Model output discussion - late November

[StretfordEnd1996]

1 minute ago, WXHerts said:

 While UKMO appears to differ significantly to ICON,  GFS at 120h looks very similar indeed...!

I wouldn't say the UKMO differs 'significantly' - I just don't think it goes out far enough yet to paint the similar picture for D7/8 (D7-8 were the 'focal point' of the ICON where the HP proper pushes to the NW/Greenland) 

In other words had the UKMO gone a little further we could well have seen that second HP push towards a similar location to the ICON - it's just a day or so later

(I am a novice by the way so don't take me too seriously! But I don't think the UKMO is a complete contrast to the ICON).

Not that I particularly would chose the ICON as the most reliable in the world ..

[WxHerts]

7 minutes ago, StretfordEnd1996 said:

I wouldn't say the UKMO differs 'significantly' - I just don't think it goes out far enough yet to paint the similar picture for D7/8 (D7-8 were the 'focal point' of the ICON where the HP proper pushes to the NW/Greenland) 

In other words had the UKMO gone a little further we could well have seen that second HP push towards a similar location to the ICON - it's just a day or so later

(I am a novice by the way so don't take me too seriously! But I don't think the UKMO is a complete contrast to the ICON).

Not that I particularly would chose the ICON as the most reliable in the world ..

 I agree that UKMO would likely be good if it were to continue on a few days. Compared to ICON and GFS at 144h however, it appears be the odd one out - UKMO flattest of the lot.   

Edited November 23, 2019 by WXHerts

[swfc]

At 144 hrs both ukmo and GFS look pretty similar imo.icon altho looks on its own atm

Edited November 23, 2019 by swfc

[StretfordEnd1996]

Yes not sure if I'm liking the progression of the GFS as by D7 the HP still isn't really doing much and is staying in a bit of a flatter position - will it push further North eventually?

[knocker]

Quite a nasty looking low midweek

[WxHerts]

Just now, StretfordEnd1996 said:

Yes not sure if I'm liking the progression of the GFS as by D7 the HP still isn't really doing much and is staying in a bit of a flatter position - will it push further North eventually?

Probably not, short term differences most important to take note of at the moment though. A definite improvement by d5, hopefully GEFS reflect this and then ECM later

[swfc]

3 minutes ago, StretfordEnd1996 said:

Yes not sure if I'm liking the progression of the GFS as by D7 the HP still isn't really doing much and is staying in a bit of a flatter position - will it push further North eventually?

Nope,can't go anywhere and collapses 

[StretfordEnd1996]

And yes, it is true - it doesn't quite happen in the way a lot of us would want it to on the GFS - and is definitely a contrast to the ICON

Let's hope its sisters in the GEFS ensembles show that it's off the mark a little!

I wouldn't be surprised if its one of the more milder members to be honest as it really does bring that through quite quickly but we'll see. 

 

[swfc]

I think looking at today's output so far it looks a transient Atlantic ridge and the PV to the north western quadrant strengthening .it could change with the ridging pushing further north but it could also go the other way.hopefully some dry weather either way will do

[Methuselah]

It does look like, following a relatively brief incursion of colder air (and always assuming the GFS is in the right ballpark?) warmer grot will eventually push the cold aside, as the Eurotrash HP takes over...?

    

That said, the PNJ is hardly flat...

[IDO]

Subtle changes upstream in the Pacific Basin with respect to the interaction of highs, cut-off lows and trough'ing, the knock on effect is more forcing to the pattern on the 12z run:

6z>> 12z>> 

So the heights fail to build in the Atlantic due to the flabby US ridge/trough combo compared to the 06z. It looks like as we enter December, the first week may start milder and drier, turning wetter and cooler, with a FI flat and pretty zonal, back to a N'Westerly flow (usual caveats).

Now it has found one of the worse case scenarios, the GFS FI is bound to start showing consistency!

[SMU]

GEM follows the ICON & UKMO & is the coldest for the UK at 156 ( @850 ) so thats 3/3 have dumped the GFS solution yet all the comments will be about the GFS...

[swfc]

1 minute ago, Steve Murr said:

GEM follows the ICON & UKMO & is the coldest for the UK at 156 ( @850 ) so thats 3/3 have dumped the GFS solution yet all the comments will be about the GFS...

Just commenting on the 12z GFS.imo the ukmo at 144 hrs looks similar to the GFS 12z.i didn't realise icon and gem were credible.also ECM earlier today was average

[jules216]

12 hours ago, northwestsnow said:

Dews across Europe show the Mid Atlantic high doing its job and allowing colder air to spill down from the north.

