Model Output Discussions 06z 04/11/16

[karlos1983]

28 minutes ago, Frosty. said:

There are already early weather warnings in force for higher parts of central and northern uk for snow and you can see why that's the case going by these Gfs 6z charts which show quite a few hours worth of snow with elevation and don't be surprised if some descends to lower levels..the interior of scotland is in line for a spell of heavy snow higher up and looking at the midweek temps shows an early taste of winter, the first salvo of hopefully many cold and wintry spells during the next 4 months or so!

I know this is only a northern event but it's very worthy of discussion. 

 

Certainly is nice to see Frosty, like you say hopefully the first of many. Nice graphic display of how, when, where and how much. Just goes to show what a difference it makes once you've got the cold in so to speak. As always nicely backed up by charts Karl.

Edited November 7, 2016 by karlos1983

[Downburst]

The CFS Week 3 Mean MAX temp Chart shows a marked cool down from 21 Nov to 27 - not too far out and in line with some FI charts. Even more interesting is the charts for December, showing mid December mean soil temps likely to have some heavy frosts and periods of ice days.  Certainly signs of a cold end of November and extended into December. I know it's the CFS but the whole of December is looking cold http://www.weatherweb.net/wxwebchartscfs1ukavmaxweek.php?chart=cfs1es4avsoiltempukweek7.gif

 

[karlos1983]

5 minutes ago, Downburst said:

The CFS Week 3 Mean MAX temp Chart shows a marked cool down from 21 Nov to 27 - not too far out and in line with some FI charts. Even more interesting is the charts for December, showing mid December mean soil temps likely to have some heavy frosts and periods of ice days.  Certainly signs of a cold end of November and extended into December. I know it's the CFS but the whole of December is looking cold http://www.weatherweb.net/wxwebchartscfs1ukavmaxweek.php?chart=cfs1es4avsoiltempukweek7.gif

 

I thought that was quite impressive (low) soil temps, but actually not far off current values

 

[andymusic]

GFS is still making ever so tiny corrections westward with this front even down to the wire - not sure it'll make much difference but it's very noticeable

[Mucka]

Nice to see the forum in good spirits and ramping up on a chilly start to the new week.

After an uninspiring 18z ensemble set last night the FI Operational output this morning has shown some of the wintry promise that has long been discussed here for second half of November.

The big picture though was always for a deep trough to dig into the mid latitudes toward mid month but where this sets up and how amplified the upstream pattern will become are still very much up for grabs.

At least some of the mid term fog is lifting and the way forward is slowly coming into focus .

It has been the best Autumn model watch for some years, now bring on the winter.   

Edited November 7, 2016 by Mucka

[Downburst]

Just now, karlos1983 said:

I thought that was quite impressive (low) soil temps, but actually not far off current values

 

My Chart showed the air temp, not the Soil Temp. I just referred to the Soil temp for December, but didn't show it as it is the CFS and is not meant to be taken literally, but watched over time. But for the hell of it here is the CFS Member 1 Ensemble Mean for December , week ending 18th as a sample.

[karlos1983]

1 minute ago, Downburst said:

My Chart showed the air temp, not the Soil Temp. I just referred to the Soil temp for December, but didn't show it as it is the CFS and is not meant to be taken literally, but watched over time. But for the hell of it here is the CFS Member 1 Ensemble Mean for December , week ending 18th as a sample.

Yeah the link was what I was referring too. At least its not showing soil temps of 10 degrees and soggy 

[fergieweather]

21 minutes ago, Downburst said:

The CFS Week 3 Mean MAX temp Chart shows a marked cool down from 21 Nov to 27 - not too far out and in line with some FI charts. Even more interesting is the charts for December, showing mid December mean soil temps likely to have some heavy frosts and periods of ice days.  Certainly signs of a cold end of November and extended into December. I know it's the CFS but the whole of December is looking cold http://www.weatherweb.net/wxwebchartscfs1ukavmaxweek.php?chart=cfs1es4avsoiltempukweek7.gif

 

Indeed. It'll be interesting seeing how ECMWF Seasonal output tomorrow (and for that matter, EC Monthly this evening) handle prospects as we crossover into December, versus CFS (albeit that product doesn't receive the same weighting in UKMO seasonal assessment as GloSea, ECMWF and MeteoFrance-Climate) and what sort of parallel exists with them all, or not. GloSea continues it's path to resurrect the blocked theme later November and on through December... whilst the signal for an extraordinarily weak stratospheric PV remains an underpinning and noteworthy theme. Given how well the model has synthesised developments 'up aloft' since September, it does lean to fair confidence in how this now unfolds, at least in the broadest sense. 2nd half of winter could well be in a different 'mode' to the 1st, but let's see how Part 1 gets on.

Edited November 7, 2016 by fergieweather

[shaky]

10 minutes ago, andymusic said:

GFS is still making ever so tiny corrections westward with this front even down to the wire - not sure it'll make much difference but it's very noticeable

You are right mate!!same with euro4 and arpege which is why more of the north and east midlands could see some snow!!hopefully another correction west on the 12z gfs and it makes it a bit more interesting!!ian fergie should shed a bit more light on this situation later!!

[blizzard81]

32 minutes ago, fergieweather said:

Indeed. It'll be interesting seeing how ECMWF Seasonal output tomorrow (and for that matter, EC Monthly this evening) handle prospects as we crossover into December, versus CFS (albeit that product doesn't receive the same weighting in UKMO seasonal assessment as GloSea, ECMWF and MeteoFrance-Climate) and what sort of parallel exists with them all, or not. GloSea continues it's path to resurrect the blocked theme later November and on through December... whilst the signal for an extraordinarily weak stratospheric PV remains an underpinning and noteworthy theme. Given how well the model has synthesised developments 'up aloft' since September, it does lean to fair confidence in how this now unfolds, at least in the broadest sense. 2nd half of winter could well be in a different 'mode' to the 1st, but let's see how Part 1 gets on.

