Model output discussion - 7th January onwards

[Spah1]

8 minutes ago, knocker said:

Frankly, given the lack of agreement between the models, i think looking for detail vis snow 7-10 days down the road a pointless exercise; but hey what do I know..

More than most

[TEITS]

As many know I like to look at the Iceland SLP ensemble mean.

The mean at the end is now 1018mb with some members nearly hitting 1040mb.

Shall keep checking to see if the trend towards the Greenland High continues over the next few days.

 

[Catacol]

Got a bit of work to do so I'll disappear for a bit now - but I'll post this EPS anomaly for Weds 23rd here just as a finisher. 

2 things to note - building pressure to the N/NW as signposted by Lorenzo just now as a possibility - and a deepening of the Euro trough. Look also at the 500hpa flow lines to the north of the UK - becoming quite separated as pressure builds. This ties in with EC expectations as we move towards week 3 on that EC chart posted so many times recently, and increases the chances of a potent easterly element to the air flow by the time we get to 25th January or so. No sign of significant atlantic incursions - though the occasional stalling front would be handy so I hope the mid atlantic doesn't shut up shop completely. 

And what is the current and medium term forecast for Scandy and Central Europe? 

Here's the 850 hpa ANOMALY for eastern Europe and Scandy on Weds 23rd.

Running around 4 - 6 degrees below normal. Below normal. Normal is pretty cold out there at this time of year. 4 - 6 degrees less than that. 

I'll come back later. I'm very happy with the macro and microscale picture right now.

 

Edited January 13, 2019 by Catacol

[Frosty.]

Wonderful GEFS 6z mean in the mid / long term..becoming very cold with ice days for many and sharp frosts with plenty of snow potential as it looks mainly trough dominated...can't help getting excited by this!!

[karlos1983]

1 hour ago, feb1991blizzard said:

Just waiting for the ECM London graph to update.

Still waiting not good timing if we lose them again

[nick sussex]

Good of Catacol to bring up Feb 1996 and let me relive a very traumatic experience ! ! I’m suing for damages !

The infamous slider which slid off giving me three minutes of snow when I lived in Wimbledon ! In the meantime many western areas and indeed basically everywhere bar the east got plastered !

I remember vividly watching the BBC weather every bulletin to see if the damn precip was moving any further east . It just refused .

Anyway very enjoyable and informative posts Cat, thanks  , I’ll forgive the 1996 reminder !

[Kirkcaldy Weather]

Have I stumbled into a positive version of the model thread today?  Great stuff folks   some fantastic posts by all in here but special mentions to @Catacol and @Steve Murr for the in depth posts 

and why not be positive when the charts are looking as good as they are, this upcoming spell of weather is beginning to get a very wintry feel about it.

sliding lows beginning to shape up better too (still looking for some slight westwards adjustment and slightly lower pressure (aka not a hurricane strength GFS special) to give us the best chance at getting that initial feed of colder air / uppers) 

              @feb1991blizzard have you been sneaking into the GEFS servers and producing these runs, with the amount of stonkers that are appearing  

looking out the sledges and snow shovels is looking like a better idea as each day passes...  

ensemble ECMWF/IFS 0z 240h   ensemble NAEFS 0z 324h  and by the end   blocking anyone?  

ensembles GEM 0z

      

  

ensembles FNMOC/NOGAPS 0z 

    

  

 

[Bazray]

11 minutes ago, nick sussex said:

Good of Catacol to bring up Feb 1996 and let me relive a very traumatic experience ! ! I’m suing for damages !

The infamous slider which slid off giving me three minutes of snow when I lived in Wimbledon ! In the meantime many western areas and indeed basically everywhere bar the east got plastered !

I remember vividly watching the BBC weather every bulletin to see if the damn precip was moving any further east . It just refused .

Anyway very enjoyable and informative posts Cat, thanks  , I’ll forgive the 1996 reminder !

The slider slid off

[SMU]

Cheers @Kirkcaldy Weather

GFS 06z flatlining & theres still room for another 1/2 degrees from day 5/6....

[BLAST FROM THE PAST]

@Kirkcaldy Weather you missed Perturbation 6, my fav on 06z.  Storm force Easterly gale t 228 until t252........monumental.....

BFTP

Edited January 13, 2019 by BLAST FROM THE PAST

[johnholmes]

My take on the upcoming cold spell using the usual 500 mb anomaly charts

Looking at the latest upper air, 6-15 days from now. The usual 500 mb anomaly charts.

Not that they have been either consistent or a good guide at times but the three I use have been slowly converging over the past week into a more coherent and agreed pattern.

