Model Output Discussion - moving into Winter

[Bats32]

1 minute ago, Cold Winter Night said:

EC 240h.

No cold available, they said.

It should be hung in the Louvre!

[blizzard81]

1 minute ago, Allseasons-si said:

Re-load at day ten,..."FANTASTICO"

Is that high over in the Pacific trying to come over and shake hands with the Greenie high?

[Allseasons-Si]

The ECM and jma at day ten

[I remember Atlantic 252]

5 minutes ago, Ice Day said:

A very good run, but I am slightly surprised that the uppers are as high as they are between 168 and 216

  

Just small areas of -8 with the majority of the country in the -5/6 range.  Given the source of the air mass, I would have thought they'd be 3 or 4 degrees colder.  Perhaps the warmer than usual North Sea is moderating them higher?  Absolutely not a moan, just an observation.  We are certainly in an extremely good place given that tomorrow is the first day of winter proper!

 

Noticed that, probably due to front moving down from the north

[nick sussex]

I’m happy . This set up drives some warm air into Cyprus where I’m visiting family and at the same time brings in a northerly flow into the UK so coldies get  some snow .

Looks like the ECM made the right call and the GFS did its normal messing about .

Not sure what will happen with the upgrade ! 

Edited November 30, 2022 by nick sussex

[sheikhy]

Looks like gfs was an outlier as early day 4 or 5 with the handling of the iberian trough!

[Allseasons-Si]

That would be cold enough...

[Alexis]

8 minutes ago, Ice Day said:

A very good run, but I am slightly surprised that the uppers are as high as they are between 168 and 216

  

Just small areas of -8 with the majority of the country in the -5/6 range.  Given the source of the air mass, I would have thought they'd be 3 or 4 degrees colder.  Perhaps the warmer than usual North Sea is moderating them higher?  Absolutely not a moan, just an observation.  We are certainly in an extremely good place given that tomorrow is the first day of winter proper!

 

Probably warm sectors behind fronts. If you want precipitation you're not going to avoid them - hopefully "warm" will still be cold enough in such a setup.

[Vikos]

13 minutes ago, Allseasons-si said:

The ECM and jma at day ten

Looks like a uterus ready to give  birth to  

Edited November 30, 2022 by Vikos
Bad English 😂

[Dancerwithwings]

Wow… I’m lost for words as I don’t think I’ve ever come across anomalies * yes  two Heights like that on show in this chart * not sure who’s higher them or me

[Mark Smithy]

Wow

[Frosty.]

My cup runneth over this evening! ..here’s the GEM 12z! ️…coldies deserve this!..the huge amount of mild dross we have to endure, hopefully consigned to the wheelie bin for a good while!!!  

Edited November 30, 2022 by Frosty.

[carinthian]

11 hours ago, carinthian said:

Morning all. I have a bit of an update this morning from the team. At 192t their charts still show a NE ly flow across much of the British Isles. As shown on ECM a bit of a battle scenario likely to develop across Southern Britain by this time next week. Their own outputs would indicate any precipitation within this boundary to be corrected further south nearer the event with a strong view that denser colder air advecting south will win out this time. GFS recent outputs seem to be arrowing away from its mean as it continues to come to terms with developing scenarios  to the SW. Overall, looks like a promisingly good start for the winter season in your latitudes, less so over here !. Should get the first results later today from the snow modeling  and will report back of any interest to you guys.

C

One of the interesting variations in the outer parameter results this evening from the snow model does show some snow being registered on highground on Sunday ( approximately North of the Humber Flue) Snow level 400m falling to 250m at times. This would indicate some form of convective activity coming off the North Sea. Distance and time affect reliability in the predictions in the fine mesh model used over here so percentage success rate always a bit on the low side. But its there . Back in the Eastern Alps , not much snow is currently predicted for the next 7 days. Although we have a general cover that will allow the new ski-ing season to start this weekend, fohn conditions are expected over here on Sunday. I will get back tomorrow morning with an update from the team regarding Blighty  up coming cold spell.