Good news for the coldies Ian. Just a quick question if you don't mind. When does the November update for the met office global probability maps become available? I was expecting it today but it is still showing October's.

[fergieweather]

8 minutes ago, blizzard81 said:

When does the November update for the met office global probability maps become available? I was expecting it today but it is still showing October's.

Normally around the 10th of each month. Like the Contingency Planner document, there's no 'set' date as such.

[andymusic]

and out comes the 12z gfs and once again a tiny move west again and the front is delayed - all credit to Mr. Murr

[Ali1977]

I like the sound of the weak PV looking like staying on into Atleast Dec, personally a front loaded Winter is better than rear as by March I'm ready for some heat. I'm not sure what the 2nd half looks like at the minute but different "mode" as Ian puts in I guess could mean anything - and of course could change given the timescales.

A few more runs like the last few and we may start being able to put some confidence on a blocking theme appearing just after mid month, still expect some big differences between models runs though. 

[Summer Sun]

The NAO does look like going negative again around mid-month might not be for too long with hints of a rise again soon after

[Ali1977]

Another good day 10 chart with zero PV and heights to our NW. Looking great for a fun few weeks on this forum. 

Gem loaded with potential too, WAA into greenland which "could" link with the heights in heart of the Pole if we skipped forward a few days.

I think it's key not too look and any particular chart as gospel at day 10 , but more the bigger picture. At day 10 anything could happen, but looking at the charts, that anything isn't going to be a bad thing for the coldies among us.

Edited November 7, 2016 by Ali1977

[Methuselah]

Come on guys, you're giving me flashbacks...If my memory serves, the lunchtime forecast, on December 27 1962, was: 'mostly cloudy with a chance of some light snow at times, temps of -3 or -4'?

Or is all this model-related optimism addling my brain?

[A.J]

hmm....In house NMM rather downplays the snow signals in the short term for the vast majority of the UK....dewpoints the wrong side of marginal for most, leaving only  The Penines the Southern Uplands of Scotland & naturally highland Scotland in the firing line, most of N England and the central belt of Scotland seeing a cold rain or rain/sleet mix....certainly different to the Euro 4 hi-res output for the same time period which has wintry ppn as far south as the Peak District and not exclusively (but mainly) to high ground.....which one will be right?

[Cheshire Freeze]

3 minutes ago, ajpoolshark said:

hmm....In house NMM rather downplays the snow signals in the short term for the vast majority of the UK....dewpoints the wrong side of marginal for most, leaving only  The Penines the Southern Uplands of Scotland & naturally highland Scotland in the firing line, most of N England and the central belt of Scotland seeing a cold rain or rain/sleet mix....certainly different to the Euro 4 hi-res output for the same time period which has wintry ppn as far south as the Peak District and not exclusively (but mainly) to high ground.....which one will be right?

Risk seems to have diminished somewhat on latest Euro4 output

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/11/07/basis12/ukuk/prty/16110900_0712.gif

 

[northwestsnow]

A rather poor GFS this afternoon with a very active jet - looks very different to UKMO at 144 though so hopefully ukmo will be closer to the mark!

http://old.wetterzentrale.de/pics/Rukm1441.html

GFS much flatter ..

[andymusic]

5 minutes ago, CreweCold said:

Risk seems to have diminished somewhat on latest Euro4 output

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/11/07/basis12/ukuk/prty/16110900_0712.gif

 

Euro 4 is showing potential falls for quite a bit of the east midlands around 6am - peak cold hour - the beeb are going for that too

euro 4 12z

Edited November 7, 2016 by andymusic

[Cheshire Freeze]

Just now, andymusic said:

Euro 4 is showing potential falls for quite a bit of the east midlands around 6am - peak cold hour - the beeb are going for that too

Hmm I'm not convinced

What I get from this is a few CMs over higher ground

 

[Smiler1709]

2 minutes ago, northwestsnow said:

A rather poor GFS this afternoon with a very active jet - looks very different to UKMO at 144 though so hopefully ukmo will be closer to the mark!

http://old.wetterzentrale.de/pics/Rukm1441.html

GFS much flatter ..

Actually looks good to me, it's not about the here and now it's what lies ahead, there's no reason why the Azores high couldn't link with the Scandinavian high, the theme continues, blocked, dry and no sign of the Atlantic. 

[weirpig]

2 minutes ago, andymusic said:

Euro 4 is showing potential falls for quite a bit of the east midlands around 6am - peak cold hour - the beeb are going for that too

It is quite a upgrade for the midlands more westerly as well 

[northwestsnow]

1 minute ago, Smiler1709 said:

Actually looks good to me, it's not about the here and now it's what lies ahead, there's no reason why the Azores high couldn't link with the Scandinavian high, the theme continues, blocked, dry and no sign of the Atlantic. 

Sorry i think my post might have been a bit 'back to front', i prefer the ukmo run to GFS

http://old.wetterzentrale.de/pics/Rukm1441.html

[Cheshire Freeze]

Just now, weirpig said:

It is quite a upgrade for the midlands more westerly as well 

Don't fall into the trap of seeing pink colours and thinking 'oh, snow'. We see this time and again from the EURO4. If we look at the corresponding precipitation for 6AM there is barely any over most of central and west Mids at that time

Places like the Lincs Wolds and southern and eastern peaks may do OK for a few cm though.