Model Output Discussion 19th January 2014-18z onwards.

[MR EXTREMES]

Sorry for the commentary

 

UKMO 96 - Awsome

 

http://www.meteociel.fr/ukmo/runs/2014012312/UN96-21.GIF?23-17

 

Draw your eyes towards Southern Norway & the deep cold angle.....

 

S

nothing wrong with your commentary steve and I tell you what the gfs is not bad either has it had a revamp lol.

I noticed on the gfs 12z that the low has moved a couple hundred miles south more than the 6z great and I was a little worried to start with on the ukmo but its turning out nice to.

[Mucka]

Sorry for the commentary

 

UKMO 96 - Awsome

 

http://www.meteociel.fr/ukmo/runs/2014012312/UN96-21.GIF?23-17

 

Draw your eyes towards Southern Norway & the deep cold angle.....

 

S

 

Yup very consiistent and it is still backing the pattern West as well. 96h comparison today/yesterday

 

[MR EXTREMES]

gfs the azores ridge looks like our friend for once slowing the next low out of the states allowing a chance for better ridging and amplification of heights could be a stella run from the gfs.

 

as steve murr said lastnight knife edge 50/50.

Edited January 23, 2014 by emotional rollercoaster

[frosty ground]

I'm sure the Dep. Chief won't object to me citing him directly on his briefing issued just before midday today (the emphasis italics are his, not mine), so to avoid paraphrashing or confusing the UKMO underpinning behind the 6-15d forecast. This should speak for itself re your queries and why a return to zonal is the form horse further ahead:

 

"...after a quasi-meridional period in approx the day 6 to 8 day f/c period in which a filling area of low pressure moves SE’wards across UK, there is a return thereafter to the generally zonal pattern already seen for most of this winter. There are differences between models.... wrt the detail of the return to a more zonal pattern, but very little disagreement that this broadscale evolution will occur.....

Examination of Shannon Entropy f/c output from both EC and MOGREPS both have low entropy / high confidence early in the 6-10 day period and later (in the trend period), with a spike of high entropy / low confidence around days 8 or 9, relating to

the detail of the return to zonal flow."

So regardless of how we get to day 10 from day 6 there is good agreement that a zonal flow will re-establish it's self across the British isles.

[Biensie]

I'm sure the Dep. Chief won't object to me citing him directly on his briefing issued just before midday today (the emphasis italics are his, not mine), so to avoid paraphrashing or confusing the UKMO underpinning behind the 6-15d forecast. This should speak for itself re your queries and why a return to zonal is the form horse further ahead:

 

"...after a quasi-meridional period in approx the day 6 to 8 day f/c period in which a filling area of low pressure moves SE’wards across UK, there is a return thereafter to the generally zonal pattern already seen for most of this winter. There are differences between models.... wrt the detail of the return to a more zonal pattern, but very little disagreement that this broadscale evolution will occur.....

Examination of Shannon Entropy f/c output from both EC and MOGREPS both have low entropy / high confidence early in the 6-10 day period and later (in the trend period), with a spike of high entropy / low confidence around days 8 or 9, relating to

the detail of the return to zonal flow."

 

 

 

 

Sorry to be so ignorant but what does that mean in layman's terms?  Thanks

[MR EXTREMES]

with the progressive nature which will win first on the gfs I feel that the easterly is game on ?

 

[Summer Sun]

Wintery showers continue in parts of Scotland at t144

 

[Frosty.]

http://modeles.meteociel.fr/modeles/gfs/runs/2014012312/gfsnh-0-102.png?12GFS 96-Were in business thus far- all12z signs point towards the UKMO 00z.S

Reminds me of a song, there's no business like snow business ..:-) great to see the models firming up on a blast of wintry weather next week, as basil brush would say..Boom Boom.

[Timmytour]

If....and a bif IF,,,,the Easterly gets in post T144....it's hard to see the Atlantic coming back easily with the way things are shaping up on the GFS

[frosty ground]

with the progressive nature which will win first on the gfs I feel that the easterly is game on ?

 

For 48 hours at the most, We really need some colder air to get mixed in if we wish to see some low level snow during this short cold snap!

Edited January 23, 2014 by frosty ground

[MR EXTREMES]

I'm sure the Dep. Chief won't object to me citing him directly on his briefing issued just before midday today (the emphasis italics are his, not mine), so to avoid paraphrashing or confusing the UKMO underpinning behind the 6-15d forecast. This should speak for itself re your queries and why a return to zonal is the form horse further ahead:

 

"...after a quasi-meridional period in approx the day 6 to 8 day f/c period in which a filling area of low pressure moves SE’wards across UK, there is a return thereafter to the generally zonal pattern already seen for most of this winter. There are differences between models.... wrt the detail of the return to a more zonal pattern, but very little disagreement that this broadscale evolution will occur.....

Examination of Shannon Entropy f/c output from both EC and MOGREPS both have low entropy / high confidence early in the 6-10 day period and later (in the trend period), with a spike of high entropy / low confidence around days 8 or 9, relating to

the detail of the return to zonal flow."

well we shall see but the models don't really seem to be showing a full on zonal onslaught tonight so could be a possibility that the met office 14dayer outlook changing if these types of output keep showing im not convinced although you guys have far more forecasting tools for your eyes only.

