Model output discussion - Winter has arrived

[northwestsnow]

Gawd I hope GFS is right...

Super 18z ....

[northwestsnow]

So much better then EC ...

[Catacol]

57 minutes ago, Downburst said:

Couldn’t agree more. We have negative angular momentum for most of the rest of the month (and only starting), a very classical La Nina pattern indeed, specifically a high pressure anomaly northern Russia into Scandinavia. It’s primed to produce the goods at anytime over the next couple of months

Hmmm - not really. Angular momentum remains above 0 and we are in a more Nino GWO orbit than Nina. This is exactly why we are seeing an unexpectedly amplified pattern and convection forcing from the equatorial pacific is bigger than the standard RMM pots are letting on. Long may it last because it gives us half a chance of northern blocking later in the month as a sustained feature, and a greater chance of wave flux penetrating the vortex.

Edited December 4, 2020 by Catacol

[damianslaw]

On 03/12/2020 at 20:47, Mucka said:

 

Last night and today proof once again if needed you don't need very cold uppers to produce snow, indeed most of our snow comes in very marginal situations, fine margins. 

[Tim Bland]

I must be the grinch today because I got cold rain but...this looks worse than the 12z to me

Edited December 4, 2020 by Tim Bland

[northwestsnow]

In fairness the difference between 12z and 18z at day 10 are so vastly different it suggests GFS literally hasn't got a scooby doo...

Edited December 4, 2020 by northwestsnow

[bluearmy]

3 minutes ago, northwestsnow said:

In fairness the difference between 12z and 18z at day 10 are so vastly different it suggests GFS literally hasn't got a scooby doo...

Continuity is an issue with the Russian block causing problems ..... the lack of an organised tpv remains in coldies favour .....

[Snowman.]

5 minutes ago, Tim Bland said:

I must be the grinch today because I got cold rain but...this looks worse than the 12z to me

Lacks the necessary amplification later on to make it worth it. Still plenty of time with many of the models offering different options so its nothing to worry about.

[Allseasons-Si]

2 minutes ago, northwestsnow said:

In fairness the difference between 12z and 18z at day 10 are so vastly different it suggests GFS literally hasn't got a scooby doo...

Yes a mere observation for the newbies,this not aimed at you @Tim Bland,ten days is a long way out in model terms and never come to fruition

stick to the reliable 5-6 days as it's so much better on the ticker

there is still lots to be resolved with the undercutting scenarios if it even happens,this is the crucial timeframe.

[SMU]

The keytime 138 control + ENS heading in the right direction - Low in neg tilted on 18z Mean

[Allseasons-Si]

8 minutes ago, Steve Murr said:

The keytime 138 control + ENS heading in the right direction - Low in neg tilted on 18z Mean

Isn't that the 12z/18z mean in comparison?

control at 138...

looks better all the same.

 

Edited December 4, 2020 by Allseasons-si

[Mike Poole]

Yes similar to the ECM mean, the 18z GEFS shows the Atlantic running up against the block not pushing through, here T 174:

The lows are inclined to slide, but it is easier to see what is going on from a NH perspective: 

 

[Anthony Burden]

For sure charts are finding it very hard to get any consistency past  144 hrs except for 

one RUSSIAN HIGH maybe the key to every door for cold lovers.

[BLAST FROM THE PAST]

GFS heading for record cold miss/ HP plunge by t384?

 

 

BFTP?

Edited December 4, 2020 by BLAST FROM THE PAST

[northwestsnow]

18z shifts the PV North of Scandy at the end and its a very cold run in the main.

Everyone is entitled to their opinion  I prefer GFS to be right over UKMO and EC..

Its a long shot..

Edited December 4, 2020 by northwestsnow

[bluearmy]

Just now, northwestsnow said:

18z shifts the PV North of Scandy at the end and its a very cold run in the main.

Everyone is entitled to their opinion  on prefer HFS to be right over UKMO and EC..

Its a long shot..

I think they’re all throwing stuff against the wall at the moment NWS .... we don’t know what’s likely to stick though ! 

[Allseasons-Si]

The control looks good at 192 but again...someone stole the cold uppers

all speculative this far out in terms of uppers.

 

[Jason M]

10 minutes ago, bluearmy said:

I think they’re all throwing stuff against the wall at the moment NWS .... we don’t know what’s likely to stick though ! 

The one thing we know isn't going to stick is any snow. Lots of good looking synoptics but nothing particularly cold.

[Catacol]

Vortex stress building.

[Allseasons-Si]

Now,where have i seen that chart before?

[damianslaw]

23 minutes ago, Jason M said:

The one thing we know isn't going to stick is any snow. Lots of good looking synoptics but nothing particularly cold.

Uppers equal if not better than today in synoptics shown and there was snow. As I said do not need very cold uppers for snow. Indeed the synoptics shown if anything increase likelihood if snow as there would be more moisture and hence heavier precipitation and hence greater evaporative cooling.

I don't normally comment on GFS 18z 384 hr output but once again GFS toying with Greenland high, over 1070 mg. Interesting to see how an eventual Atlantic assault aids this, allows an amplified azores high to ridge and build north and hold, but with the PV away from Greenland it sends the Atlantic trough to Scandi, end up with ridge heading north and eventual retrogression, scandi slicer. Incoming freezing cold.. 

Edited December 4, 2020 by damianslaw

[Daniel*]

Trust UKMO to dangle a big carrot.

[northwestsnow]

My first reaction to UKMO is positive ....

Looks very complex but hoping we see a Scandy High as 00z UKMO depicts...

[northwestsnow]

GEM day 10..

[northwestsnow]

For comparison...

Yesterday's ukmo 12z 144

This morning at 120...

Edited December 5, 2020 by northwestsnow