Model output discussion - 5th December 2016 - Into Winter we go

[Methuselah]

27 minutes ago, Frosty. said:

Have I stumbled into the moaning thread?

There is nothing we can do about what the models are showing, it is what it is so just accept it!

And, whilst the models do their thing, the great British weather be doing something else altogether!

[Summer Sun]

 

[fergieweather]

3 minutes ago, Tim Bland said:

Hopefully this is what Ian Means by "High west of Ireland"... I suspect he means a bit closer to Ireland than that though !? 

Yes but it's something of a magical mystery tour. Monday’s EC Monthly offered rather uninspiring anomalies on face value, but masked a whole raft of spread from individual ENS stamps. It's understandable why UKMO continue to mention some risk of colder (N/NW'ly) synoptics manifesting into first half of Jan, but the most likely direction of travel is an imponderable at present.

[Frosty.]

Yes christmas day looks very yellow again this year, with a hint of orange and green.. what a surprise huh

Edited December 21, 2016 by Frosty.

[Ali1977]

15 minutes ago, fergieweather said:

Yes but it's something of a magical mystery tour. Monday’s EC Monthly offered rather uninspiring anomalies on face value, but masked a whole raft of spread from individual ENS stamps. It's understandable why UKMO continue to mention some risk of colder (N/NW'ly) synoptics manifesting into first half of Jan, but the most likely direction of travel is an imponderable at present.

It's just so hard to get decent set ups in the UK during winter, some decent short cold snaps possible within the ENS but nothing jumping out as prolonged on the latest set. I hope we aren't waiting till March again, ice days and long lasting lying snow is most possible in Jan so lets hope we get lucky !!

[Interitus]

46 minutes ago, Summer Sun said:

Christmas day sees the windier conditions transfer to England and Wales though nothing unusual for the time of year

Yes if you look at charts from a couple of days ago, the shortwave forms a deep low to the north of Scotland 

on the northern side of the jet

and engages stratospheric air with a low tropopause / tropopause fold

fortunately now shortwave doesn't really develop 'til it passes to the east of the UK

as it stays to the south of the jet across the Atlantic which is now expected to be further north

and the low pressure encounters the low level stratospheric air later, further east

[gottolovethisweather]

1 hour ago, fergieweather said:

Latest DECIDER products lean to increased risk of NW'ly flow early into New Year; equal chances of high cell being centred over France or W of Ireland by that stage. 

 

 

 

So in other words, BLOCKED to the West of us, BLOCKED to the East of us, STUCK IN THE MIDDLE OF YOU. 

Wow, a song from the year I was born. Happy Christmas everyone. I quite like the battleground atmospheric stagnation in the model outputs post-Christmas because it makes us deliberate what might come about as we enter the New Year, something we'll be debating over for days no doubt. 

Edited December 21, 2016 by gottolovethisweather

[knocker]

12 minutes ago, Interitus said:

Yes if you look at charts from a couple of days ago, the shortwave forms a deep low to the north of Scotland 

on the northern side of the jet

and engages stratospheric air with a low tropopause / tropopause fold

 

fortunately now shortwave doesn't really develop 'til it passes to the east of the UK

as it stays to the south of the jet across the Atlantic which is now expected to be further north

and the low pressure encounters the low level stratospheric air later, further east

Interitus I thought I'd mention this in case you are not but I assume you are familiar with Alicia Bentley's site where she has a great selection of real time GFS charts

http://www.atmos.albany.edu/student/abentley/realtime.html

[legritter]

Must be very hard to say what the synoptic situation will be come early January, at ten days away that's ages in meteorological time .Also bearing in mind that the upper atmosphere at this moment could be cooking something up ,even in this modern day the amount of data collected is minimal even with sattelite and computers ,our only hope from current pattern is time IF you want some magical white stuff and ice days , looking very likely that the Atlantic could slow down so let's hope any high pressure can establish in the right position ,another straw clutch for me is the fact that the euro slug as been king for a while ,let's hope a new king comes to power , thanks to Fergie weather for his input into our top weather forum ,cheers .

[Interitus]

9 minutes ago, knocker said:

Interitus I thought I'd mention this in case you are not but I assume you are familiar with Alicia Bentley's site where she has a great selection of real time GFS charts

http://www.atmos.albany.edu/student/abentley/realtime.html

Yes, good site that thanks. Also I realised that it might seem that I overemphasised the low tropopause, when being south of jet would reduce divergence aloft and cyclogenesis, but I was more interested in the explosive cyclogenesis that the high pv (potential vorticity) stratospheric air encourages.

[mountain shadow]

5 minutes ago, legritter said:

Must be very hard to say what the synoptic situation will be come early January, at ten days away that's ages in meteorological time .

I disagree, it is very easy to say what it will be. A mid latitude block centred around the UK with the jet running over the top.

[Frosty.]

3 minutes ago, mountain shadow said:

I disagree, it is very easy to say what it will be. A mid latitude block centred around the UK with the jet running over the top.

I disagree, it's not easy to say for sure the actual weather come the first week of January.

Edited December 21, 2016 by Frosty.