[fergieweather]

So regardless of how we get to day 10 from day 6 there is good agreement that a zonal flow will re-establish it's self across the British isles.

 

Correct - and I've just come of a conference with UKMO who remain confident on that ultimate outcome (and they aren't expecting any issues re lowland snow across southern England next week, as everything currently sits model-wise, but I think we'd all gathered that from the models ourselves). The rain issues, on the other hand, are top of the agenda. Tomorrow offers e.g. 10-15mm 30%PROB 20mm Somerset Levels; same area Sunday 15-25mm with to 35mm possible locally. EA have raised to Amber there too.

[Man With Beard]

gfs the azores ridge looks like our friend for once slowing the next low out of the states allowing a chance for better ridging and amplification of heights could be a stella run from the gfs.

 

as steve murr said lastnight knife edge 50/50.

 

But if the low stalls, rather than move through, too much mild will get injected from the south, which is what happens by T144, with uppers rising again across almost the whole of the UK. Hopefully the UKMO will keep them rattling through!

[MR EXTREMES]

gfs returning towards a stalemate again.

[Turnedoutniceagain]

Sorry for the commentary

 

UKMO 96 - Awsome

 

http://www.meteociel.fr/ukmo/runs/2014012312/UN96-21.GIF?23-17

 

Draw your eyes towards Southern Norway & the deep cold angle.....

 

S

 

Look at the USA on that one !!

[Cecil Hogmanay Melchett]

Not a great GFS12Z unfortunately.Very frustrating run esp with a 1045mb anticyclone sat to the North east...

[MR EXTREMES]

For 48 hours at the most, We really need some colder air to get mixed in if we wish to see some low level snow during this short cold snap!

yes but this is why I added the gfs progressive nature infact the gfs starts really well but then goes into over drive but the ukmo does not show this.

[The Eagle]

UKMO is ok but the writing is on the wall there for the atlantic breaking through

 

 

 

 

 

Close to GFS evolution in fact.

Edited January 23, 2014 by The Eagle

[SMU]

Correct - and I've just come of a conference with UKMO who remain confident on that ultimate outcome (and they aren't expecting any issues re lowland snow across southern England next week, as everything currently sits model-wise, but I think we'd all gathered that from the models ourselves). The rain issues, on the other hand, are top of the agenda. Tomorrow offers e.g. 10-15mm 30%PROB 20mm Somerset Levels; same area Sunday 15-25mm with to 35mm possible locally. EA have raised to Amber there too.

 

http://www.meteociel.fr/ukmo/runs/2014012312/UN144-21.GIF?23-17

UKMO raw 144-

 

Shows a battle of East meets west-

 

-28c Air moves into Europe & is primed to at least make it to Germany ( modified to -20) by 168-

 

Where as the atlantic train approaches the UK at 168 on the UKMO....

 

I think * there will be some discussion tonight about the extension of the cold post day 7 with less of a zonal theme, of course NW > SE zonal could be fruitfull....

 

UKMO Raw tonight is 9.5/10 if the ooz was 10/10.

Although troublesome snow for the SE if that verifies- not that it will at this range.

 

S

Edited January 23, 2014 by Steve Murr

[shaky]

I am waiting for that steve murr boom chart at t120 on the ukmo?

[swfc]

Slight downgrade on the ukmo at 144hrs and the gfs 12z looks poor once the low slips south east and we skip past our transient easterly.Looks a good call there by ian regarding the atlantic moving in

[frosty ground]

The UK@144 looks colder than the GFS at 144, but I fail to see where any low level snow will come from, the real cold air fails to arrive and even the UK model is starting to shunt the block away at 144. 

[MR EXTREMES]

This garbage winter is going to continue being garbage.

I think a professional like ian f post most likely does not aid us coldies with there views but one thing you can be sure of things are still very much in the balance its far from over.

 

although I respect ians formal input.

[R.P. McMurphy]

Correct - and I've just come of a conference with UKMO who remain confident on that ultimate outcome (and they aren't expecting any issues re lowland snow across southern England next week, as everything currently sits model-wise, but I think we'd all gathered that from the models ourselves). The rain issues, on the other hand, are top of the agenda. Tomorrow offers e.g. 10-15mm 30%PROB 20mm Somerset Levels; same area Sunday 15-25mm with to 35mm possible locally. EA have raised to Amber there too.

 

Hmmm.. How does one have high confidence circa 10 days in advance to a return of Zonal & no issues regards lowland snow, but a 30% probability of 10-15mm of rain for the next day?

 

I would take it with a pinch of salt re snow issues next week, especially amounts/quantities. I can count a lot of times the forecast has been "Little snow" and turned out to be quite a lot.

Edited January 23, 2014 by Glenn W

[Joe Levy]

Slight downgrade on the ukmo at 144hrs and the gfs 12z looks poor once the low slips south east and we skip past our transient easterly.Looks a good call there by ian regarding the atlantic moving in

Not really, it backs the pattern westwards and there's nothing wrong with that to be honest. It delays the arrival of the cold a bit, but gives us more room for error