Model output discussion - proper cold spell inbound?

[Kentish Snowman in Yorks]

2 minutes ago, nick sussex said:

Just to explain what I mean by energy separation in case people are thinking whats going on!

These are the ECM day 7 and 8 charts.

So in the first one you have the UK low and you can see low heights connect this with the upstream trough, if you don't get that separation the ECM would drag the upstream trough further east so think of it as a car towing another along.

ECM day 7:

Now as you can see in the day 8 chart you've cleared that attachment from the UK so the upstream trough cant get that tow over the UK, the ridge gets ahead of it.

As an amplifying   shortwave runs east across Canada on day 9 it then attaches to the PV lobe which has a pivot action again pulling the PV back and allowing the ridge to get pushed ne ahead of it.

So we want the tow rope to snap?!  

The ECM does look much more promising going forwards from a cold perspective than the GFS run I will admit.

[Matthew.]

12 minutes ago, Radiating Dendrite said:

All the blocky GFS runs have been in lala land though. It throws out these scenarios daily, people are just jumping on these because of the SSW event. 

As has been said, SSW is not the golden ticket to cold. It just offers help but no guarantee, similar to many other teleconnections.

SSW are about as close to a golden ticket as your going get though for certainty of a proper cold spells though. Ones chasing cold and more importantly snow in the last 3rd of Feb have the most reason to do so. ECM later on looks interesting to say the least.

[MR EXTREMES]

1 hour ago, chionomaniac said:

I think that we can now say that the ECM is starting to reel in. Let's hope that trend continues.

Indeed starting to show the Atlantic blocking and the drop of lower pressure to our south.

If we can get the Atlantic blocked into the 144 time frame then I strongly believe the ECM will remain the king of the models.

The jma yesterday also showed a very similar evolution.

The gem this morning is all over the place GFS is also a bit messy.

Ukmo 144 looks interesting lots going on from the Mets model.

But all the time I see charts from the ECM showing changes to blocking I have no concerns.

[nick sussex]

Just now, Kentish Snowman said:

So we want the tow rope to snap?!  

The ECM does look much more promising going forwards from a cold perspective than the GFS run I will admit.

Exactly yes. The GFS has no separation and you can see how that sunk without trace!

[Jonathan Rhodri Roberts]

GEM looks really good for the start of half term as next weekend it brings us high pressure, light winds and 11C could this last throughout the school holidays up to the 25th who knows but we would be off to a very springlike start 

Edited February 9, 2018 by Jonathan Rhodri Roberts

[Froze were the Days]

ECM has struck me as being late for picking up the cold snaps this winter and by and large has followed in GFS footsteps only for GFS to go on another less cold tangent...will we see some plum ECM runs over the next day?...probably so but may be only to drop them or 'water' them down closer to the event. That seems to be the trend in my eyes this winter watching the models...

Edited February 9, 2018 by Froze were the Days

[nick sussex]

3 minutes ago, Jonathan Rhodri Roberts said:

GEM looks good for the start of half term as next weekend it brings us high pressure, light winds and 11C could this last throughout the school holidays up to the 25th who knows but we would be off to a very springlike start 

Your post was about as welcome in here as a bikini salesman in down town Jeddah! 

We only wheel out the GEM in here if it shows a cold solution otherwise it’s a cannon fodder model! 

[bluearmy]

Judging by the ec46 and the latest eps I suspect the Exeter outlooks may well firm up a little further on a cold to very cold outlook

the eps seem to have grasped the expected evolution - blocked to our north in general and jet deflected south. 

 

[Froze were the Days]

CFS monthly runs not exactly picking up a cold/very cold signal either, March/April 2013 it was consistent with it's runs showing blocked conditions.

[Frosty.]

6 minutes ago, nick sussex said:

Your post was about as welcome in here as a bikini salesman in down town Jeddah! 

We only wheel out the GEM in here if it shows a cold solution otherwise it’s a cannon fodder model! 

This Gem 00z really isn't in the script is it nick!!..sending an urgent sos to Steve murr!

