Model output discussion - the beast arrives

[Stuie]

8 minutes ago, bluearmy said:

 

Thanks very much (thumbs up smiley)

[Purga]

9 minutes ago, bluearmy said:

 

Thanks for that Nick - reminds me of the state of my guts just before checking the latest model runs!

[pages]

18z Icon has both high further east and lower further marginally south at t-48 trend continues...

18z-

 

[Stuie]

Ok, are we saying 8 members place the LP to the South of Ireland/ SW England?

[Man With Beard]

38 minutes ago, bluearmy said:

Eps have a spread which more reflects the icon days 6/7. 

Wonder if it will show as a discreet cluster later on ? 

Gone through most of the ensembles, by Monday morning it's about 45% with a pattern likely to sustain cold (low to SE or E) and 55% unlikely to sustain the cold (low just to W, SW or on top of us).

The UK is the dividing line!!

[ANYWEATHER]

Evening ,those on here pointing to an unprecedented  ,historic ,intense cold spell and liking this to the likes of 1947 and 1963 and the likes is very misleading.  First of all the so called pipe freezing weather won't happen !  Central Europe back in 47 and 63 was frozen solid couuppled  with deep bitter cold from the East Britain caught the cold from the continent. This time round central Europe until recently has been snow and ice free, It's a shame that some posters on here have hyped this cold spell along with the media out of proportion,  Central Britain could well do well for snow forget Blizzards for the south....

[Mike Poole]

The ICON confirms its move to a reassertion of the block in recent runs, particularly evident in the ECM mean earlier.  I expect future runs to follow this, meaning extending the cold spell, possibly weakening Friday's event for some.  Here at T108

[Tim Bland]

ICON is awesome with10-20cm over most parts of England and Wales by Sat with cold air still in place. Also the prospect of  another snow event later in the weekend / early next week! Fingers crossed for the ECM to be on the same page tomorrow!

 

 

[Man With Beard]

Desperate times call for desperate model hunting! The ICON-EU has just updated, 10-20cm of snow widely across the south, Midlands and Wales on Friday, 30-50cm for hills in the west, and up to 70cm in East Ireland!

@ANYWEATHER - but some of these historic charts + build up are very similar to what's coming end of this week. Like the Met Office say "small chance" of "severe" disruption but they haven't put Thursday/Friday's event in the highest potential impact category for nothing!!

[pages]

2 minutes ago, Mike Poole said:

The ICON confirms its move to a reassertion of the block in recent runs, particularly evident in the ECM mean earlier.  I expect future runs to follow this, meaning extending the cold spell, possibly weakening Friday's event for some.  Here at T108

Yep if Icon is trending nicely in the t-0 - t-48 range upgrades to cold spell to come I reckon the lower may go further south and we get reload from north east with snow showers personally I would rather somewhere gets a blizzard and hope its my area as never really had a proper blizzard in my life time.

[Zakos]

11 minutes ago, Mike Poole said:

The ICON confirms its move to a reassertion of the block in recent runs, particularly evident in the ECM mean earlier.  I expect future runs to follow this, meaning extending the cold spell, possibly weakening Friday's event for some.  Here at T108

I agree, such deep cold air is unlikely to displaced this quickly imo    thats an incredibly hasty warm up from the gfs for western Europe in just over 48 hours... I dont buy it...

Edited February 26, 2018 by Zak94

[bluearmy]

20 minutes ago, Stuie W said:

Ok, are we saying 8 members place the LP to the South of Ireland/ SW England?

It says that there is an area sw of Ireland where there is a cluster up to 5/6 dam away from the mean which is 520. (Probably lower).  This is a spread on heights. I guess this cluster holds the cold pool a little further back than the mean (and op) which have it further sw.

[johnwirral]

Why are the big 3 models expected to follow the ICON when they have been correcting north consistently?

[chionomaniac]

9 minutes ago, ANYWEATHER said:

Evening ,those on here pointing to an unprecedented  ,historic ,intense cold spell and liking this to the likes of 1947 and 1963 and the likes is very misleading.  First of all the so called pipe freezing weather won't happen !  Central Europe back in 47 and 63 was frozen solid couuppled  with deep bitter cold from the East Britain caught the cold from the continent. This time round central Europe until recently has been snow and ice free, It's a shame that some posters on here have hyped this cold spell along with the media out of proportion,  Central Britain could well do well for snow forget Blizzards for the south....

No one is/was calling a 63 47 type spell. And with heavy snow falling outside with no marginality I think that this severe cold spell is notable. It seems that you have been trying to knock it for the last few weeks. Well it is here, we have deep cold and it is delivering. You must be living in a different planet because there is a risk of a severe blizzard for later this week - the only thing not known at the moment is how marginal it will be in the far south.

