Model Output Discussion - Deeper into Autumn

[andy989]

10 minutes ago, tight isobar said:

This is IMO mirror -reflecting formats.. And a classic NH rounding MT , switch the Synoptics to opposing outs!.. ie height and vortex formation into opposite current syncs... I hope- And highly suspect I’ll be able to Elaborate  on this preety soon!current momentum is not being aligned via modelling!!!

 

 

[IDO]

The GFS 12z op is a solid cold chart, and as others say, get the cold in first, then the snow:

The parallel is not good, a rinse and repeat of what we have just seen, with cold kept just to our east and the UK at the end of the Atlantic train:

Bearing in mind this is a recurring theme, then another option we cannot ignore. Hopefully not...

[tight isobar]

2 minutes ago, andy989 said:

 

 

Sort of

[Ali1977]

Epic run really, nothing particularly cold but the longevity of an easterly which looks like becoming a northerly/Greenland hp in deep FI is notable - surface temp would be cold you’d think!! 
Let’s hope we keep upping the auntie on a cold spell, a nice cold Dec would be great - albeit not fit the heating bills!! 

Edited November 21, 2022 by Ali1977

[Mike Poole]

7 minutes ago, tight isobar said:

This !!

Think it will turn into this?

The complete switch of the PV is the gold at the end of the rainbow…

[tight isobar]

1 minute ago, Mike Poole said:

Think it will turn into this?

The complete switch of the PV is the gold at the end of the rainbow…

exactly - 

Edited November 21, 2022 by tight isobar

[minus10]

2 minutes ago, tight isobar said:

exactly - 

 

4 minutes ago, Mike Poole said:

Think it will turn into this?

The complete switch of the PV is the gold at the end of the rainbow…

Er...kind of feel drunk looking at that image Mike?

[Cheshire Freeze]

PV tapping out by the end of the run

[Frostbite80]

Typically the NE USA goes into the freezer while we end up with coldrain in FI 

Edited November 21, 2022 by Frostbite80

[January Snowstorm]

I thought yesterday we were saying the parallel was the model to use as its the new one??

[Kirkcaldy Weather]

Clear split in the TPV lobes on the 12z gfs run 

Also if there's concerns around one of the lobes being near Canada & Greenland remember before the beast in 2018 we had a similar setup with regards to that locale.

2018  12z gfs 

Here's why I was mentioning to keep a close eye on the severe cold pooling, 12z GEM watch the area I've highlighted 

Let's see how this run ends up though with this pattern that should be the general direction 

 

  

[BlueHedgehog074]

Just now, phil nw. said:

Yes see all that warm air advection heading north pumping up the High.

Sometimes the Azores high is the starter for a pattern change.1947 a good example.

Indeed Phil, and can help bust up the Vortex, particularly when you have 2 ridges of highly amplified High Pressure areas (2 wave pattern?) trying to slice the blue and purple monster up. A great thing to see. 

Is the case with the Azores High, it can act as both a friend and a foe for cold weather setups for the UK. Would probably say for the 12Z run, it’s been becoming kinda more of a friend, even if it was being a bit naughty nearer the start. In a way, the faster the Azores High is able to ridge North (trying to beat the Atlantic Lows from running over the top), the more likely and quicker the Jetstream out West diverts some of its Low Pressure to our South and strengthen any North-Western European troughing to our South or East. As longs I guess the pattern upstream behaves itself to make that happen. A more established European trough, providing it doesn’t set up too far West, then assisting in propping up Scandinavian/High Latitude blocking. From that (assuming the block was orientated favourably), a chilly visit from the cold and, at times, snowy choo choo from the East or North

[swfc]

Good evening 

I'd be very relaxed about the current output atm After yesterday's towel throwing its apparent that positioning of any areas of high pressure are going to fluctuate, "all speculative" atm. After a many a year 51 actually of watching and studying the nhp and synoptics the middle ground is generally a good place to aim. Remember the fluctuations are huge day to day unless you go 09/10.That said fi looks OK atm but give it 7-10 days

A

[Mike Poole]

2 minutes ago, January Snowstorm said:

I thought yesterday we were saying the parallel was the model to use as its the new one??

The one to use is the one that shows the highest likelihood of snow!

Seriously, I expect it is a quite modest upgrade so the two are as likely as each other given the massive uncertainty in the upcoming evolution.  

Meanwhile, most significant strat warming we’ve seen yet on the GFS T384:

[Frostbite80]

Starting to warm up above nicely

 

https://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=10&carte=1

 

 

 

 

[Cheshire Freeze]

Just now, Mike Poole said:

The one to use is the one that shows the highest likelihood of snow!

Seriously, I expect it is a quite modest upgrade so the two are as likely as each other given the massive uncertainty in the upcoming evolution.  

Meanwhile, most significant strat warming we’ve seen yet on the GFS T384:

Was just about to mention the warming.

