Model output discussion - proper cold spell inbound?

[chionomaniac]

I see the start of an Ω...........

[Mucka]

You have to laugh at that ECM run - it would be an awful, "winter is over" type run at the best of times but with a record breaking SSW event, well...

If we do get a good Atlantic ridge though the signal from there for a retrogressing high to set up is very strong

 

Fingers crossed we get it because a long cold spell is pretty much a lock in if we get through the first phase

 

[Kentish Snowman in Yorks]

1 minute ago, bluearmy said:

Looking at the eps clusters, there is a three way split at day 8 and the op could have easily picked the one which evolves like the gfs. I guess that means there is a 3/1 chance that ecm will come on board in he morning!

btw, the extended clusters are interesting if you like your troposphere running in reverse! 

It's actually only 2/1 if there is a three way split!  Not bad!

[Daniel*]

4 minutes ago, blizzard81 said:

The Control might be similar to the ecm though! I will be shocked if the gfs trumps ecm in this situation. 

The control is only out to T+6 and you’re already being a mystic meg? If you’ve been following the models religiously this winter you’d know ECM has not been great, none of models have.

[ICE COLD]

Some ice days if GFS 18z comes off ?

Edited February 10, 2018 by ICE COLD

[Daniel*]

I’d say GFS has been less emphatic this winter than ECM which should only mean it should be taken even more seriously GFS handled MJO better too! 

[ICE COLD]

7 minutes ago, blizzard81 said:

The Control might be similar to the ecm though! I will be shocked if the gfs trumps ecm in this situation. 

You were moaning that the ecm has been terrible this winter a few days ago ?

[WalsallWeather123]

GFS showing nonstop snow from 19-22 Feb across majority of country 

[Ice Day]

Another amazing run from the GFS and pleasing to see the inter-run consistency. This would feel bitter on the ground  

Edit, at 312, shall we have another Scandi High.....oh go on then!!!  There really could be something brewing here!

Edited February 10, 2018 by Ice Day

[Weathizard]

4 minutes ago, Daniel* said:

The control is only out to T+6 and you’re already being a mystic meg? If you’ve been following the models religiously this winter you’d know ECM has not been great, none of models have.

So what makes the GFS more likely to be right? Because it shows what we want?

 

Dismiss the ECM at your peril is all I will say, I hope the GFS is right but time and time again it's over progressive one way or another so I'm sceptical 

[Daniel*]

My only gripe with GFS is the uppers however that should be discussed much nearer to the time while not a mirror copy to GFS 12Z very good again GFS drum is beating loud. 

[Frosty.]

Last night's 18z was awful, tonight's is much more in sync with the background signals..hopefully the Ecm will be back on-board tomorrow!

[Daniel*]

2 minutes ago, Weathizard said:

So what makes the GFS more likely to be right? Because it shows what we want?

 

Dismiss the ECM at your peril is all I will say, I hope the GFS is right but time and time again it's over progressive one way or another so I'm sceptical 

Most likely it will be the middle ground and not GFS and ECM is right. The forecast I saw was thinking of easterly winds with blocking to NE, clearly the thoughts are with GFS for now. 

Edited February 10, 2018 by Daniel*

[Met4Cast]

ECM clusters aren't too bad - They show support for extensive Northern Blcoking but there is a cluster for a trough to our West, similar to the ECM op run

[Daniel*]

5 minutes ago, Weathizard said:

So what makes the GFS more likely to be right? Because it shows what we want?

 

Dismiss the ECM at your peril is all I will say, I hope the GFS is right but time and time again it's over progressive one way or another so I'm sceptical 

Yes too progressive in breaking down cold this is the contrary of its usual habits.  

We should always treat each run with scepticism but we all should know it’s in the spread of options and should not be disregarded.

Edited February 10, 2018 by Daniel*

[Daniel*]

Roughly a third from EC ensembles are going with GFS op you can’t say that’s insignificant. 

[ICE COLD]

3 minutes ago, Weathizard said:

So what makes the GFS more likely to be right? Because it shows what we want?

 

Dismiss the ECM at your peril is all I will say, I hope the GFS is right but time and time again it's over progressive one way or another so I'm sceptical 

Don't think anyone is dismissing the ecm op you would be silly to . But to be fair the ec hasn't covered it self in glory this winter . Few weeks back it was very progressive around 192 hrs and the other models wernt and it backed down it works both ways they all have there ups and downs ?. But the GFS is definitely gonna be right ?. (That's a joke ) no one knows ? 

[Catacol]

So - here we go. Vortex split, reversal to occur in the next 24-36 hours. Depth of reversal significant, length of reversal significant, vortex shard placement and progression a bit uncertain - but set to leave the UK in no man's land between the 2... surely providing a rich context to height rises to the north... maybe NE (my best guess) or maybe N to NW (as per some model runs recently..) Either way - height rises.

Still looking also for the storm track generally to drop south, though this has not been hugely noticeable in model runs in the last few days. Are the algorithms able to deal with a split vortex on top of an extended and deep reversal with a pacific context of high amplitude MJO and ongoing impact of east asian MT promoting the kind of poleward wave activity as posted so well recently by Masiello on twitter? And warming of the Canadian vortex shard on the horizon also? 