C 

[Jason M]

3 minutes ago, I remember Atlantic 252 said:

Noticed that, probably due to front moving down from the north

The problem with northerlies these days is often twofold. First problem is the source is not as cold as it used to be (that will be true here) and secondly northerlies in recent years have been fleeting. The first point about source matters a fair bit less where the airflow stays in place for longer (which looks likely here). A third point which actually helps us is that we are rapidly approaching the shortest day so solar input will be low. So, whilst -5/-6 uppers are a little bit meh for a maritime airflow, we will probably be okay for snow. Are we looking at subzero days and deep snow? Doesn't look like that to me. Decent winter cold spell looks increasingly likely but nothing severe (at least at the moment ).

If we do manage to get a covering of snow on the ground over the next few weeks that will really impact daytime highs. 

[geordiekev]

Beast from the North East?

[AFCBSNOW]

42 minutes ago, Polaris said:

Hope so mate. Just feeling a little underwhelmed- whilst the NHF is eye watering, none of the major models bring 850s for snow away from mountains in the reliable. Just hoping it’s a slow burner. 

If you underwhelmed by this, then its the wrong hobby for you my friend.  Its simply stunning for this time of year.

[Cambrian]

12z ECM at day 10 - can’t see what all the fuss is about to be honest. 

T850s only 7 or 8 degrees below normal for mid-December, maxima struggling to get to 2 degrees for the vast majority and low pressure features readily developing in an unstable northerly airflow.

   

Hardly any potential for anything out of the ordinary there 

[ANYWEATHER]

11 minutes ago, Jason M said:

The problem with northerlies these days is often twofold. First problem is the source is not as cold as it used to be (that will be true here) and secondly northerlies in recent years have been fleeting. The first point about source matters a fair bit less where the airflow stays in place for longer (which looks likely here). A third point which actually helps us is that we are rapidly approaching the shortest day so solar input will be low. So, whilst -5/-6 uppers are a little bit meh for a maritime airflow, we will probably be okay for snow. Are we looking at subzero days and deep snow? Doesn't look like that to me. Decent winter cold spell looks increasingly likely but nothing severe (at least at the moment ).

If we do manage to get a covering of snow on the ground over the next few weeks that will really impact daytime highs. 

I think you will find that that the cold north wind is just as cold as times gone by, just look at those Artic temperatures,  and so early in the season it's simply fridgid

[geordiekev]

I know we're a few days out to pin down flow direction, moisture etc but I recall recently a similar set up and the lake effect from Skagerrak straight was immense and walloped the East Coast. The kind of activity snow charts don't factor in

[January Snowstorm]

It will be interesting to see how the very warm sea temps modify the flow. You would imagine the warm seas and cold temps will only enhance the shower activity. To get this type of weather so early in the season really is special, perhaps some younger folk don't realise the extremity of what could develop!

[mushymanrob]

19 minutes ago, Mark Smithy said:

Wow

Excuse me, are you the same Mark Smithy who insists you cant take any notice of charts past T168, yet here you are posting a favoured chart at T240?

[phil nw.]

27 minutes ago, Allseasons-si said:

The ECM and jma at day ten

What a run from both models si but tbh no less than the Ecm suites have pointed too for a few runs now.

A great angle of attack from the dropping Scandinavian trough.

If we get to this point Arctic air over a warm sea should induce disturbances in the flow giving areas of snow heading south west into the UK.

The first half of December promising to be increasingly exciting for cold lovers I think.

[Frosty.]

There’s plenty to like about the GEM   12z mean / perturbations..here’s a small sample!… there is an incredible feel good factor about this forum..hope it continues!  

 

[johncam]

6 minutes ago, ANYWEATHER said:

I think you will find that that the cold north wind is just as cold as times gone by, just look at those Artic temperatures,  and so early in the season it's simply fridgid

Not completely true as I have already said very little sea ice in Barents and Svalbard regions compared to days gone by ,also seas warmer than normal so temps will be warmer than we could expect 

[Snowmadsam]

5 minutes ago, January Snowstorm said:

It will be interesting to see how the very warm sea temps modify the flow. You would imagine the warm seas and cold temps will only enhance the shower activity. To get this type of weather so early in the season really is special, perhaps some younger folk don't realise the extremity of what could develop!

agreed, could easily see very shallow areas of low pressure develop in such a flow, plenty of convergence lines too. Good luck to forecasters doing FAX charts with these synoptics.