Potentially on course for that late Dec SSW

[Kasim Awan]

4 minutes ago, DiagonalRedLine said:

Indeed Phil, and can help bust up the Vortex, particularly when you have 2 ridges of highly amplified High Pressure areas (2 wave pattern?) trying to slice the blue and purple monster up. A great thing to see. 

Is the case with the Azores High, it can act as both a friend and a foe for cold weather setups for the UK. Would probably say for the 12Z run, it’s been becoming kinda more of a friend, even if it was being a bit naughty nearer the start. In a way, the faster the Azores High is able to ridge North (trying to beat the Atlantic Lows from running over the top), the more likely and quicker the Jetstream out West diverts some of its Low Pressure to our South and strengthen any North-Western European troughing to our South or East. As longs I guess the pattern upstream behaves itself to make that happen. A more established European trough, providing it doesn’t set up too far West, then assisting in propping up Scandinavian/High Latitude blocking. From that (assuming the block was orientated favourably), a chilly visit from the cold and, at times, snowy choo choo from the East or North

Depends on the magnitude of the high, if it's strong enough it'll knock out any easterly bearing pressure gradient meaning the scandi high becomes synoptically irrelevant:

 

Edited November 21, 2022 by Kasim Awan

[Snowy L]

42 minutes ago, minus10 said:

Could be worse..

Very little low pressure to our South or Southeast though. Two things, nothing cold enough for snow, and unless something changes regarding the lack of low pressures the high eventually sinks. Oh and a third thing even if low pressure reinforcements do eventually go around the high and reach us from the East delivering the goods, a lot has to go right, or more accurately not go wrong, while waiting for that (e.g. no shortwaves messing things up)

 

Edited November 21, 2022 by Snowy L

[Methuselah]

2 minutes ago, swfc said:

Good evening 

I'd be very relaxed about the current output atm After yesterday's towel throwing its apparent that positioning of any areas of high pressure are going to fluctuate, "all speculative" atm. After a many a year 51 actually of watching and studying the nhp and synoptics the middle ground is generally a good place to aim. Remember the fluctuations are huge day to day unless you go 09/10.That said fi looks OK atm but give it 7-10 days

A

Indeed -- it's still only one run among many. But it's not alone in inching toward stonkery!

    

 

[tight isobar]

2 minutes ago, Kasim Awan said:

Depends on the magnitude of the high, if it's strong enough it'll knock out any easterly bearing pressure gradient meaning the scandi high becomes synoptically irrelevant:

 

Definitely.. However again the NE euro heights.. will be just an, aiding for waa “via circular momentum “- to rush through the Greenland/ Alaskan sector! .. And a possible carved - split PV. Pointless absolute looking for dripping @ minimal  overheads @ 850 ranges.. let alone probable surface plots!.. 1 things 4 sure the winter opening month... is looking great, if your of the cold persuasion..

[Kasim Awan]

2 minutes ago, tight isobar said:

Definitely.. However again the NE euro heights.. will be just an, aiding for waa “via circular momentum “- to rush through the Greenland/ Alaskan sector! .. And a possible carved - split PV. Pointless absolute looking for dripping @ minimal  overheads @ 850 ranges.. let alone probable surface plots!.. 1 things 4 sure the winter opening month... is looking great, if your of the cold persuasion..

Personally i dont see enough modelling of low pressure south of the uk to develop a "wintry" easterly - this component is a neccessity if the synoptic is too evolve from cold & frosty to cold & snowy. the positive tho is that the blocking looking to establish appears to have the potential to be expansive and potentially prolonged,  so at some point we run a possibility of dragging low heights under the block. 

[minus10]

12 minutes ago, Snowy L said:

Very little low pressure to our South or Southeast though. Two things, nothing cold enough for snow, and unless something changes regarding the lack of low pressures the high eventually sinks. Oh and a third thing even if low pressure reinforcements do eventually go around the high and reach us from the East delivering the goods, a lot has to go right, or more accurately not go wrong, while waiting for that (e.g. no shortwaves messing things up)

 

While i take your points its surely all about the trend...yes only one run and a thousand things could go wrong but...still nice to see hp in that position for a while though ...

[Maz]

3 minutes ago, Kasim Awan said:

Personally i dont see enough modelling of low pressure south of the uk to develop a "wintry" easterly - this component is a neccessity if the synoptic is too evolve from cold & frosty to cold & snowy. the positive tho is that the blocking looking to establish appears to have the potential to be expansive and potentially prolonged,  so at some point we run a possibility of dragging low heights under the block. 

Hi Kasim, I think WAA encouraging the high to retrogress to Greenland and open the door to a Northerly is a more likely and certainly safer route to wintery weather.  And more typical for December?

[bluearmy]

Extended ens geps and gefs are dropping euro heights and slp ……

geps is finished - gefs looks like it’s headed same way 

Edited November 21, 2022 by bluearmy

[minus10]

3 minutes ago, bluearmy said:

Extended ens geps and gefs are dropping euro heights and slp ……

Yes i would suggest for a z500 mean that is a pretty reasonable signal for raised heights to the north and lower heights to the south in the extended...