The hunt for cold - Model discussion (late November)

[feb1991blizzard]

Not bad at all.

Compared to the 0z.

Edited November 30, 2018 by feb1991blizzard

[tight isobar]

12 minutes ago, johnholmes said:

Hi, I simply posted what was the basic standard when I was forecasting, perhaps things have changed in the 20 or so years since I hung up my forecast hat.

Tbh honest john..your a fantastic man of overall..-meteo,knowledge-.

However.. a lot is now swayed on human input (imo)..

Which is increadable 'given' the advances in scope/computer accom.

But as we gain in tech...we also do in the way of thought/decipher 2 compete with the tech-analysis!!..

And 4 that im sure..more precise forecasts will be both..challenging..and to the marker!!..

If we take LRF-MODS-throughout a 12 month equation/analysis...

And breakdown verbal input/output via person interp....

The man chatting...is likely 'closer the mark'.

...lol...but not 4getting..computer in-out is/was in-design by .....man himself!!!

I have different devation/interps/outs..

And i won't change that 4 any1!!!..

So- nor should yourself!!!..

Full respect for persons like yourself...whom minamal-or major..have got meteor/atmos-science...2 where we are now!!!..

Edited November 30, 2018 by tight isobar

[ICE COLD]

1 hour ago, feb1991blizzard said:

I would be 1000ft up if i had'nt had to move here in a rush (this is the lowest point in the whole parish), the problem here is people keep going up and down the main road and putting salt down so it needs a continual pasting to keep them in bed and maintain a decent snow cover.

Ha ha ha feb . You remind me of myself . Love it when we get a nice deep layer of snow and then my neighbor starts clearing the paths , ruining all my nice snow . It’s so annoying. 

[The Northern Ramper]

5 minutes ago, feb1991blizzard said:

Places only 1 and a half miles away got 5 foot drifts last winter.

There was chains of people passing supplies to the m62 a minute from my house and my road (an A road) was closed.

[bluearmy]

The eps control is a colder versions of the gfsp 

@feb1991blizzard - does the presence of the mean ridge on ecm T240 mean anything yet ???

despite the obvious swing seen today, I’m still 50/50 .........let’s see what happens as higher res picks up the difficult bits re phasing to our west and more amplification over n America slowing down the systems to allow the ridges to manifest themselves 

 

[northwestsnow]

3 minutes ago, bluearmy said:

The eps control is a colder versions of the gfsp 

@feb1991blizzard - does the presence of the mean ridge on ecm T240 mean anything yet ???

despite the obvious swing seen today, I’m still 50/50 .........let’s see what happens as higher res picks up the difficult bits re phasing to our west and more amplification over n America slowing down the systems to allow the ridges to manifest themselves 

 

Agreed.

A swing away from a rampant +NAO today

..

[Stuie]

Really liking the trend of the JS via the FV3, dives way south into week 2. This whole week 2 scenario is really shaping up but I cannot contradict myself in saying there is faith in this.

There is a trend though.

 

[feb1991blizzard]

2 minutes ago, bluearmy said:

The eps control is a colder versions of the gfsp 

@feb1991blizzard - does the presence of the mean ridge on ecm T240 mean anything yet ???

despite the obvious swing seen today, I’m still 50/50 .........let’s see what happens as higher res picks up the difficult bits re phasing to our west and more amplification over n America slowing down the systems to allow the ridges to manifest themselves 

 

Yes, i do believe that the general pattern with another round of scandi heights that GP and others have touted a) will materialise and b) needs to materialise for our sake further into January, however, it will in my opinion with a strong Northern arm, remain too far to the East for any deep cold to be advected our way this month, we might get close towards the end of December. even the teleconnections guru's have remarked that the atmosphere is behaving like a super nino - when have we ever had a proper block set up in December with such a pattern?

[Mike Poole]

My take on the 12s as a whole, from an uncertainty point of view, given the timescales we're talking about, day 8 to 10 being the period of interest.  

