty near. The other outputs I suspect were more relevant over the days preceding the last couple.

Some may disagree but again it looks to me that the 8-14 NOAA gave a good indication of the change in major weather pattern affecting the UK?

 

 

Using that, assuming it has been consistent from that issue on the 14th, which on the few occasions I saw it whilst on holiday it was, then it would allow a forecaster to predict the change in emphasis. From hot and dry to warm/very warm and muggy with outbreaks of showers or thunderstorms as the upper trough began to have more influence than the upper ridge.

 

no charts so you need to go to the model thread, when I can find it I will drop the pdf in the other thread as well.

Edited by johnholmes
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