No. NWP will model all this far worse than usual. Wild swings will occur I think - with some awesome charts interspersed with downright ordinary looking ones. GFS just now churning out good ones - and this image here for medium term illustrates my thinking pretty well.

There have been some wise words in the last day or so, urging caution. They are right. Caution in weather forecasting is the name of the game - I suspect I have been guilty of being rather bullish in some recent posts. But at the same time - let's be clear. We havent seen a split and reversal like this in the modern record. Amy Butler has tweeted today that eddy heat flux has just broken the modern record and will be making a mess of vortex shape as I type. Sustained reversing strat winds for around 10 days are not something we have seen before - but are forecast. End result is that we have preconditions for something special.

To be honest - if we cant be excited now (coldie excitement that is) then frankly we never can be. 

[Daniel*]

The only thing I’m truly sceptical about is GFS making vortex rampant again near the end.

[Met4Cast]

Control is out to T150 and it's following the top, heights going North in the Atlantic, another stella incoming

[Bazray]

7 minutes ago, Catacol said:

So - here we go. Vortex split, reversal to occur in the next 24-36 hours. Depth of reversal significant, length of reversal significant, vortex shard placement and progression a bit uncertain - but set to leave the UK in no man's land between the 2... surely providing a rich context to height rises to the north... maybe NE (my best guess) or maybe N to NW (as per some model runs recently..) Either way - height rises.

Still looking also for the storm track generally to drop south, though this has not been hugely noticeable in model runs in the last few days. Are the algorithms able to deal with a split vortex on top of an extended and deep reversal with a pacific context of high amplitude MJO and ongoing impact of east asian MT promoting the kind of poleward wave activity as posted so well recently by Masiello on twitter? And warming of the Canadian vortex shard on the horizon also? 

No. NWP will model all this far worse than usual. Wild swings will occur I think - with some awesome charts interspersed with downright ordinary looking ones. GFS just now churning out good ones - and this image here for medium term illustrates my thinking pretty well.

There have been some wise words in the last day or so, urging caution. They are right. Caution in weather forecasting is the name of the game - I suspect I have been guilty of being rather bullish in some recent posts. But at the same time - let's be clear. We havent seen a split and reversal like this in the modern record. Amy Butler has tweeted today that eddy heat flux has just broken the modern record and will be making a mess of vortex shape as I type. Sustained reversing strat winds for around 10 days are not something we have seen before - but are forecast. End result is that we have preconditions for something special.

To be honest - if we cant be excited now (coldie excitement that is) then frankly we never can be. 

So have you stopped tapping your fingers now lol

 

[Ice Day]

4 minutes ago, Catacol said:

Amy Butler has tweeted today that eddy heat flux has just broken the modern record and will be making a mess of vortex shape as I type. Sustained reversing strat winds for around 10 days are not something we have seen before - but are forecast. End result is that we have preconditions for something special.

To be honest - if we cant be excited now (coldie excitement that is) then frankly we never can be. 

Edited to keep the quote short.

Brilliant post Catacol, the bit in bold is the key to what's unfolding in front of us.  We are, to some extent, in uncharted territory.  The models cannot be expected to handle this with any accuracy and I suspect by the end of next week we will be seeing major changes within 96 hours.  Days 7-28  could produce some incredible weather and definitely some amazing model output. 

Just please enjoy it folks, spring isn't far away when we'll all drift away to normal life for another 8 months.

[Snowjokes92]

6 minutes ago, Daniel* said:

The only thing I’m truly sceptical about is GFS making vortex rampant again near the end.

I dont know why when the models are all over the place for the coming week, nevermind a 384 chart. Also to add to that, the models will make wild swings like the 18z at the end anyway. Especially when the models are struggling to pin point where the northern blocking will take hold this week. The 18z also gets in another scandi high at the end but starts to collapse. Again the models are still struggling with heights building in the shorter term, never mind towards end of the month

Edited February 10, 2018 by Snowjokes92

[Mucka]

On 06/02/2018 at 06:41, Mucka said:

It's a long way out and not much to go on but something like this could be very snowy (or wet)

Anyway continues the theme of better dig SE and lowering of heights into central Europe.

 

 

I have been talking up a possible snow event next week since last Tuesday, still looks as plausible, if as marginal, now as then so can't claim credit for that yet.

But it is interesting to see how the models performed since I made that observation.

Below is the output I highlighted back then with today's for the same period - you would have to say that is pretty damn good job by ECM, especially as it was around 9 days out the time of posting. 

 

Below is what GFS was showing, so ECM had a much better handle on how the PV would behave - quite accurate in fact

Edited February 10, 2018 by Mucka

[Catacol]

5 minutes ago, Bazray said:

So have you stopped tapping your fingers now lol

 

Nope - not quite. We have to get through this first

followed by a bit of this (though uppers will be good for high ground snow)

before suddenly at the weekend we get the anticipated, and very sudden, trop response to the split and warming

- so my fingers have a fair bit of drumming to do yet. I wonder if there is a chance this weekend starting "gun" may be brought forward? No prediction there - just musing. It is possible.

Edited February 10, 2018 by Catacol