Model Output Discussion - the cold has arrived

[Tim Bland]

Much better 06z for end of next week. Cleaner separation with a stronger ridge causing lows to slide south east.  00z Vs 06z below 

[Snowmadsam]

Morning morning morning!

Just now, frosty ground said:

Speaking of delays, after getting the mild blip down to 36 hours it’s looking more like 72 hours now, the cold return a has been delayed but it’s still being touted 

tbh, that’s a more preferred timeline, not from a meteorological view but from a human point of view. People are struggling at the moment.

it’s better to give a little respite before anything else. At this moment a seasonal Christmas (chilly temperature wise) would do me personally.

the 6z’s do paint a nice potential picture for the future, well based on what I’ve seen rolling out at the moment (gfs op only)

[Battleground Snow]

Nice little wedge, is it enough to slide that low for us?

[nick sussex]

Essentially here the longer the delay in phasing the better prospects for colder weather because the early phasing is a symptom of a less favourable block set up allied with a more deeper football shaped low over the UK .

You have lots of competing interests here .

Block saying I want to force the pattern se , the low saying hang on I like it further ne .

The phasing saying to the low do you want a helping hand ne .

[Snowmadsam]

sliding more than people slide into my insta dms, opens the Northerly door. 
 

Greenland high tries to push East, Azores high  retrogressing West…

[Lukesluckybunch]

Lovely at 192..similar to ECM

[goosey007]

Knife edge stuff with the phasing.........but back  to were were with GFS 

[Hotspur62]

2 minutes ago, Battleground Snow said:

Nice little wedge, is it enough to slide that low for us?

Agree,could really do with centre of low over shetlands just being 50-100 miles further east and keep it just a bit further from low in mid Atlantic.Gives us a bigger wedge and angle of slider will be better.This is going down to the wire.Nothing is ever straight forward in getting cold for the U.K. but if this does happen it could really have implications down the line but I am getting way ahead of myself there.

[nick sussex]

I really wouldn’t worry too much about post day 7 because as the pattern is very fluid and small changes earlier will domino into wildly different outcomes later .

 

[goosey007]

Chalk a cheese 0z and 6z

[ITSY]

2 minutes ago, Snowmadsam said:

sliding more than people slide into my insta dms, opens the Northerly door. 
 

Greenland high tries to push East, Azores high  retrogressing West…

Just for the imaginative people among you lot, we're awfully close to a full on snowstorm for the South on this chart. Probably one of those high-risk/high-reward scenarios but it's not without support. Good that the 06 GFS has followed the 00Z ECM. As we *slide* closer to the 144-168 timeframe things will start to firm up in the next few days so the trend is our friend...

[Snowmadsam]

Just now, ITSY said:

Just for the imaginative people among you lot, we're awfully close to a full on snowstorm for the South on this chart. Probably one of those high-risk/high-reward scenarios but it's not without support. Good that the 06 GFS has followed the 00Z ECM. As we *slide* closer to the 144-168 timeframe things will start to firm up in the next few days so the trend is our friend...

100% agreed. Also, with that airmass, don’t rule out surprises down the coast lines. It is a Polar Low after all. Seas are still warmer than usual….

 

but yes, high risk high reward. it is only one run. 

[Derecho]

Held off from commenting on that GFS 00z and thought it may be too progressive, especially with the improved EC.

Hopefully people can see what I mean about getting in that cold earlier, less moderation of that arctic airmass to our west and less chance of phasing with any lows further west.

Fingers crossed we can continue with those eastwards corrections.

[ITSY]

You'd take that on Xmas eve - dry or not, it would be the most festive in many a year! 

[kold weather]

This December really is interesting, you can tell when your going to have a cold month usually because the models will keep being forced top push back the milder stuff and any milder breakdowns downgrade as you get closer.

'Kinda the reverse to what we get most winters.

Anyways given we had siuch an explosive blast of HLB last week ,it comes as little surprise that the models are starting to really trend towards another weaker HP over the Greenland area. Beyond that I'd guess the whole lot will get shifted SE and perhapsm a HP block starts to develop nearby to the UK, possibly just E/ESE of the UK. Thats a decent holding position, especially in an arctic setting prone to shifting strongly -ve AO as it keeps the colder European air coming in keeping a lid on things, but also primes for any attempt stronger HLB to get going again.

[Cambrian]

More thaw than Thor by 108h on the 6z GFS op.

    

But remember when a fierce battle ensued between the Asgardians and the Frost Giants, although Thor enjoyed the battle, easily defeating his foes, his allies were soon overrun by hordes of Frost Giants.

192h

    

That’s the truth, that is - and there was nothing thaw…er, I mean, Thor…could do about it. Big wuss. 

[goosey007]

Christmas day ice bowl anyone......BANK

[IDO]

This slack westerly flow with troughs and cold ridges/highs much better than the usual zonal winters we get. The highs are mid-lat so even when pressure rises we keep the cold right out to D10+, apart from the brief respite from the SW'ly from the weekend. So at D11 a cold UK high:

[booferking]

Better trend this morning for sure North-westerly turning northerly on the run up to Christmas snow showers packed in and small troughs with more persistent snow bands then i can see the polar high joining forces with the emerging Siberian/Russian high along with the Atlantic high creating a monster block with winds turning Easterly.

[Battleground Snow]

Decent improvement on the mean too, on to the 12zs we go

[Johnp]

If offered, I’d take this now for Xmas. Nice and festive but no travel disruption.  Then hope the high migrates favourably in the days after to give us a beasterly…

 

[Mark wheeler]

24 minutes ago, goosey007 said:

Chalk a cheese 0z and 6z

Cheese please  

[IDO]

The slack flow means the trough takes days to clear, feeding the cold into the basin, and also means when the high moves in, that takes days to progress allowing it to bell fingers of heights into higher latitude, as per the 06z:

Obviously, still post-D7 subject to changes due to micro features impacting, but I feel something like this flow is now where we are heading.

[frosty ground]

4 minutes ago, IDO said:

The slack flow means the trough takes days to clear, feeding the cold into the basin, and also means when the high moves in, that takes days to progress allowing it to bell fingers of heights into higher latitude, as per the 06z:

Obviously, still post-D7 subject to changes due to micro features impacting, but I feel something like this flow is now where we are heading.

Still cold at the surface under that high 

[nick sussex]

The GFS control is interesting in that the cold air hangs on in the far north and Scotland .

A few other ensembles do similar .

Its hard to see a huge change to save others snow given the timeframes . It would need a miraculous change .

But again its a good bellwether going forward as the less advance the mild mush makes the likely better blocking set up and shallower low .