My first thought on seeing the 12z op suite compared to the 0z and yesterday's 12z, in the context of the model output over a slightly longer timescale (few days) was 'regression to the mean' - in a system with high uncertainty, the idea that if you get 6 reds in a row on roulette, you might expect at some unspecified time in the future to also get 6 blacks i.e things average out in the end. So if the previous runs were biased to pessimistic given the level of uncertainty, we might expect a good set of runs anyway.  

What moves me away from this, towards an actual signal for an amplified solution in the vicinity of the UK at the day 10 timescale, is the ECM mean and spread.  This looks more signal than noise, and if it is firmed up on the 0z then I think we have a new route to cold being firmed up.  I'm holding fire from ramping it for another 12 hours.

Edited November 30, 2018 by Mike Poole

[Tim Bland]

Ensembles are still a bit disappointing. Not many runs getting below the magic -5c 

Edited November 30, 2018 by Tim Bland

[Mike Poole]

CFS watch, as it's 30 Nov, last chance to view what CFS is showing on average for December, here's the latest surface pressure anomaly for the NH - last 8 runs:

AA

All look very negative AO - it's a start, but correlation of -AO to -NAO is only about 0.7 I believe, so yes good signals, but still some uncertainty of course, let's watch how all this pans out....

Edited November 30, 2018 by Mike Poole

[Summer Sun]

GFS continuing to go with a north/south split next week as it has done for quite a few runs now

[Mike Poole]

ICON even showing the increasing amplification at T120 on the 18z, T126 on the 12z for comparison:

 

[Ice Day]

It's been a funny few days on here with emotions seemingly running high in some quarters, which seems a bit strange since winter only starts tomorrow (well, in about 2 hours time actually!).  Having spent far too many hours studying winter models and learning from those far more learned than me on here, it's clear that trying to predict anything more than 7 days into the future is a fool's errand. 

As today's models have shown, pattern changes can crop up at very short notice.  Not saying 'snowmaggedon' is on the cards for 10 days time, but small changes at day 3 mean big changes at day 6 and so on.  Let's hope the momentum towards cold is continued over the days ahead, and if not, it's only the weather after all.  

Let's have a pub run special to kick-start the weekend.

[SMU]

Just @ JFK - 

Seen the Debilt T2Ms- biggest signal yet for cold...

[ICE COLD]

4 minutes ago, Steve Murr said:

Just @ JFK - 

Seen the Debilt T2Ms- biggest signal yet for cold...

Wow they have taken a dive . Compared to the last few days that is a very good graph . Funny how it all changes so quickly. 

[Snowman.]

GFS has merged the eastern seaboard low. Will be interesting to see how what happens later on down the run.

[Paul]

Since there's a glimmer of cold being talked about right now, maybe it's a good moment to let you know the Xmas theme is available now

 

 

[northwestsnow]

Are we going to get some energy into the southern arm on this run so as to pump up the azores high?

[SMU]

The 18z GFS looking identical to the 12z FV3 at 192 - so expecting a decent amount of amplification similar to the ECM EPS...

Edited November 30, 2018 by Steve Murr

[bluearmy]

Clusters - only 12% go with the control .....there are still five in the extended so  the message remains ‘wait and see’. The pattern in the 9/10 day period is amplified but the three clusters pre day 10 then look very unconvincing post day 10. 

[ICE COLD]

8 minutes ago, Steve Murr said:

The 18z GFS looking identical to the 12z FV3 at 192 - so expexting a decent amount of amplification similar to the ECM EPS...

And we end up like this at day 10 . 

[ICE COLD]

This is at T300 and it looks good but the pv over Greenland is a pain in the ar*e

Edited November 30, 2018 by ICE COLD

[Mike Poole]

GFS 18z is following every other model, the blocked outcome is coming, GFS at T216:

Edited November 30, 2018 by Mike Poole

[ICE COLD]

The trend is definitely are friend today .