[Severe Siberian icy blast]

10 minutes ago, bluearmy said:

Judging by the ec46 and the latest eps I suspect the Exeter outlooks may well firm up a little further on a cold to very cold outlook

the eps seem to have grasped the expected evolution - blocked to our north in general and jet deflected south. 

 

Good news however, I still think we all need to hold fire, the warming hasn't happened yet and the models and ourselves are trying to second guess where the blocking sets up, we need clear operation of the 2 vortex globes with no residual parts left in order to get blocking at true high latitudes, 

I think once the warming has happened the models will begin to firm up on where exactly the blocking occurs

Edited February 9, 2018 by Severe Siberian icy blast

[Daniel*]

23 minutes ago, Jonathan Rhodri Roberts said:

GEM looks really good for the start of half term as next weekend it brings us high pressure, light winds and 11C could this last throughout the school holidays up to the 25th who knows but we would be off to a very springlike start 

Just so you know high pressure doesn’t necessarily mean there’s no chill. Everything is currently hinting away from that fantasy of yours. We are struggling with forecasting next week let alone the 25th!   

Certainly a delayed spring is looking very likely I regret to inform - actually no I don’t. 

T240 GEM is chilly in SE slack continental flow less so for the NW subject to SW’ly but this looks fleeting this chart definitely arouses curiosity..

[Decemberof2010]

Have the wheels fallen off already??? I always get that feeling when the GEM is posted. Not a great start to the day I must say. If we can't get cold and snow from this SSW, then I'm completely changing hobbies and I will start collecting stamps 

[bluearmy]

6 minutes ago, Daniel* said:

 

Certainly a delayed spring is looking very likely I regret to inform - actually no I don’t. 

Does anyone want a delayed spring for chilly nothingness ?? M

doubt it

busy three days upcoming on here 

 

 

Edited February 9, 2018 by bluearmy

[jethro]

I'm 100% convinced that the SSW is going to turn this country into wintery nirvana shortly. Do I suddenly have an insight into model reading? Kinda......Google has turned snowy this morning, clearest signal yet that winter is far from over ;-)

[Daniel*]

Just now, Decemberof2010 said:

Have the wheels fallen off already??? I always get that feeling when the GEM is posted. Not a great start to the day I must say. If we can't get cold and snow from this SSW, then I'm completely changing hobbies and I will start collecting stamps 

*self inflicted bangs head violently against a wall* How so? GEM only come up into discussion as it brings up ‘springlike’ for a time apparently & day 10 is intriguing for cold persuasion. Given everything it’s the sort of range we’re looking at. ECM continues in a similar vein very good with UKMO it doesn’t go our far enough yet to have a true sense of what’s in the air following SSW. GFS 00z not good but 06z will be probable be better. I see nothing has changed. 

[Nick F]

43 minutes ago, bluearmy said:

Judging by the ec46 and the latest eps I suspect the Exeter outlooks may well firm up a little further on a cold to very cold outlook

the eps seem to have grasped the expected evolution - blocked to our north in general and jet deflected south. 

 

Yes, the extended 00z EPS shows -ve H500 anomalies  developing over Azores and toward NW Africa and +ve heights in the GIN corridor which suggests quite a few members pulling the jet on a southerly track under a block to our north, been quite rare this -NAO signature, the NAO hasn’t been -ve since late November, so always a little sceptical of it verifying, but with a SSW likely impacting the trop quickly, a -NAO east based more likely than it has been all winter of actually verifying.

Given the ECM is recognised as having better modelling of the upper atmosphere and thus strat-trop interactions, you’d side with this model over GFS once them SSW is inevitable. My only criticism of the 00z EC op, and don’t get me wrong, it’s miles better at day 10 than GFS, is that the low that breaks away east from the retreating PV to our NW does so on quite a northerly track and so waters down the cold air to our E and NE ahead of it before the low heading east hits the block over west Russia, sinks and pulls in an Ely or NEly flow. So this wouldn’t mean a quick plunge into deep cold.

