Model Output Discussions 12z 01/09/2016

[BLAST FROM THE PAST]

3 minutes ago, carinthian said:

Not seen this early extensive cover of snow for a long time ( forecast date 10TH November 2016). Quite a significant depth throughout the heart of Russia and even snow cover as far west as Dutch/ North German border. All as a result of the persistent Northern Blocking and no length of zonal blasting.  Warms the cockles of your heart !

 C

The tenacity of this is something to behold.  Indeed large swathes of the landmass to our East has had a very cold October with rapid snow gain.  More of the same please

[jvenge]

4 minutes ago, BLAST FROM THE PAST said:

The tenacity of this is something to behold.  Indeed large swathes of the landmass to our East has had a very cold October with rapid snow gain.  More of the same please

Indeed. What will be interesting is if the western parts can keep the snow cover into the mid November or end of November range. Snow is still vulnerable to melting in the western parts and wouldn't take much to get it melting.

[summer blizzard]

GFS0Z was a thing of true beauty in FI. The easterly initially starts off dragging in warm air but starts pulling it in before a northerly arrives.

[bluearmy]

2 hours ago, BLAST FROM THE PAST said:

The tenacity of this is something to behold.  Indeed large swathes of the landmass to our East has had a very cold October with rapid snow gain.  More of the same please

Assume you mean well to our east Fred ?  The filling in due to occur closer to home once we get into next week over scandi and west russia/Eastern Europe.

wouldnt expect any south scandi/e European  snow cover to survive November intact though. 

Hopefully w Russia and n scandi can do so 

[ALL ABOARD]

Oh Polar Vortex where art thou?

The lack of any reformation is becoming more and more evident. GFS is in no hurry to see a westerly regime return.

[Ali1977]

GFS 06z is quite similar at day 9 to the 00z, E/NE wind should be inbound by day 11 if this follows the last run.  PV is less evident too so it could be a good FI, and with Scandy in the freezer it won't take too long to tap into  the cold if we get a N/Easterly.

Edited October 27, 2016 by Ali1977

[Zakos]

GFS 00Z (left) 06Z (right) at +144 hours. Note the huge differences over Alaska and Canada. whereas the rest of the hemisphere is mostly the same on both runs. I think it was Ian Ferguson who said the models are struggling with this region currently.

Pointless speculating about what will happen until this disparity is resolved IMO.

Fast forward to +180 hours and you can see the effect of this model disparity. 

Looking at the pattern over the Atlantic and Europe, there isn't a great deal of difference.

But over Canada, there is a marked difference in the output, which much more WAA on the 06z entering the Canadian arctic.

At + 222 hours, we have much stronger blocking in the Atlantic,  and far more WAA into the Canadian arctic,  almost completely removing the low heights from the region.

The models will continue to flip flop like this, as even small differences early on will have huge differences in the output down the line

It is pointless IMO looking at the output beyond 180 hours, though it has to be said the trend is towards a colder pattern for the UK.

Edited October 27, 2016 by Zakos

[Ali1977]

The NH looks crazy, this is very different and surely a chance of an early wintery outbreak as we move through Nov and beyond. The METO must be looking at this, not necessarily to issue a forecast, just thinking where on earth does this lead us.  Could turn into nothing, but I expect this forum is going to have a good few months coming up - be nice to see 1000 people online by late Nov like in 2010.

[Zakos]

4 minutes ago, Ali1977 said:

The NH looks crazy, this is very different and surely a chance of an early wintery outbreak as we move through Nov and beyond. The METO must be looking at this, not necessarily to issue a forecast, just thinking where on earth does this lead us.  Could turn into nothing, but I expect this forum is going to have a good few months coming up - be nice to see 1000 people online by late Nov like in 2010.

Agreed.

I am not an expert, but from my knowledge I would struggle to draw a better chart for long term cold potential for the UK.

The pattern we are forecast to enter is the polar opposite of what we were seeing this time last year.