 

One item that has been consistent is the gradual lowering on all 3 of the contour heights. A week or so ago the heights just south of the UK with above 558 DM now they are predicted to be closer to 546DM or lower,

 

ECMWF-GFS

Today it is the turn of GFS to show the most meridional and cold pattern. Previously it had not had much in the way of this ridging over the western Atlantic into the Greenland area but now it does. Not sure if this will stay although judging by the EC and NOAA this is where it should be.

 

NOAA

Their 6-10 still shows a more Atlantic type of PM pattern with some ridging into Greenland, similar to how it has dealt with the pattern for about a week. +ve heights are shown off Newfoundland and these have also steadily increased over the last week on its daily output. Likewise the actual contour heights (just south of the UK) are showing at 546 DM some 10-12 DM down on earlier predictions. The 8-14 is a pretty similar chart in the pattern and positions of any ridging/troughing. Perhaps most of us might be more relaxed about this upcoming cold spell if these two charts from NOAA showed similar meridionality to EC/GFS. However, to me, the consistency of NOAA gives some confidence in the cold spell being something that is going to be there two weeks from now. How marked the cold will be, where any snow falls, is of course not for this type of chart but from the operational ones closer to T+00.

My own punt would be for a cold, sometimes very cold period of at least 2 weeks for most areas. Only temporary breaks in it for parts of the west and SW, unless a very active system breaks NE from the Atlantic. Then the usual problem of show or rain ahead and/or behind it. All full of interest for all those cold fans and for anyone with a weather interest.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

[Kirkcaldy Weather]

3 minutes ago, BLAST FROM THE PAST said:

@Kirkcaldy Weather you missed Perturbation 6, my fav on 06z.  Storm force Easterly gale t 228 until t252........monumental.....

BFTP

Apologies must have clicked ahead of that one without realizing, just for you the #winterofdiscontent run  think many of us would be digging out if a run like that came off 

    

[Bottled Snow]

10 minutes ago, johnholmes said:

My take on the upcoming cold spell using the usual 500 mb anomaly charts

Looking at the latest upper air, 6-15 days from now. The usual 500 mb anomaly charts.

Not that they have been either consistent or a good guide at times but the three I use have been slowly converging over the past week into a more coherent and agreed pattern.

 

One item that has been consistent is the gradual lowering on all 3 of the contour heights. A week or so ago the heights just south of the UK with above 558 DM now they are predicted to be closer to 546DM or lower,

 

ECMWF-GFS

Today it is the turn of GFS to show the most meridional and cold pattern. Previously it had not had much in the way of this ridging over the western Atlantic into the Greenland area but now it does. Not sure if this will stay although judging by the EC and NOAA this is where it should be.

 

NOAA

Their 6-10 still shows a more Atlantic type of PM pattern with some ridging into Greenland, similar to how it has dealt with the pattern for about a week. +ve heights are shown off Newfoundland and these have also steadily increased over the last week on its daily output. Likewise the actual contour heights (just south of the UK) are showing at 546 DM some 10-12 DM down on earlier predictions. The 8-14 is a pretty similar chart in the pattern and positions of any ridging/troughing. Perhaps most of us might be more relaxed about this upcoming cold spell if these two charts from NOAA showed similar meridionality to EC/GFS. However, to me, the consistency of NOAA gives some confidence in the cold spell being something that is going to be there two weeks from now. How marked the cold will be, where any snow falls, is of course not for this type of chart but from the operational ones closer to T+00.

My own punt would be for a cold, sometimes very cold period of at least 2 weeks for most areas. Only temporary breaks in it for parts of the west and SW, unless a very active system breaks NE from the Atlantic. Then the usual problem of show or rain ahead and/or behind it. All full of interest for all those cold fans and for anyone with a weather interest.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Thanks John...always wait to see your take on the anomoly charts before getting too excited prior to a possible  cold spell. ...hopefully the signal will continue to strengthen in future runs 

Edited January 13, 2019 by Bottled Snow

[sunnijim]

1 hour ago, nick sussex said:

Good of Catacol to bring up Feb 1996 and let me relive a very traumatic experience ! ! I’m suing for damages !

The infamous slider which slid off giving me three minutes of snow when I lived in Wimbledon ! In the meantime many western areas and indeed basically everywhere bar the east got plastered !

I remember vividly watching the BBC weather every bulletin to see if the damn precip was moving any further east . It just refused .

Anyway very enjoyable and informative posts Cat, thanks  , I’ll forgive the 1996 reminder !