[gottolovethisweather]

29 minutes ago, legritter said:

Must be very hard to say what the synoptic situation will be come early January, at ten days away that's ages in meteorological time .Also bearing in mind that the upper atmosphere at this moment could be cooking something up ,even in this modern day the amount of data collected is minimal even with sattelite and computers ,our only hope from current pattern is time IF you want some magical white stuff and ice days , looking very likely that the Atlantic could slow down so let's hope any high pressure can establish in the right position ,another straw clutch for me is the fact that the euro slug as been king for a while ,let's hope a new king comes to power , thanks to Fergie weather for his input into our top weather forum ,cheers .

 

 

Yes indeed Legritter, I think some cold days ahead as we close out the year, a tad deja vu, but I'm not bothered, dry, frosty by night, chance of ice days all suggest it'll be fantastic for walks out in the countryside. 

Edited December 21, 2016 by gottolovethisweather

[gottolovethisweather]

11 minutes ago, Snowmut said:

Don't worry Bing's got this covered aswell!! 

It will snow again,there will be grit shortages,impassable roads,school,airport closures,etc etc....but when,we don't know..but everyday is a day closer!!

Merry Xmas 

 

 

What have I started, lol. YouTube videos everywhere. 

Quietly yet quickly attempts to dig out a blocked scenario development, this from the overnight ECM 0z at t+168 hours (28th December).

 

A doodle showing the hoped for "stuck in the middle with you" blocked scenario, not one that is currently on the cards, but COULD yet develop as the NWP outputs play about with all such possibilities over the coming days.

Edited December 21, 2016 by gottolovethisweather

[NeilN]

It's bizzare how Christmas Day is rather mild, yet around it it's average / seasonal! I've never known anything like that. I think this is going to be a winter that will catch us off guard and I reckon it looks promising reading the models for the start of 2017. 

[Nick F]

43 minutes ago, legritter said:

Must be very hard to say what the synoptic situation will be come early January, at ten days away that's ages in meteorological time .Also bearing in mind that the upper atmosphere at this moment could be cooking something up ,even in this modern day the amount of data collected is minimal even with sattelite and computers ,our only hope from current pattern is time IF you want some magical white stuff and ice days , looking very likely that the Atlantic could slow down so let's hope any high pressure can establish in the right position ,another straw clutch for me is the fact that the euro slug as been king for a while ,let's hope a new king comes to power , thanks to Fergie weather for his input into our top weather forum ,cheers .

Hard to be sure for sure, though we can only go on what the ensembles are hinting at. GEFS and EPS suggesting a return of the Gulf of Alaska ridge in early Jan, which would perhaps ridge far enough to the pole to temporarily turn the AO -ve. Also both signal the 'euro slug' ridge retrograding into the N Atlantic.

06z GEFS 500mb mean in early Jan

00z EC ensemble clusters likewise:

 

[Grimsby Snow Lover]

35 minutes ago, Nick F said:

Hard to be sure for sure, though we can only go on what the ensembles are hinting at. GEFS and EPS suggesting a return of the Gulf of Alaska ridge in early Jan, which would perhaps ridge far enough to the pole to temporarily turn the AO -ve. Also both signal the 'euro slug' ridge retrograding into the N Atlantic.

06z GEFS 500mb mean in early Jan

00z EC ensemble clusters likewise:

 

Could someone please explain this tweet as I have no idea what it's benefits could be. Thanks.

[Summer Sun]

 

[weather_it_will]

If we can get this Atlantic block in the new year, then it could kick off the start to something more winter like.

 

[Nick F]

21 minutes ago, Grimsby Snow Lover said:

Could someone please explain this tweet as I have no idea what it's benefits could be. Thanks.

Basically the Gulf of Alaska ridge may turn the Arctic Oscillation negative if it ridges to the pole and thus push cold air equatorward across N America and perhaps NE Europe. Though it may be a temporary feature, given the forecast strength of the polar vortex. Also note in the EC ens map the ridge over the N Atlantic which would suggest a NWly flow - as Ian F suggested earlier.

[knocker]

27 minutes ago, Nick F said:

Basically the Gulf of Alaska ridge may turn the Arctic Oscillation negative if it ridges to the pole and thus push cold air equatorward across N America and perhaps NE Europe. Though it may be a temporary feature, given the forecast strength of the polar vortex. Also note in the EC ens map the ridge over the N Atlantic which would suggest a NWly flow - as Ian F suggested earlier.

Equally this could just mean the surface high located just to the south west and then the upper flow backing W as it slips south as indicated by the means.

[Man With Beard]

Might be a little late on this but noticed the ECM mean ridge slightly back in the Atlantic today, and believe it or not this is their coldest D15 850s chart of the season 

 

 

[Frosty.]

10 minutes ago, knocker said:

Equally this could just mean the surface high located just to the south west and then the upper flow backing W as it slips south as indicated by the means.

I'm sure that would suit Sidney but most of us would like to see a potent NWly arrive during early January..fingers crossed.

Edited December 21, 2016 by Frosty.

[Don]

Just now, Frosty. said:

I'm sure that would suit Sidney but most of us would like to see a potent NWly to arrive during early January..fingers crossed.

Likely to deliver diddly squat down here but better than a south westerly I suppose.

[feno13]

8 minutes ago, Frosty. said:

I'm sure that would suit Sidney but us in the North West would like to see a potent NWly arrive during early January..fingers crossed.

Edited your post