Model output discussion 24/01/21

[Allseasons-Si]

The gfs at 174,this could slide nearer the time.

Edited January 24, 2021 by Allseasons-si

[Griff]

Even at 126, who are you going to believe, gfs or parallel?  

[Gowon]

Arperge still going for the slider Wednesday into Thursday.

[nick sussex]

Some agreement on the overall pattern to day 6 . After a lot of huffing and puffing with shortwave energy flying all over the place .

A wedge of heights to the nw ahead of a low in Atlantic moving east .

If the upstream low disrupts favourably some snow as that happens .

The UKMO annoyingly leaves a shortwave to the west of the UK ready to phase which we don’t want .

At this point I think we need a bit more sharpness to the upstream low.

[Griff]

29 minutes ago, Griff said:

"I will not get carried away by slight amplification towards Iceland at 78 hours on GFS"

"I will not get carried away by slight amplification towards Iceland at 78 hours on GFS"

"I will not get carried away by slight amplification towards Iceland at 78 hours on GFS"

For balance gem at 78 is also similarly more amplified... 

[Battleground Snow]

I'm a bit sceptical of the Ukmo 144 charts atm, never seem to verify, hopefully ECM backs it up.

 

 

 

[Allseasons-Si]

8 minutes ago, northwestsnow said:

Need to see 850s...

 

Getting colder from the NE i would of thought.

[Ice Day]

10 minutes ago, northwestsnow said:

Need to see 850s...

 

There you go NWS

I would say pretty decent and getting better!?

Edit - Si beat me to it!!!

Edited January 24, 2021 by Ice Day

[Allseasons-Si]

The GEM is an upgrade at just 126...

 

[Froze were the Days]

17 minutes ago, northwestsnow said:

UKMO 144 looks an Easterly...?

Cyclonic easterly = not very cold

[chris55]

7 minutes ago, Notty said:

GFS T+138

06z

12z

Not very alike !

This current pattern is essentially rendering the models useless IMO (at least at a UK level.)

Within the colder flow it took about 10 incorrect runs to finally pin down todays snowfall in the south at a range of about 36 hours.

The trouble is how each and every approaching Atlantic low will interact with heights to the north, and with the polar front boundary being much further south than usual due to the SSW, the interactions/phasing (or not) of these lows and how far they do or don't push north is not the kind of thing you can predict accurately at day 3-4-5 plus!  But that's seems to be the key to the local pattern for the next few weeks.

Unless we get a clear signal of a big Scandi high or the like then we might be chasing the pattern for a few days yet.

[Griff]

Just now, Allseasons-si said:

The GEM is an upgrade at just 126...

 

Yes, has my attention, wondering where this might end up... Watching

[Griff]

1 minute ago, Griff said:

Yes, has my attention, wondering where this might end up... Watching

Don't spoil it Atlantic 

Edited January 24, 2021 by Griff

[nick sussex]

If you end up with an Atlantic trough v wedge battle , you can make the case for a significant amount of snow to fall in favoured areas if we see continued attempts for the Atlantic to move in which continue to disrupt energy se .

Eventually you will get a winner , let’s hope it’s a cold win with a high pressure cell near Scandi finally saying hasta la vista to the Atlantic . Failure isn’t an option , cards need to fall kindly .

As Picard says make it so ! 

[Allseasons-Si]

The latest from the GEM at 144

i am loving these upgrades this afternoon, I did miss out on the snow today but i am also glad that other folk got it this time and maybe more to follow

[Ice Day]

4 minutes ago, Allseasons-si said:

The GEM is an upgrade at just 126...

 

It's looking really good at 162, north easterly

  

[Singularity]

Well, here's how I currently see it:

Tamara was right to caution yesterday that the models may be going too far with the duration of enhanced convection in the West Pacific - and hence the amount of effect on weather patterns in our vicinity.

I wonder, though, if the models are really seeing all that much influence. We're seeing the polar jet stream being modelled to regain some strength by next weekend after a pause later this week. That suggests AAM not rising much, if at all.

So, it could well be that there's a lot being thrown against the cold air close to our north and northeast.

...but that's not to say that a trough won't disrupt, with a low slipping down toward Central Europe, providing some of us with a notable snow event along the way.

The more vigorous the Atlantic, the more dramatic any potential snowstorm event - but also, the lower the probability of that occurring over the UK instead to our east. So it's a balancing act that we can only guess the outcome of at this stage.

Longer-term, it's unclear whether the West Pacific convection will remain influential enough to send AAM climbing significantly. I'd not bet on it myself but who knows - the oceanic component to the La Nina is expected to gradually ease off, after all. The disrupted polar vortex should help us to make something of whatever opportunities arise next month. We may not see a persistently cold month but the colder episodes could be at least as marked as they've been in January - maybe more so in the south.

[Captain Shortwave]

How’s our luck, what a chart this is....

A band of rain in the south with cold air possibly turning this to snow with a very cold north easterly following. The best solution of the bunch so far but not outside the range of possibility with that earlier wedge of heights.

[Penicuikblizzard]

1 minute ago, Ice Day said:

It's looking really good at 162, north easterly

  

Is the GEM a decent model compared to the others

[Griff]

GFS in FI just for fun

[nick sussex]

4 minutes ago, Captain Shortwave said:

How’s our luck, what a chart this is....

A band of rain in the south with cold air possibly turning this to snow with a very cold north easterly following. The best solution of the bunch so far but not outside the range of possibility with that earlier wedge of heights.

The key thing is that shortwave west of Iceland phases favourably with the troughing and gets pulled nw . 

 

[Griff]

Tease of the day goes to... 

[Ice Day]

3 minutes ago, Penicuikblizzard said:

Is the GEM a decent model compared to the others

Only when it's showing snow!

Actually, it's been mentioned a few times on here recently that it's been performing well of late (I think it has had a recent upgrade).  I recall @Vikos showing the stats where it was outperforming the GFS?  

[Tim Bland]

Yes, GEM more often than not outperforms GFS and is usually similar to ECM. This was the earlier run so it may be a signal. Also similar to ECM from earlier 

[winterof79]

Anyone want to spot the GFS with its westward bias