Remember that well,of course nothing in Hastings,but work took me round the clockwise section of the M25 that day.

As I neared the Chessington Exit the Green and pleasant land changed.

I witnessed half the landscape North to South change  from Green to White,with a divide that was as etched onto the Winter landscape as if created by an artist's brush.

A memory that has stuck with me in particular was one farm field, half white and the other green,a frontal dividing line in the most incredible clarity.

Edited January 13, 2019 by sunnijim

[tight isobar]

1 hour ago, Catacol said:

Got a bit of work to do so I'll disappear for a bit now - but I'll post this EPS anomaly for Weds 23rd here just as a finisher. 

2 things to note - building pressure to the N/NW as signposted by Lorenzo just now as a possibility - and a deepening of the Euro trough. Look also at the 500hpa flow lines to the north of the UK - becoming quite separated as pressure builds. This ties in with EC expectations as we move towards week 3 on that EC chart posted so many times recently, and increases the chances of a potent easterly element to the air flow by the time we get to 25th January or so. No sign of significant atlantic incursions - though the occasional stalling front would be handy so I hope the mid atlantic doesn't shut up shop completely. 

And what is the current and medium term forecast for Scandy and Central Europe? 

Here's the 850 hpa ANOMALY for eastern Europe and Scandy on Weds 23rd.

Running around 4 - 6 degrees below normal. Below normal. Normal is pretty cold out there at this time of year. 4 - 6 degrees less than that. 

I'll come back later. I'm very happy with the macro and microscale picture right now.

 

Good stuff @Catacol..

The mac/micro both- now worth noting..

We-are at that stage...and alls looking very well indeed.

Winters coming...

The baby is up-n running!

[danm]

20 minutes ago, sunnijim said:

Remember that well,of course nothing in Hastings,but work took me round the clockwise section of the M25 that day.

As I neared the Chessington Exit the Green and pleasant land changed.

I witnessed half the landscape North to South from Green to White, a memory that has stuck with me in particular was one farm field, half white and the other green,a frontal dividing line in the most incredible clarity.

Without derailing the thread (although we’re in the quiet part of the day), also have memories of this even though I was only 10 years old in 1996. Nothing in my part of NE London. Yet the western edge of Greater London would have got quite a bit. Remember seeing the news with places out west getting pasted and us nothing. 

[Methuselah]

6 minutes ago, tight isobar said:

Good stuff @Catacol..

The mac/micro both- now worth noting..

We-are at that stage...and alls looking very well indeed.

Winters coming...

The baby is up-n running!

Well, one thing's for sure TI: my inner-toddler has been quite definitely tickled by all the eye-candy!

Edited January 13, 2019 by Ed Stone
Apostrophe crime committed!

[Man With Beard]

No time for an ecm ensembles watch yet - hopefully tonight - but these clusters at T300 show nicely the potential direction of travel once we hit the heart of the potential cold period

Cluster one (41%): Euro trough, minor Scandi ridge - cold, easterly and even potential for a quick beast from the east?

Cluster two (22%): Euro trough, Greenland/ Iceland high - good for repeated injections of cold from the north. 

Cluster three (22%): Euro trough but closer to the UK, mini Atlantic ridge, for this to be snowy (especially the south) the cold would already need to be in situ. Longevity questionable 

Cluster four (16%): Trough further north, milder air possibly into south, not out of the question that cold could return to all later on. 

Edited January 13, 2019 by Man With Beard

[Purga]

1 hour ago, karlos1983 said:

Still waiting not good timing if we lose them again

London EPS spreads showing a prolonged period of below -5 850hP after next Thursday.

All to play for

[aitchbomb]

5 minutes ago, tight isobar said:

Good stuff @Catacol..

The mac/micro both- now worth noting..

We-are at that stage...and alls looking very well indeed.

Winters coming...

The baby is up-n running!

Up and sucking innit?

[Djdazzle]

Are we going to get a stonking set of 12z runs? Have to say that I’m becoming cautiously optimistic! Hope the Euro’s don’t backtrack now that the GFS has moved towards them.

[shaky]

Slide icon slide

[seabreeze86]

5 minutes ago, shaky said:

Slide icon slide

It's having a go shaky crazy difference from the 0z run of the ICON,  under it goes

Edited January 13, 2019 by seabreeze86

[shaky]

2 minutes ago, seabreeze86 said:

It's having a go shaky crazy difference from the 0z run of the ICON 

It actually goes the full wack and slides

[northwestsnow]

4 minutes ago, shaky said:

It actually goes the full wack and slides

Are you sure mate?