Model Output Discussion - New Year and Beyond

[Battleground Snow]

Gfs finally backed down to the other models at 120.

Really poor performance 

[northwestsnow]

144 

UKMO / GFS

[cold snap]

24 hour toppler.

 

 

[Ali1977]

2 minutes ago, northwestsnow said:

144 

UKMO / GFS

UKMO looks much better, but even by T168 the GFS looks to be prepping a reload with the Labrador area building the heights 

Edited January 9, 2023 by Ali1977

[Eagle Eye]

1 hour ago, minus10 said:

Hi Eagle Eye, can i ask you a question...the Global wind Oscillation chart looks similar to the MJO chart...its not though is it? Presumably phases 6-8 associated with colder weather?

Also, PNA?...AL (Aleutian low?)

AL ?

Still learning so i thought i'd ask the proff...

   

 

Lol, sorry it took me so long to reply, did half of it in lesson shhh.

PNA is the Pacific-North American area (well actually its the Pacific-North American Pattern but I'm lazy)

The GWO is a generalised chart

Phases 4-7 have increasing AAM

Phases 8-3 with decreasing AAM

5 through to 8 with colder patterns generally (support for mid to high latitude blocking via tropical forcing etc...)

Al - Aleutian Low

I also talk about the frictional torque balancing it out but what do I mean?

Well, as the mountain torque event happens, the upwards wave flux pushes outwards from the Tropics and the anomaly quickly becomes uniform between the latitudes and that leads to a frictional torque event that decreases the AAM. Generally its a pattern that repeats every couple weeks but can be shorter or longer (I.e a fairly persistent Ural Blovk with have cold on the other side of it so generally cold near the Himilayas quickly balancing out any +VE EAMT events as +VE events are warm air over the mountains and naturally the opposite is true for -VE events.) depending on the background signals. Both the SHAL (Siberian High - Aleutian Low) and the MJO affect the EAMT events though I'm not entirely sure how for each one.

[Battleground Snow]

Yes please gem,

Very snowy for the north, looks closer to the ukmo at 144 than the GFS too

[mountain shadow]

18 minutes ago, Battleground Snow said:

Gfs finally backed down to the other models at 120.

Really poor performance 

To be honest, the GFS operationals should be banned on here. They're a complete waste of space.

[The Northern Ramper]

1 minute ago, mountain shadow said:

To be honest, the GFS operationals should be banned on here. They're a complete waste of space.

I thought this myself yesterday, a complete waste of bandwidth.

[Battleground Snow]

1 minute ago, mountain shadow said:

To be honest, the GFS operationals should be banned on here. They're a complete waste of space.

It really is shocking, seeing the professionals openly criticize it too means something has gone badly wrong.

[Guest]

2 minutes ago, Battleground Snow said:

It really is shocking, seeing the professionals openly criticize it too means something has gone badly wrong.

Do the professionals feed back to the team responsible for the GFS model on just how badly it is performing?  How soon is it likely to be before something is done?

[Cold Winter Night]

Pretty powerful swing towards Atlantic amplification and trough dropping into Europe on GEM and GFS.
UKMO is even more amplified at 144h than those two.

UKMO 168h, interesting.

Edited January 9, 2023 by Cold Winter Night

[Battleground Snow]

Just now, Tidal Wave said:

Do the professionals feed back to the team responsible for the GFS model on just how badly it is performing?  How soon is it likely to be before something is done?

I imagine the team responsible for the model upgrade is urgently looking at a solution, whether that be rolling back to the old version or updating it in the near future.

 

[Battleground Snow]

2 minutes ago, Cold Winter Night said:

Pretty powerful swing towards Atlantic amplification and trough dropping into Europe on GEM and GFS.
UKMO is even more amplified at 144h than those two. Wondring what the 168h will look like.

Pretty cold.... Ukmo at 168, 

Would have been nice to see 192

[swebby]

20 minutes ago, Battleground Snow said:

Yes please gem,

Very snowy for the north, looks closer to the ukmo at 144 than the GFS too

Very windy for the South and the West!