The block this year is situated in the perfect spot,  right where we dont want the PV to set up.

I personally believe that we are entering a potent and long lasting cold spell. Whilst we cannot guarantee deep cold for the UK, the theme of stubborn northern blocking refuses to budge from the model output, not even the in the depths of FI.

 

 

 

 

 

[phil nw.]

Looking at the N.hemisphere the distribution of cold and warm is quite notable-day 5 ECM mean chart

The main residence currently of the pv is over Siberia-the new cold pole if you like.

Arctic Canada  unusually warm with little sign of the usual Greenland/Canada pv segment settling there at the moment.This all underlines the picture of a weak Atlantic jet-prone to fragmenting under the current regime over the Arctic.

 

Edited October 27, 2016 by phil nw.

[Seasonality]

2 hours ago, carinthian said:

Not seen this early extensive cover of snow for a long time ( forecast date 10TH November 2016). Quite a significant depth throughout the heart of Russia and even snow cover as far west as Dutch/ North German border. All as a result of the persistent Northern Blocking and no length of zonal blasting.  Warms the cockles of your heart !

 C

Very nice chart there Carinthian, most of Poland with a dusting and a big swathe of Northern Germany through to Denmark. Truly a sight to behold so early in the season. Snowfall shown well here.

 

[Frosty.]

The Gfs 6z shows reload after reload of cold air from the northwest / north from next week onwards which for a coldie is very good to see.

[Ali1977]

Support is growing in the GEFS for a more potent block in the Greenland /Labrodor area.  It has potential to be quite a big block that looks like it could be hard to move once in place, especially without anything to push it away to the East or S/East.  Bonfire night could be when things start getting colder (nothing unusual though) with some frosts,   however  NE europe is going to have an early taste of some seriously cold weather for this time of year.  

Edited October 27, 2016 by Ali1977

[legritter]

16 minutes ago, Frosty. said:

The Gfs 6z shows reload after reload of cold air from the northwest / north from next week onwards which for a coldie is very good to see.

Yes frosty Gfs showing some interesting Charts into November , Looking forward to tonights ECM MET of updates as if its out there next week we should start to see some firming up ,but i do expect a bit of flipping from run to run .I,m eagerly awaiting todays 16 day update from Met office also ,although we dont get to see any of their charts for this range at least we can read between the lines .Interesting northern profile at the moment ,seems to be quiet across the Pond , lets hope any cold air bottling up can be ejected south somewhere ,but with us weather enthusiasts lets hope it arrives not too early , Interesting times ahead i feel ,I may watch tonights runs from behind Sofa With A Cool STella and sausage bap ,.

[Frosty.]

The GEFS 6z mean looks anticyclonic for the most part throughout the next few weeks with very limited trough activity. Temperature wise, it's mild into early next week but then slowly trending cooler but nothing dramatic is indicated according to this..in fact, longer term the temps recover again from the south / southwest.

Edited October 27, 2016 by Frosty.

[jvenge]

GFS 6z ensembles look all over the place after T144. More runs, please :-)

[weirpig]

2 minutes ago, jvenge said:

GFS 6z ensembles look all over the place after T144. More runs, please :-)

Yep as Zakos as pointed out above   as long as the differences over Canada continue.  then i expect many solutions to be on the table.   Fun model watching though.

[feb1991blizzard]

7 minutes ago, jvenge said:

GFS 6z ensembles look all over the place after T144. More runs, please :-)

They look very tightly grouped on the 850hpa temperature graph right the way until the end.

[Frosty.]

Taking a snapshot at T+168 hours on the GEFS 6z mean / perturbations, one word, no actually two words spring to mind..benign / anticyclonic with nothing sinister lurking in the woodshed!

[jvenge]

21 minutes ago, feb1991blizzard said:

They look very tightly grouped on the 850hpa temperature graph right the way until the end.

Admittedly I looked at 2m and I also don't look at the UK, but a quick look at 850 for the UK shows quite a mix in itself. A bigger selection than from the 0z. 

