Model Output Discussion - the cold has arrived

[MJB]

Not a great morning eh? 

Unless some of the white stuff falls , it will be a disappointment .......................for many I guess , and the spell will get a low rating 

[Snowyowl9]

Days and nights will be getting colder and colder..

Then we have this icy cold easterly..

Plenty of freezing fog and a few ice days to come..

Now if we re looking at other options here are a couple later to keep the cold going at least..

 

[mhielte]

4 minutes ago, MJB said:

Not a great morning eh? 

Unless some of the white stuff falls , it will be a disappointment .......................for many I guess , and the spell will get a low rating 

A lot of assumption there in one post. Let's not get hasty and instead evaluate after the event, rather than before. After all, we're talking science here and rarely do you evaluate your results before the experiment even takes place! 

[andy989]

More snow last night and I’ve been told it’s snowing down in Caernarfon at sea level. 

Patience folks, we are only 2 days into the cold spell. With regards to “breakdown”, models always show breakdowns, ALWAYS. Every cold spell I remember it’s longevity was never known before hand, breakdowns were being shown but always out in FI and pushed back. Don’t worry until those “breakdowns” gather support and tick down from day 10 

[zubzero]

36 minutes ago, Eagle Eye said:

Yes, I got that 46 number a couple times but I don't know how because others are saying 7KM, what I don't understand is how there isn't a definitive source somewhere on the Internet, surely someone has done that. I mean, even the sites that are supposed to be government ran talking about the models are out of date, there's not much I could find for every model away from the years 2012 and 2016 for whatever reason.

It tells you on meteoceil at the bottem of each model ARPEGE is 10km resolution for Europe and 0.5 for the world. 

GEM is 15km for the World. Ect

 

[jules216]

Sorry mods. No model related, ať my area where I lived 6 years there was Snow last night 5cm and temperatures tumbled to -9 this morning. As my first hobby is "Frost Hunter" and I ve been searching for cold spots in Slovakia fór 3 years now installing dataloggers,stations to Frost hollows I believe west Wicklow would have broken All tíme records in 2010. But no one measures there,no station in wunderground database etc. And I believe if I was a Frost Hunter back in 2010 I would have found and measured -20°C without a shadow of doubt.

[bluearmy]

5 minutes ago, zubzero said:

It tells you on meteoceil at the bottem of each model ARPEGE is 10km resolution for Europe and 0.5 for the world. 

GEM is 15km for the World. Ect

 

That could be resolution of the charts being produced rather than the resolution of the actual model run. 

Edited December 9, 2022 by bluearmy

[ANYWEATHER]

1 hour ago, Snowmut said:

 Well sadly less than a week to go on this chart its looking like we'll  still be dreaming of a white Xmas for another year! Unless your a hobnail goat on a mountain somewhere!

 

So you believe every day runs...? For a start ,last week's Iberian low was set to spoil the Wintry weather, then there was another spoiler for early next week. When we have cold in place it's hard for models to simulate a non default pattern which we have now, and is certainly locked in ,I think for the rest of this month and beyond. If anything it's going to get colder as we move into next week....

[bluearmy]

Look out for an eastern USA  trough which drives a downstream mid Atlantic ridge in the 9/12 day period. 
 

[northwestsnow]

Excellent runs this morning..

At least another week of locked in cold..

In a warming world on the edge of an ocean ...

 

[iowpompeylee]

Looks to be plenty of activity down around the south coast as highlighted on the MO fax chart tomorrow into Sunday. If I’m reading it right

[TSNWK]

3 minutes ago, ANYWEATHER said:

So you believe every day runs...? For a start ,last week's Iberian low was set to spoil the Wintry weather, then there was another spoiler for early next week. When we have cold in place it's hard for models to simulate a non default pattern which we have now, and is certainly locked in ,I think for the rest of this month and beyond. If anything it's going to get colder as we move into next week....

Disagree.  The previous attempts to breakdown were micro scale in the scheme of things with lows attempting to break down the macro pattern of vortex over Asia and Greenland heights. What is different for the breakdown now being modelled day 7 and beyond is the macro pattern shifting to enable it..  vortex relocation over the artic and losing Greenland heights.

[Met4Cast]

29 minutes ago, MJB said:

Not a great morning eh? 

Unless some of the white stuff falls , it will be a disappointment .......................for many I guess , and the spell will get a low rating 

Will it?

Snow or no snow, by the end we would have seen 3 weeks of below average temperatures, by UK standards that's pretty damn good. 

It does seem that support is growing for the cold spell to end around the 18th/19th December but until that gets to within 5-7 days it can't be fully discounted that the cold will hang on for longer, indeed quite a few EPS members continue the cold on past this date. The previous cold spell ending was the 14th, so it has already been pushed back by 4/5 days. 