[northwestsnow]

Was hoping for better at 168 ukmo if I'm honest

It would not be as good as GEM by day 8.

IMO..

Edited January 9, 2023 by northwestsnow

[Tim Bland]

All a bit meh..snow Scottish mountains and wintry showers higher ground, nothing exciting for the foreseeable for most 

[geordiekev]

33 minutes ago, Battleground Snow said:

Yes please gem,

Very snowy for the north, looks closer to the ukmo at 144 than the GFS too

Thats one helluva HP over Greenland even for the shelf, certainly looks similar to the 500 anomalies JH showed

[Daniel*]

GEM definitely pick of the bunch so far over to ECM…

[cheshire snow]

One for thd M4 south brigade shame its day 15

[swfc]

2 hours ago, northwestsnow said:

Exeter 24 to 48 Northerly   toppler and back to wind and rain thereafter ..

Let's see what the 12z's come up with ..

In all honesty I can't see anything with a decent cold spell 

[LRD]

22 minutes ago, northwestsnow said:

Was hoping for better at 168 ukmo if I'm honest

It would not be as good as GEM by day 8.

IMO..

Agree, it's an underwhelming UKMO. Met Office still not seeing anything of note for next week either unless you live on a Scottish mountain. 

GFS 12z has me shrugging my shoulders. An even worse run than its 6z op although the 6z ensembles weren't bad and, like the 6z, the 12z op looks pretty mild compared to the suite (only out to the 18th so far). But the control does follow it

GEM looks decent

[minus10]

59 minutes ago, Eagle Eye said:

Lol, sorry it took me so long to reply, did half of it in lesson shhh.

PNA is the Pacific-North American area (well actually its the Pacific-North American Pattern but I'm lazy)

The GWO is a generalised chart

Phases 4-7 have increasing AAM

Phases 8-3 with decreasing AAM

5 through to 8 with colder patterns generally (support for mid to high latitude blocking via tropical forcing etc...)

Al - Aleutian Low

I also talk about the frictional torque balancing it out but what do I mean?

Well, as the mountain torque event happens, the upwards wave flux pushes outwards from the Tropics and the anomaly quickly becomes uniform between the latitudes and that leads to a frictional torque event that decreases the AAM. Generally its a pattern that repeats every couple weeks but can be shorter or longer (I.e a fairly persistent Ural Blovk with have cold on the other side of it so generally cold near the Himilayas quickly balancing out any +VE EAMT events as +VE events are warm air over the mountains and naturally the opposite is true for -VE events.) depending on the background signals. Both the SHAL (Siberian High - Aleutian Low) and the MJO affect the EAMT events though I'm not entirely sure how for each one.

So positive EAMT events (warm air) have the effect of increasing AAM...whereas negative (cold air) events decrease AAM....hopefully i have understood that correctly. Many thanks mate...really appreciate your time...hope it didnt disrupt your lesson too much...havent looked at charts or thread but gfes 12z mean looks reasonable from the 16th so far...apologies if already posted..

[swfc]

23 minutes ago, geordiekev said:

Thats one helluva HP over Greenland even for the shelf, certainly looks similar to the 500 anomalies JH showed

in

It's not a strong high over Greenland tbh. Its more of an Atlantic ridge. The 1070mb reading isnt a true large strong geeenland  high

[BLAST FROM THE PAST]

5 hours ago, BLAST FROM THE PAST said:

Here’s one for fun.  Who’d think this 

would produce this

 

BFTP

 

I mean wow, this looks realistic , when you see this there’s something ‘interesting’ is brewing 

 

 

BFTP

Edited January 9, 2023 by BLAST FROM THE PAST

[Eagle Eye]

14 minutes ago, minus10 said:

So positive EAMT events (warm air) have the effect of increasing AAM...whereas negative (cold air) events decrease AAM....hopefully i have understood that correctly. 

Absolutely spot on, warm air over mountains = gain of torque and vice versa and no problem, I'd already completed the work in lesson anyway .