Model output discussion - 7th January onwards

[Weathizard]

Decent agreement low a bit deeper on the GFS, there has been a trend to make it less of a clean ridge to our west with more energy spilling over, might still be alright though.

[frosty ground]

By day 5 the Two area of heights still haven't linked up. (not that it will make a major difference.) 

[Deep Snow please]

7 minutes ago, Rocheydub said:

Seriously? On every run pre 96 you comment upgrade/downgrade all the time. Will you let it run it’s course until at least 120? The early nuances rarely have big impacts on the overall picture.

 

sorry if this sounds cranky, I’m tired and emotional!

Not even midday, country going to the dogs etc.  

 

Anyway, back to the charts.Thinks looking okay at T96, a bit too mild personally but in the right direction.

 

[kold weather]

The other thing to note is the cold NNW flow before the easterly has strengthened a little on the recent runs as the LP moves to our east instead, so we end up on the arctic side quicker (though it does reduce snow risk). -6C widespread by 120hrs so cold coming in now within reliable timeframe, regardless of easterly down the line.

[shaky]

Very good 06z so far!!

[Met4Cast]

Any further corrections East and the pattern collapses, GFS 6z is about the Eastern limit you'd want and the overall pattern remains relatively safe

Suspect they'll be many ENS members further West and some further East which collapse the pattern. Not a terrible start to the mornings runs, view the GFS Det as part of the ensembles and you should get a clearer picture when they roll out. Fairly good consistency.

[Weathizard]

Good consistency, GFS much better now, ECM better heights to our north. Swings and roundabouts

Edited January 18, 2019 by Weathizard

[IDO]

1 minute ago, shaky said:

Very good 06z so far!!

Yes kinks more prevalent in the flow so much better for snow chances.

Usual caveats.

[Johnp]

The over analysis in here is incredible!

Variations on a theme people, and that theme is cold.

As for Snow, that always crops up at short notice, plenty of surprises to come!

[weathertoski]

2 hours ago, nick sussex said:

An over riding sense of relief this morning !

The UKMO is an improvement even though it takes some shortwave energy east not as much as last night.

You’d still want more margin of error though . 

Overall the models that weren’t interested are now moving in the right direction .

The ECM and GFS are variations on the same theme from last night . In terms of snow off any easterly to be honest it’s pointless worrying about convective potential at this stage . Two reasons models are hopeless at picking that up in the longer range and we don’t know the exact strength of the flow and other factors this far out .

I still think we need one more full set of runs just to be sure and hopefully we can have no more dramas!

 

Perfect charts for big snowfalls next week on the north side of the Pyrenees Nick! If you are still in that neck of the woods?

[kold weather]

Just now, Daniel Smith said:

Any further corrections East and the pattern collapses, GFS 6z is about the Eastern limit you'd want and the overall pattern remains relatively safe

Suspect they'll be many ENS members further West and some further East which collapse the pattern. Not a terrible start to the mornings runs, view the GFS Det as part of the ensembles and you should get a clearer picture when they roll out. Fairly good consistency.

Its close, that's been a trend on most morning runs is to make it much tighter and it was why I was quite worried this morning, I've seen such spells come unstuck through just such situations with little shortwaves running along the frontal boundary too many times.

In this case, we do have the Arctic high to help so it still looks pretty good out there.

06z GFS should be ok and whilst it may not be as god as some runs, its going to be good enough I'm fairly confident.

[shaky]

scrap that this is an amazing run so far!!!strong north east winds and also we must not forget the northwester before hand could give a good covering of snow further north and west!

[kold weather]

2 minutes ago, Johnp said:

The over analysis in here is incredible!

Variations on a theme people, and that theme is cold.

As for Snow, that always crops up at short notice, plenty of surprises to come!

Definitely going cold now, the main question though is whether we just go cold, or whether or not we can go into the next league and go for one of those legendary long cold spells. Its on the table for sure...I think people know that and so want it to really come off.

[Rocheydub]

Just now, shaky said:

scrap that this is an amazing run so far!!!strong north east winds and also we must not forget the northwester before hand could give a good covering of snow further north and west!

Case in point. The will it/won’t it up to T120 is meaningless. Let it run through!!!

 

Night shifts have been tough. Apologies!!!

[frosty ground]

The Atlantic will break under the block on this run which is good news as the block will be positioned further north.

[Scandinavian High.]

All still fine every model run will be different but on the same page colder weather on the way even colder later next week ..

[Singularity]

 

Currently we're not seeing the scenario of interference from the Atlantic D5-D6 because the upper ridge is already too far advanced northward to allow it. Comparing 06z with 00z reveals barely any change there. As long as (usual caveats here!) the upper ridge continues to build at this pace, the surface ridge should be able to join forces with the one from the Arctic.

[kold weather]

As BA would like to say, this 06z GFS is a variation of the same theme, in this case at least to start looks the wind flow is more of a true NE direction rather than ENE/E like some of the previous runs, mainly due to the fact its all setting up that bit further NE than previous runs, but its still very cold, probably very snowy for east coast and Kent in particular.

[IDO]

The slower process this run means that the colder air keeps feeding the Euro trough:

The first is the 0z. Slows the warming out and holds it further north. That means when the easterly comes the colder uppers will be further north, 

[Frosty.]

Isn't it wonderful to look at the models and not see anything mild?...all I'm seeing is varying degrees of cold with potential for very cold / severe cold!..good times indeed..long may it continue!

[kold weather]

4 minutes ago, Singularity said:

 

Currently we're not seeing the scenario of interference from the Atlantic D5-D6 because the upper ridge is already too far advanced northward to allow it. Comparing 06z with 00z reveals barely any change there. As long as (usual caveats here!) the upper ridge continues to build at this pace, the surface ridge should be able to join forces with the one from the Arctic.

Agreed, the only risk we would have is if the surface high sets up too far SE due to any shortwave cutting across. its still going to be cold but that would make a world of difference to our snow prospects in the medium term at least for obvious reasons.

Flow is suggestive of less showery activity inland on this run, coastal areas would still do well...but probably doesn't make a huge deal at this stage.

ps, I like the way the set-up is looking downstream at 168hrs though!

Edited January 18, 2019 by kold weather

[Methuselah]

1 minute ago, kold weather said:

As BA would like to say, this 06z GFS is a variation of the same theme, in this case at least to start looks the wind flow is more of a true NE direction rather than ENE/E like some of the previous runs, mainly due to the fact its all setting up that bit further NE than previous runs, but its still very cold, probably very snowy for east coast and Kent in particular.

Was about to say the very same thing, kold...With plenty opportunity for precipitation, given the scope for some kinky isobars:

[JoeShmoe]

1 minute ago, Singularity said:

 

Currently we're not seeing the scenario of interference from the Atlantic D5-D6 because the upper ridge is already too far advanced northward to allow it. Comparing 06z with 00z reveals barely any change there. As long as (usual caveats here!) the upper ridge continues to build at this pace, the surface ridge should be able to join forces with the one from the Arctic.

Yes, although how many times have we seen energy / shortwaves pop up at T+96 and less in the GIN corridor in these setups. Lets hope that doesnt happen but cold is so fragile to get in the UK it only takes small mesoscale events to ruin potentially great setups .. 

[kold weather]

Wonderful downstream pattern at 168hrs, negative tilted upper trough is going to promote the LP to dive SE and try to undercut the Scandi block. Providing no drama happens, this could help to support the pattern quite deep into FI. 

[IDO]

As per recent output, the Atlantic moving in around D8, undercut: