Model output discussion - Closing in on Christmas

[frosty ground]

As telegraphed by the Jet profile the Ridge is toppling but what chance of a second bite of the cherry? 

[Allseasons-Si]

That Scuasian block is more prevalent on this run and disrupts that Scandi trough hmmmm!,what would come out of this? 

[That ECM]

1 minute ago, Daniel said:

It's gonna topple to much energy coming out of the states. Yet anouther run which is different to its previous. 

Yep, there is heights trying to squeeze up between the two lows but a bit pointless looking into much detail as this yet another different outcome gfs has decided to churn out.

[Matt H]

Looks like we might have another shot at t216, but with another significant divergence from its previous output it’s hard to take it seriously.

[Vikos]

Compairing 12z today to 12z from yesterday and 00z yesterday

 

Yet again, GFS is rather useless after 192h

[Daniel]

I hope no one from Ireland is in here unsettled Christmas if the gfs was right. Thankfully its just the gfs for now

[Howie]

Hoping the UKMO is correct with less energy coming from Canada 

[frosty ground]

5 minutes ago, Allseasons-si said:

That Scuasian block is more prevalent on this run and disrupts that Scandi trough hmmmm!,what would come out of this? 

[Thunder and Lightning]

Just now, Daniel said:

I hope no one from Ireland is in here unsettled Christmas if the gfs was right. Thankfully its just the gfs for now

Hopefully none of the models join this trend

Low pressure really breaks into the UK this run. At least the flow on this is still NW not SW 

[weirpig]

Much better gem 12z

[nick sussex]

Oh dear !

The GFS upto its old tricks .  Now it wants to drop the low se and go onto the next mystery tour with a tease from the ne .

The good thing is that even with it relieving its youth at Woodstock and dropping loads of acid it still is struggling to find a mild solution ! 

Edited December 16, 2020 by nick sussex

[Allseasons-Si]

1 minute ago, nick sussex said:

Oh dear !

The GFS upto it’s old tricks .  Now it wants to drop the low se and go onto the next mystery tour with a tease from the ne .

The good thing is that even with it relieving its youth at Woodstock and dropping loads of acid it still is struggling to find a mild solution ! 

All roads lead to cold Rome Nick

[Zak M]

GEM 00z vs 12z

   

Much better run this. There's not much ridging from the continent on the 12z, which helped inject the colder air. The -6c isother gets into southern England as well.

Edited December 16, 2020 by Zak M

[frosty ground]

Its an impressive chart it really does look like all routes lead to cold,

 

[That ECM]

Coldies in Algeria and Tunisia are watching this run and shouting Boom Baby

[Duane S.]

Personally I think that trough droping SE through Boxing day  is a very likely outcome. Short term pain for long term gain.

I would 100% bank it.

[feb1991blizzard]

Still on for my 20th-30th jan SSW prediction.

@s4lancia  I would bank it because of the huge PV split!

 

Edited December 16, 2020 by feb1991blizzard

[That ECM]

7 minutes ago, s4lancia said:

Personally I think that trough droping SE through Boxing day  is a very likely outcome. Short term pain for long term gain.

I would 100% bank it.

I would also but you really think gfs has this about right?  

Edited December 16, 2020 by That ECM

[Matt H]

I take back what I said about the GFS, it’s a brilliant model.

[Howie]

You know what, I'll take what the GFS is showing

[Ice Day]

I mean, what the heck!!!!  How on earth will the PV get its act back together after this ?

Clearly, the pattern is nowhere near nailed, even out to 144.  But I do love that these mad FI synoptics keeping getting churned out.  This FI run is up there with last nights pub run shenanigans!

[Zak M]

12z GFS has a small low @324 travelling southwards that would produce snow on its NW flank

   

[nick sussex]

The expected pattern in the USA for mid next week is an amplified troughing set up into the Rockies in response to the amplified ne Pacific ridge.

The downstream correlation to that is an amplified ridge in eastern Canada and amplified mid Atlantic troughing .

The GFS tries to get there but its  bias blows up that low to the nw . You would expect that to be less deep and sharper with more trough disruption.

With that in mind the low dropping down in that fashion would more likely slide se as a weaker feature and not phase with the low over Denmark .

The evolution from there would then be different but still cold .

Positively even with a series of misfortunes the GFS attempt at Christmas Grinch fails.

In the UK you tend to have an all or nothing scenario with cold so if one evolution fails you’ll left with zip .

So it’s encouraging that several evolutions are shown with still a cold end point .

[Anthony Burden]

GFS 12z very intriguing high pressure lasting for 1 day that being Christmas Day after that low 

pressure continues all be it colder than at present.The most notable to me being that North Russian 

1065mb high pressure.

[Trom]

1 hour ago, Mike Poole said:

I think there are 3 reasons for this.  First, the evidence, from the verification stats the GFS is not as good a model as ECM:

At day 5 it is behind the ECM, UKMO and just behind the GEM (CMC on chart).

Secondly, it runs 4 times a day so gets more airtime.  Thirdly, all its output is freely available, whereas only limited output is available free from some of the other models.  So you see more output from GFS on here for those reasons.  

 

Presumably these are verification stats for the entire northern hemisphere.  I always assume (possibly incorrectly) that they would be much lower for the UK in isolation, given we are sat at the edge of an ocean with a continent to the east.