[feb1991blizzard]

Just now, jvenge said:

Admittedly I looked at 2m and I also don't look at the UK, but a quick look at 850 for the UK shows quite a mix in itself. A bigger selection than from the 0z. 

 

Just now, jvenge said:

Admittedly I looked at 2m and I also don't look at the UK, but a quick look at 850 for the UK shows quite a mix in itself. A bigger selection than from the 0z. 

Admittedly I haven't been through them individually (which is the best method), but I hazard a guess that they only have slight variations in the shortwave pattern and that most have blocking to some extent throughout much of the run.

[jvenge]

2 minutes ago, feb1991blizzard said:

 

Admittedly I haven't been through them individually (which is the best method), but I hazard a guess that they only have slight variations in the shortwave pattern and that most have blocking to some extent throughout much of the run.

Oh indeed, I was more saying the end result on the ground scattered a lot from the 0z. My preferred method of looking is to see when the ensembles start broad temperature agreement

[Mucka]

2 hours ago, Zakos said:

GFS 00Z (left) 06Z (right) at +144 hours. Note the huge differences over Alaska and Canada. whereas the rest of the hemisphere is mostly the same on both runs. I think it was Ian Ferguson who said the models are struggling with this region currently.

Pointless speculating about what will happen until this disparity is resolved IMO.

Fast forward to +180 hours and you can see the effect of this model disparity. 

Looking at the pattern over the Atlantic and Europe, there isn't a great deal of difference.

But over Canada, there is a marked difference in the output, which much more WAA on the 06z entering the Canadian arctic.

At + 222 hours, we have much stronger blocking in the Atlantic,  and far more WAA into the Canadian arctic,  almost completely removing the low heights from the region.

The models will continue to flip flop like this, as even small differences early on will have huge differences in the output down the line

It is pointless IMO looking at the output beyond 180 hours, though it has to be said the trend is towards a colder pattern for the UK.

 

 

It is specifically the forming Atlantic trough seen here way off to our W/NW

And the exiting Canadian trough (seen here just N of the Atlantic trough) that are causing upstream shenanigans 

 

The GFS 18z (last night) and this mornings 00z did not phase them and kept the Atlantic sector more amplified and this mornings ECM moved toward that solution so it looke dlike a trend but this mornings 06z has somewhat reverted back to phasing these troughs

00z/06z comparison.

Obviously the strength of the Atlantic ridge and whether we caan block off energy pushing East over the block South of Greenland affects how amplified and far west the pattern is in FI.

Since this reflected throughout the ensemble suit it makes a marked difference between the 00z and 06z ensemble suits FI predictions. (Comparison below)

 

I have no idea whether GFS will stick with this through this afternoon and evening or if it is just a bit of a rogue run going against the current trend.

Plenty more upstream shenanigans ahead seems probable though so we are likely to see fairly strong divergence between runs and models from day 7/8 let alone FI proper.

All makes for fascinating model watching and it is easy to forget it is still only October.

 

 

 

 

 

[Frosty.]

Looking further into November, the GEFS 6z perturbations show more potential for coldies with polar / arctic maritime outbreaks and a few other close shaves with something more wintry..it's interesting to note the MO update hasn't really changed and still indicates predominantly NWly / Nly airflow from around next midweek or thereabouts onwards through most of November actually with no sign of the usual flat mild zonality, indeed temps are currently expected to become below average for most of the month ahead!

Edited October 27, 2016 by Frosty.

[BLAST FROM THE PAST]

5 hours ago, bluearmy said:

Assume you mean well to our east Fred ?  The filling in due to occur closer to home once we get into next week over scandi and west russia/Eastern Europe.

wouldnt expect any south scandi/e European  snow cover to survive November intact though. 

Hopefully w Russia and n scandi can do so 

Correct mate, anticipate westward advance to Scandi and Parts of Europe early Nov

Edited October 27, 2016 by BLAST FROM THE PAST