General Model Output Discussion

[West is Best]

I know where a Bartlet can be situated but look at the low heights towards the east and the angular shape of the high over Scandinavia. I really can't see that forming a conveyor over us but I suppose you never know.

A Bartlett high sits to our south from T144 onwards on both GFS and UKMO ... ECM is much better.

Nick I don't share your faith in the omniscience of the upstream signals. If GFS and UKMO are showing a Bartlett from T144 onwards there's a good reason why.

Edited January 14, 2010 by West is Best

[Thundery wintry showers]

It's not a Bartlett at all, the high is too far north and east. The Bartlett is a high that sits to the S and SE of Britain feeding very warm tropical maritime south-westerlies in, with a lot of cloud and rain for the NW but drier, and in some cases sunny, weather towards the SE, an extreme case of a Bartlett being the second week of February 1998.

If the lows can't get part the meridian because of a huge high over Siberia then it isn't a Bartlett. It can develop into one if the main Siberian High gets shunted away eastwards and a breakaway high establishes over western and central Europe, but as yet there are no clear-cut signs of this happening on any of the models.

[nick sussex]

well another mild run by the ECM any possible cold will happen in F1 which chops and changes like the weather its self anyway looks like a simple forecast to make for next week mild wet and windy the normal

Do you have access to a different ECM model? there are several chances for snow on the ECM and its cold for most of the UK from 120hrs which isn't FI! Whilst I think the models are in a bit of a mess the upstream pattern does not suggest mild, more average in the west and colder further east.

[Nick L]

well another mild run by the ECM any possible cold will happen in F1 which chops and changes like the weather its self anyway looks like a simple forecast to make for next week mild wet and windy the normal

What has motorsport got to do with anything...

[West is Best]

I would ask certain people to do some research on what exactly the Bartlett high is before terrifying some net weather members into reaching for the prozac!

I'm extremely familiar with it Nick.

The slug sits to our south c. Spain, France, Med and effectively dominates by blocking any helpful meridional patterns.

There's a whopping great Bartlett in position on the 12z GFS from T126 onwards. You and I might not like it, but it's there.

[TEITS]

Have to say the posts this evening are even more baffling than the models.

The ECM tonight illustrates very nicely that next week the outlook is uncertain. Not much point making any other comments until the models come into some agreement.

[nick sussex]

A Bartlett high sits to our south from T144 onwards on both GFS and UKMO ... ECM is much better.

Nick I don't share your faith in the omniscience of the upstream signals. If GFS and UKMO are showing a Bartlett from T144 onwards there's a good reason why.

OMG there is no Bartlett high! Please read TWS post, or can someone stick an archive chart up so we can just move on from this talk of Bartletts before i lose it big time!

[Blizzardo]

I like the ECM tonight from a cold and snow prospects viewpoint. I know its a bit away but there is a train of lows running under the UK at 168 hrs and from then on low pressure seems to be doing its best to drag the cold air towards us.

[Nick L]

I'm extremely familiar with it Nick.

The slug sits to our south c. Spain, France, Med and effectively dominates by blocking any helpful meridional patterns.

There's a whopping great Bartlett in position on the 12z GFS from T126 onwards. You and I might not like it, but it's there.

This, Bartlett:

http://www.wetterzentrale.de/pics/archive/ra/1998/Rrea00119980213.gif

This not Bartlett:

http://charts.netweather.tv/gfsimages/gfs.20100114/12/126/h500slp.png

Bloody hell, some people need to stop being so negative when there is no reason to be.

[igloo]

Do you have access to a different ECM model? there are several chances for snow on the ECM and its cold for most of the UK from 120hrs which isn't FI! Whilst I think the models are in a bit of a mess the upstream pattern does not suggest mild, more average in the west and colder further east.

how some people are in denial on what the models are showing for the next 5-6 days

[I remember Atlantic 252]

Just wondering which model Michael Fish has used, because his forecast looks very promising, but models dont show that, does look good though tue/wed with cold continental air on gfs 12Z

[West is Best]

OMG there is no Bartlett high! Please read TWS post, or can someone stick an archive chart up so we can just move on from this talk of Bartletts before i lose it big time!

I can only assume Nick that you're looking north-east which is not where a Bartlett high sits. Here's a Bartlett high. Go south from Britain to southern France and this is a Bartlett:

That's from the 12z GFS ... T150

And this explains a Bartlett High:

'What 'high' blocks there have been stay teasingly just too far east and more often than not, a broad band of high pressure extends from the Azores area, east-north-eastwards towards the Biscay / English Channel region - perhaps now & then displaced towards the Alps ...The apparently semi-permanent belt of high pressure in the 'wrong' place has been christened ... "The Bartlett High", in honour of Paul Bartlett'

From 'What is a Bartlett High' http://weatherfaqs.org.uk/node/117

Notice the remarks about how the typical other block which accompanies out north-east will always remain tantalisinly out of reach once a Bartlett High takes a hold to our south.