[bluearmy]

Just now, johnwirral said:

Why are the big 3 models expected to follow the ICON when they have been correcting north consistently?

Would be a surprise tbh but it’s still on the table 

[Don]

Just now, johnwirral said:

Why are the big 3 models expected to follow the ICON when they have been correcting north consistently?

It's called hoping!! 

[Philbill]

8 minutes ago, Zak94 said:

I agree, such deep cold air is unlikely to displaced this quickly imo                                                 thats an incredibly hasty warm up from the gfs for western Europe in just over 48 hours... I dont buy it...

It does make me wonder at times how well the density of colder air is factored into model algorithms

Edited February 26, 2018 by Philbill

[Eastnorthwest]

Evening each and the snow has arrived today here with at least 2 more almost sub zero days to come with snow for most then the usual atempt of a push from the south of a low to create a battle ground setup giving heavy snow for inland areas and middle blighty and maybe nearer the coast as well depending on uppers ,but compared to 3 days ago the severe cold that was shown by most models seems to have all but deminished to the northern half of the UK by Friday

Haven  said that it's still the best setup we have seen for 5 years and one which could produce a re serge of favourable colder setups in the coming couple of weeks,let's hope so

[Stuie]

3 minutes ago, bluearmy said:

It says that there is an area sw of Ireland where there is a cluster up to 5/6 dam away from the mean which is 520. (Probably lower).  This is a spread on heights. I guess this cluster holds the cold pool a little further back than the mean (and op) which have it further sw.

Cheers BA, once I get my head around this, interesting tool.

[Catacol]

21 minutes ago, ANYWEATHER said:

Evening ,those on here pointing to an unprecedented  ,historic ,intense cold spell and liking this to the likes of 1947 and 1963 and the likes is very misleading.  First of all the so called pipe freezing weather won't happen !  Central Europe back in 47 and 63 was frozen solid couuppled  with deep bitter cold from the East Britain caught the cold from the continent. This time round central Europe until recently has been snow and ice free, It's a shame that some posters on here have hyped this cold spell along with the media out of proportion,  Central Britain could well do well for snow forget Blizzards for the south....

You are guilty here of using hindsight. The modelling has taken a turn because the easterly has been so damned good that it has overshot the landing zone thanks to super fast block retrogression. There were whispers of western -NAO risk, but at the time of such claims the modelling was suggesting just such a historic spell. As it is there is a chance for sustained cold and snow, but when the scandy block disappears so quickly to Canada the chances of it being historic will fade.

It's ironic really. We wait years for a pattern that can be exceptional and get all the building blocks in place, and then the reversed pattern just hits so hard that it overcooks the conditions we need. I suspect a number of us are eyeing up the reload potential as we head further into March, but agree that the season is now so late that marginal conditions for snow are likely to be the best we get until Spring. Meanwhile the current week is the most interesting in a long time and maybe we can get some minor height rises to the north to preserve the general easterly flow in the longer term.

Everything is very easy with hindsight. 

Edited February 26, 2018 by Catacol

[Derecho]

May amount to nothing but the low on this GFS looks a fair bit deeper but also further south...

ICON is still good, lets hope for some improvements for down here after the underwhelming 12z output for the weekend. The ensembles at least suggested it's still in the balance. I really don't want cold rain lol

Edited February 26, 2018 by Quicksilver1989

[Zakos]

1 minute ago, Philbill said:

It does make me wonder at time how the density of colder air is factored into model algorithms

Me too. I'm not clued up on the science behind it, but I have heard that this is the case before on this forum. I believe the density of this brutally cold air should make it harder to shift. I believe "thickness"  charts indicate air density

Even without a block holding cold air in situ, logically it should be more difficult to shift than a less cold air mass. 2 days for a large swath of Europe seems awfully quick. The GFS has already backed down from its rapid breakdown, and it appears the 18z may be following the same trend...

[Duane S.]

18z not quite ready to throw in the towel...

 

[Djdazzle]

GFS 18z seems further south and east with the low.

[pages]

11 minutes ago, johnwirral said:

Why are the big 3 models expected to follow the ICON when they have been correcting north consistently?

Because the ICON has been performing well lately; it what the 1st model to spot the initial Easterly, and while the othesr flipped around with wild swings of our far north/south easterly setup it pretty much showed it where is currently is today a week ago. It seems at least at match for the big 3 during this reversal of strat winds don't know why. Once we are back to normal type patterns I expect the others will outperform it again.