But Low tracks and orientation of ridges unlikely to verify that far off, so as long as the upper patterns in the broad scale evolve in a similar fashion over subsequent runs, with Atlantic ridge building NE, then perhaps not worrying too much about depth of cold for now.

on a final note, GEFS AO and NAO still tanking

Edited February 9, 2018 by Nick F

[Daniel*]

10 minutes ago, bluearmy said:

Does anyone want a delayed spring for chilly nothingness ?? M

doubt it

busy three days upcoming on here 

 

 

March can be a wintry month even in the south if things align favourably to get some deep cold in. In the far north it very much is a winter month and should be treated as such. As some have said timewise potentially we are ahead of 2013 by several weeks and that month featured ice days in second half of the month. I don’t think it’s unreasonable to think an unusually cold March may be on the way even when coldest March since 1962? Was five years ago. Weather doesn’t go by this one in 50 year malarkey it does what it wants at any time potentially the potential is there but also very much so for this month.

Edited February 9, 2018 by Daniel*

[That ECM]

Can some post the ukmo t168? I'm out and haven't got the link. It will have in view an area of interest and would be interesting to see. TIA

[ICE COLD]

11 minutes ago, bluearmy said:

Does anyone want a delayed spring for chilly nothingness ?? M

doubt it

busy three days upcoming on here 

 

 

I do if it brings scenes like this ?

[Summer Sun]

3 minutes ago, That ECM said:

Can some post the ukmo t168? I'm out and haven't got the link. It will have in view an area of interest and would be interesting to see. TIA

Sure

[bluearmy]

11 minutes ago, Daniel* said:

March can be a wintry month even in the south if things align favourably to get some deep cold in. In the far north it very much is a winter month and should be treated as such. As some have said timewise potentially we are ahead of 2013 by several weeks and that month featured ice days in second half of the month. I don’t think it’s unreasonable to think an unusually cold March may be on the way even when coldest March since 1962? Was five years ago. Weather doesn’t go by this one in 50 year malarkey it does what it wants at any time potentially the potential is there but also very much so for this month.

You missunderstand me Daniel - I was merely saying that a delayed spring is only worth it if we see proper wintry conditions at the surface. If we end up between the real cold and the less cold then on reflection, it won’t have been worth it. 

We have no idea what will transpire ...

[BLAST FROM THE PAST]

What we have here and what we need to hold on with is that each model could be right.

The deep LP coming in midmonth is agreed on an initial low track with plenty of cold air in the mix.  But what happens after that.  

We could have a massive block to E NE only for orientation wrong and block too far east so we have S or even SW flow.  Or it could fall right and ECM outcome happens.  Uncertainty is there, I for one am a tad concerned....

Normally I’m bullish for cold...but the rhythm of the winter has not been conducive to it thus far and the models even with some consistency with nirvana then change and back off, water down and reach middle-ish ground.

 

BFTP

Edited February 9, 2018 by BLAST FROM THE PAST

[Daniel*]

2 minutes ago, bluearmy said:

You missunderstand me Daniel - I was merely saying that a delayed spring is only worth it if we see proper wintry conditions at the surface. If we end up between the real cold and the less cold then on reflection, it won’t have been worth it. 

We have no idea what will transpire ...

I understood that. I would say however things are looking reasonable at this embryonic stage. I’m certainly no fan of a real delayed spring but it’s got to the extent, I’ll take what I’ll get when it comes. Snow shield five years and strong. A pretty punishing hobby to have sometimes, but we do get breaks every once in a while..

[ACCOUNT DELETED]

50 minutes ago, Jonathan Rhodri Roberts said:

GEM looks really good for the start of half term as next weekend it brings us high pressure, light winds and 11C could this last throughout the school holidays up to the 25th who knows but we would be off to a very springlike start 

No it doesn't, for any "springlike" feel at this time of year you need sunshine & very light winds. This happened last week when despite it being 6C on the thermometer it felt very mild, that GEM run would bring a lot of cloud and therefore would feel quite chilly. 

I get that not everyone likes snow and of course with half term being just a week away many people will be hoping to get out and about and go on short breaks with their kids. Don't forget easterly winds can often bring drier air especially here in the west with cold but sunny days if the Atlantic fronts are kept away they're often the main ones to watch as they can bring persistent, heavy snow especially as sea temperatures are around their seasonal lowest.