Doesn't mean it will happen, but it's most certainly there on both the GFS and UKMO.

Edited January 14, 2010 by West is Best

[snowingtequila]

how some people are in denial on what the models are showing for the next 5-6 days

please show some examples, I am in no denial, I don't really care what it does I have a lot of outdoor work to do so would prefer some dry weather, mild or cold but I do not see what you are seeing on the ECM so please show me the charts you are looking at. please?

[LomondSnowstorm]

I'm extremely familiar with it Nick.

The slug sits to our south c. Spain, France, Med and effectively dominates by blocking any helpful meridional patterns.

There's a whopping great Bartlett in position on the 12z GFS from T126 onwards. You and I might not like it, but it's there.

http://charts.netwea...147/h500slp.png

http://www.wetterzen...00119980210.gif

Surely in the first chart the most prominent feature is the high to our northeast. On the '98 chart there is no blocking at all to our north, with a strong high right across central and southern Europe, while in the gfs 12Z there is no sign of that, merely the usual slightly higher pressure towards Portugal. To me, the 12Z looks more of a battleground, with the milder air to the west pushing against the cold continental air to our east, while the archive chart is clearly just atlantic domination all the way.

LS

Edited January 14, 2010 by LomondSnowstorm

[nick sussex]

how some people are in denial on what the models are showing for the next 5-6 days

I'm not in denial just stating what the ECM showed and if you read my post i said from 120hrs!

[Cloud 10]

bartlett>>> not bartlett>>>

[TEITS]

how some people are in denial on what the models are showing for the next 5-6 days

I think your misreading the ECM.

Anyone on the N side of the LP will see snow.

Those who see rain are likely to see this turn to snow as the LP clears.

Exactly the same happens again.

So because of the disagreement with the models a realistic forecast for next week is uncertain!

[Polar Continental]

Certainly not Mild!

The ECM is a cold run, not mild and definitely trending the right way for renewed very cold from the east. Those low pressure areas are undercutting the block, if this run holds, expect cold easterly winds, ok, not cold enough for widespread snow on low ground, but there is time for this to change.

If the ECM went out a little further, I would say that high to the north east of Scotland and over Scandinavia would intensify, reinforcing northern blocking.

Edited January 14, 2010 by Polar Continental

[Tim Bland]

This, Bartlett:

http://www.wetterzentrale.de/pics/archive/ra/1998/Rrea00119980213.gif

This not Bartlett:

http://charts.netweather.tv/gfsimages/gfs.20100114/12/126/h500slp.png

Bloody hell, some people need to stop being so negative when there is no reason to be.

Don't lower yourself to their level Nick. The poster on the previous page who wrote Bartlet in bold did it for a reason - To spark a reaction, and they got it!

What I can see is potentialy an exciting period of weather comming up. On Sunday we had "The holy grail straight Easterly" and all we got was a thaw and a few flurries. Next week we COULD see the uk being a battle ground with cold to the east and atlantic to the west. IF this meets over us then there COULD be heaps of snow! Much more interesting IMO than waiting for a light snow shower to make its way inland.

[Jason T]

Hi all, look guys i am fairly new on here, and i find it well interesting. Could you agree to disagree.

[cooling climate]

OMG there is no Bartlett high! Please read TWS post, or can someone stick an archive chart up so we can just move on from this talk of Bartletts before i lose it big time!

Is,is that a BARTLETT I see?

LOL sorry couldn't resist. Funny how the GFS goes off the idea of a continental influence only for the

Euro's to take up the baton again, well the ECM anyway.

[Mark Bayley]

An interesting ECM. That low would probably bring rain to most however some snow to high ground and on its northern edge would have been possible.

850hpa temps

Then shows colder air returning, at least for the northern half the the UK. A bit Mild beforehand, but nothing exceptional GFS and UKMO on the other hand aren't as good. But they are not a disaster, Certainly not bartletts!

[Mr Sleet]

I can only assume Nick that you're looking north-east which is not where a Bartlett high sits. Here's a Bartlett high. Go south from Britain to southern France and this is a Bartlett:

That's from the 12z GFS ... T150

And this explains a Bartlett High:

That is not a Bartlett, it's transient Azores ridge, and a pretty pathetic one at that!

[Thundery wintry showers]

I've read and re-read the section on the Bartlett High- and there's nothing at all about near-misses from the east. What it says is that cold incursions are restricted to brief polar maritime bursts from the W and WNW. It is a high that ridges up from the Azores, and sometimes goes as far as the Alps, and "easterly potential" is practically non-existent.

In the current setup highest pressure is over Siberia not the Azores. The setup isn't totally dissimilar to the Bartlett but there are some key differences.

[West is Best]

[surely in the first chart the most prominent feature is the high to our northeast.

The problem with a Bartlett in place like that on GFS and UKMO is that the high to our north-east will never be able to extend its influence westwards. And with the Bartlett in place you can end up forever gazing at something that just ain't gonna happen ...