Should put a smile  @jules216 face

@northwestsnow it looks lot more seasonal finally, if I have to cherry pick a frame from 12Z then this would be nice. Looks like 30.11 to hopefully at least 5.12 will be a window for a cold snap

[SMU]

6 minutes ago, swfc said:

Just commenting on the 12z GFS.imo the ukmo at 144 hrs looks similar to the GFS 12z.i didn't realise icon and gem were credible.also ECM earlier today was average

There okish models - ICON did well in 2018 beast- will still need support from ECM

I think its the reference that all models ( exc GFS ) have moved West.

Noting upstream GFS mean V 06z slower like the ICON was - very clear here 12z first will mean the runs will move another increment to a colder solution....

Edited November 23, 2019 by Steve Murr

[StretfordEnd1996]

3 minutes ago, Steve Murr said:

There okish models - ICON did well in 2018 beast- will still need support from ECM

I think its the reference that all models ( exc GFS ) have moved West.

Noting upstream GFS mean V 06z slower like the ICON was - very clear here 12z first will mean the runs will move another increment to a colder solution....

Absolutely and I think the biggest issue is that there simply aren't any models that will ever be 100% especially for our country, and I understand that there are a few models today such as the ICON and GEM that are showing a more favourable solution but the GFS is always going to be commented on too as it has for whatever reason got a bigger name and a lot of people do consider it the most worthwhile .. let's see what happens.

I don't think anyone can honestly look at that ICON and think that's definitely the most probable solution - 

[knocker]

20 minutes ago, IDO said:

Subtle changes upstream in the Pacific Basin with respect to the interaction of highs, cut-off lows and trough'ing, the knock on effect is more forcing to the pattern on the 12z run:

 

 

I'm not sure this is what you mean but it does initiate the pattern change downstream according to the GEFS

 

Edited November 23, 2019 by knocker

[SMU]

Just now, StretfordEnd1996 said:

Absolutely and I think the biggest issue is that there simply aren't any models that will ever be 100% especially for our country, and I understand that there are a few models today such as the ICON and GEM that are showing a more favourable solution but the GFS is always going to be commented on too as it has for whatever reason got a bigger name and a lot of people do consider it the most worthwhile .. let's see what happens.

I don't think anyone can honestly look at that ICON and think that's definitely the most probable solution - 

No thats right - What the idea is as alluded to earlier is to build a ridge at 144 ahead of the low that gets far enough North to creat a cut off wedge so the trailing Energy from the main US low is ushered SE rather than NE ...

The GEM has the idea ( like the 00z ECM ) 

ICON is the most extreme westerly solution so probably is far left as is the GFS far right...

[SMU]

Best GFS mean coming up to date -

Will add the comparison to yesterdays countdown.....

[Tim Bland]

Nice northerly setting up at day 9 on the GEM 

[SMU]

So run 4 of the GFS mean countdown annotated- We are down to 162 Now

* NOTE * The emphasis of the ridging now beginning to edge west of the SW tip of Greenland which is the cut off point-

[Snowyowl9]

ICON.

Another low slap bang on top probably end up further south to this.From december 1st looks very cold outlook

.

[StretfordEnd1996]

12 minutes ago, Steve Murr said:

No thats right - What the idea is as alluded to earlier is to build a ridge at 144 ahead of the low that gets far enough North to creat a cut off wedge so the trailing Energy from the main US low is ushered SE rather than NE ...

The GEM has the idea ( like the 00z ECM ) 

ICON is the most extreme westerly solution so probably is far left as is the GFS far right...

Thanks for this.

I suppose in a way if it was the other way around and the GFS was showing a perfect scenario compared to a much more milder UKMO and GEM, I'd certainly own up to dismissing the latter two and trying to find as many reasons as possible as to why the GFS is right.. but hey this what it's all about at this time of year and it's purely because our shores are so subject to being extremely difficult to forecast! 

[Jordan S]

1 hour ago, WXHerts said:

 Very big differences between UKMO and ICON at 144h, UKMO lacking WAA.  

Which highlights the uncertainty very well and shows not to pin "hopes" into one cold run verifying.

[ArHu3]

51 minutes ago, Steve Murr said:

There okish models - ICON did well in 2018 beast- will still need support from ECM

I think its the reference that all models ( exc GFS ) have moved West.

Noting upstream GFS mean V 06z slower like the ICON was - very clear here 12z first will mean the runs will move another increment to a colder solution....

Gem comes out as 2nd best actually 

 

https://www.ecmwf.int/en/forecasts/charts/catalogue/plwww_3m_ens_tigge_wp_mean?facets=Range,Medium (15 days)%3BType,Verification&time=2019092300¶meter=24h precipitation&score=CRPSS&area=Extra-tropics