FWIW MOGREPS + UKMO keep us locked into cold, that combined with a cluster of colder EPS members.. any breakdown remains far from certain.

Edited December 9, 2022 by Met4Cast

[ANYWEATHER]

9 minutes ago, TSNWK said:

Disagree.  The previous attempts to breakdown were micro scale in the scheme of things with lows attempting to break down the macro pattern of vortex over Asia and Greenland heights. What is different for the breakdown now being modelled day 7 and beyond is the macro pattern shifting to enable it..  vortex relocation over the artic and losing Greenland heights.

Yes day 7 and beyond .....

[keithlucky]

Merry Xmas all , With iceland turning very cold this for 23rd December.

[zubzero]

12 minutes ago, bluearmy said:

That could be resolution of the charts being produced rather than the resolution of the actual model run. 

Maybe it says the UKMO run is 10km and that's what it is so I assumed it was right. 

[jmp223]

Couldn't agree with a couple of posters above, so many people (myself) included were convinced that the Iberian low would scupper our chances of cold uppers.  The models are only as good as the assumptions they are based on, and constantly being tweaked. While indeed generally accurate, our foremost meteorologists are far, far away from understanding all the drivers behind the function of the tropospheres, never mind its interaction with the strat., solar cycles etc.  And especially where there is cold encroaching on our small island, the margins are so, so fine it's is exceptionally difficult to predict the intricacies of it and where and when and if it will snow.

I'm keeping faith on this event delivering snow, always believed in the adage get the cold locked in and wait and see what comes next.

Edited December 9, 2022 by jmp223

[BlueHedgehog074]

Have noticed the ECMWF, and particularly the UKMO, exhibit a wave feature across South-Eastern parts of the UK Wednesday next week:

00Z UKMO

 

00Z ECMWF

 

Precipitation associated with it is more widespread on the UKMO (probably due to the stronger and more bendier flow), albeit mostly affecting Eastern/South-Eastern parts. Might be something worth monitoring over future runs and see if other models start picking out something like this. Because even if the Azores/Atlantic Low not do much, it’s one way wintry events can come about through things like that. 

Do personally feel, having a wavy disturbance like that get to 00 hours, especially if it was like how the UKMO show it, the wintry precipitation would probably be a bit more expansive. Particularly with it coming off a mild/warm North-Sea. Just seems under-estimated on the above models. 

[TSNWK]

1 minute ago, ANYWEATHER said:

Yes day 7 and beyond .....

true.. but I think wiith Macro changes there is a little more confidence as like a large oil tanker (Next weeks macro change being modelled ) that once the course is set it takes more effort to change, unlike a small speed boat (the lows attempt to breakdown) which  can zip around more.

[That ECM]

8 minutes ago, iowpompeylee said:

Looks to be plenty of activity down around the south coast as highlighted on the MO fax chart tomorrow into Sunday. If I’m reading it right

I agree, looking at various suggested radar for the near term and over the weekend I think some will be pleasantly surprised. I’m not talking loads but seeing something falling is a possibility. 

[Mike Poole]

ECM ensembles T168 (or some of them anyway!):

And here’s the way out!  As @bluearmy rather cryptically noted above, there’s a sizeable number of these that put up a ridge in front of the low that would otherwise bring the downfall of the UK cold spell were it to cross the Atlantic and impinge on the UK bringing air from the south.

Here’s perturbation 12 to illustrate what I mean:

It will be really interesting to see if this option gathers traction - it would gain traction if the models are currently underplaying the potential to maintain or re-build heights in the Greenland area, and it is entirely plausible that they may be.  One to watch.  

Edited December 9, 2022 by Mike Poole

[MJB]

30 minutes ago, mhielte said:

A lot of assumption there in one post. Let's not get hasty and instead evaluate after the event, rather than before. After all, we're talking science here and rarely do you evaluate your results before the experiment even takes place! 

My evaluation of any cold spell will be if I get snow total IMBYism I'm afraid - and I have to say this experiment has failed many many times lol

[That ECM]

2 minutes ago, That ECM said:

I agree, looking at various suggested radar for the near term and over the weekend I think some will be pleasantly surprised. I’m not talking loads but seeing something falling is a possibility. 

 

[iowpompeylee]

1 minute ago, That ECM said:

I agree, looking at various suggested radar for the near term and over the weekend I think some will be pleasantly surprised. I’m not talking loads but seeing something falling is a possibility. 

I’m trying to nail down other models views on Saturday into Sunday as we may see a covering during the weekend. The little disturbance Sunday isn’t going away by the looks of it. The south east could see some  snow as highlighted earlier in the thread! 

[TSNWK]

Just now, That ECM said:

 

looks decent - are there the uppers / DP / Surface temps to support snowfall though?