Model Output Discussion 01/09/17

[Allseasons-Si]

Latest NAO/AO,keep falling

had to edit cos the ones i originally posted seems to be the 25 th ones,that's better.

Edited November 26, 2017 by Allseasons-si

[london-snow]

7 minutes ago, terrier said:

Not liking the look of the 18z so far 

Really please explain..

[johnholmes]

1 hour ago, Bring Back1962-63 said:

 

Just to drop in the anomaly charts I use for the same day and all 3 suggested a cold spell on the way, in my view anyway. Not sure I can get them to copy in her but will try

Net wx example for sun 26 nov.doc

[Chris.]

looks a improvement to me.  Bigger cold above the UK.  Greenland high further west

 

[Met4Cast]

+78 and the GFS is still saying no to the UKMO. I think we can be pretty confident the UKMO will come kicking and screaming tomorrow morning

[bluearmy]

7 minutes ago, swilliam said:

It says in the text UKMO was tied 4th (i.e behind theses three).

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

[Cheshire Freeze]

2 minutes ago, bluearmy said:

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

Can clearly see the retrograde there. Atmosphere spinning in reverse!

[feb1991blizzard]

1 minute ago, bluearmy said:

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

It just shows you what we are up against, synoptically that's on a par, if not even more extensively blocked than the 17th Dec 2010 chart, yet still doesn't even threaten the -10c line.

[Chris.]

-9 uppers covering majority of UK by +84

 

[tight isobar]

Gfs keeps turning its back on waa to greenland..

As pv goes a tad into overdrive eastern-canada.

However' still looking v-good overall.

And aiming for waa pole heights meet!...

Is anybody confused!!?? Russian ridge cutting in also...

Pv pre-anniulation!

Edited November 26, 2017 by tight isobar

[swilliam]

2 minutes ago, bluearmy said:

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

Terrible grammar in the tweet - one reason why I rarely read tweets

[Cheshire Freeze]

1 minute ago, feb1991blizzard said:

It just shows you what we are up against, synoptically that's on a par, if not even more extensively blocked than the 17th Dec 2010 chart, yet still doesn't even threaten the -10c line.

That's what I was saying earlier Feb. The lack of truly cold uppers around the NH is pretty stark. 

[swfc]

4 minutes ago, bluearmy said:

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

Is that actually possible. Holy mother of god!!!

[Dancerwithwings]

4 minutes ago, bluearmy said:

Nope - the n American models were all tied for fourth 

incidentally, whilst it's still available, there can be few runs on a NH perspective as mesmerising as 12z gefs member 19

 

Did you see the anom Z500 - 384h.... Phew!!!

[Ice Day]

ECM and GFS absolutely identical at 96hrs. 

GFS

ECM

 

Looking like the UKMO is barking up the wrong tree on this occasion!

[SMU]

Looking at the ECM OP V the Means for the UK suggests that the solution offered by the OP in terms of deep low at 216 > 240 driving the 0c isotherm back over the UK is likely to be incorrect !

[feb1991blizzard]

1 minute ago, CreweCold said:

That's what I was saying earlier Feb. The lack of truly cold uppers around the NH is pretty stark. 

The thing is its exactly the same evolution as that aforementioned 2010 spell, a snap off of the PV and subsequent sending south of, although with this run, would you even call it a chunk of the PV, is it cold enough.

[bluearmy]

2 minutes ago, Dancerwithwings said:

Did you see the anom Z500 - 384h.... Phew!!!

Hysterical

 

[Nick F]

45 minutes ago, lorenzo said:

All in - tremendous model viewing, and something we have not had to enjoy for a few years. Lets make the commentary on said viewing as cool as it can be..

certainly not run-of-the-mill standard fare for late November. My interest is not so much in this coming week's weather, which looks cold but mostly dry away from coastal areas. I'm more fascinated in watching the bigger picture unfold for the end of November and ahead for the first few weeks of December.

Having seen the extended EPS for the last several runs, blocking looks to remain in place near Greenland for a protracted period, of 10-15 days at least lasting well into early December. That is a big plus with regards to keeping the flow across the UK from a cold direction.

Upstream, troughing stretching from Siberia to Alaska above ridging over SE Asia will continue to drive a strong east Pacific jet which extends its strong zonal flow energy over N America, keeping cold air bottled up over N Canada and driving a strong jet over the top of the Greenland block. This energy tending to perhaps flatten the N Atlantic/ S greenland ridge at times to allow some troughing to extend SE towards the UK, bringing surface lows with it. This pattern upstream looks to continue for the next 10 days at least.

However, in early December, a pattern change looks to take place upstream over the N Pacific, perhaps in the second week, where the strong east Asian/East Pacific looks to weaken, which will allow a long-wave ridge to form along or off the west coast of N America. We then end of with a three-prong ridge attack towards the pole in the trop = NE Pac/Greenland/W Russia ...

... which will surely put pressure through wave breaking on the polar vortex, certainly potential for cross polar ridging which maybe why the AO forecasts indices are nose-diving in early December.

All this while the MJO is forecast to remain weak, with little influence on the northern hemispheric patterns for the foreseeable.

Edited November 26, 2017 by Nick F

[stewfox]

1 hour ago, Bring Back1962-63 said:

MODEL VERIFICATION

There is always a lot of disagreement on here as to which model has performed better or worse compared to another. This has been strongly in evidence again today. 

 

Nps up on who performed well or badly, remember that the evidence is available!!! 

Great if we had all the stats

Would be great when someone says ECM handles these situation badly . or GFS tends to back the UKMO in these situations or GFS is always too eager to show over amplification we can refer to a link

ie what a load of B*****  it last handle this situation badly on jan 23rd 1897  see here www.forumstats.com

 

Edited November 26, 2017 by stewfox

[lorenzo]

What time do the ens via Iceland update on this index ?

http://brunnur.vedur.is/kort/ec-ens/2017/11/26/

 

[Ice Day]

At 144 and still the GFS and ECM are showing very similar evolution....

GFS

ECM

It looks like we've nailed the next 6 days, where do we go next???

Edit - heights looking better into Greenland at 150.

Edited November 26, 2017 by Ice Day

[swfc]

Well whatever happens on the gfs 18z the atlantic isn't moving anything our way with that block!!!

[feb1991blizzard]

7 minutes ago, lorenzo said:

What time do the ens via Iceland update on this index ?

http://brunnur.vedur.is/kort/ec-ens/2017/11/26/

 

Everything (including clusters) should be updated by 1031pm.

[Allseasons-Si]

Another good run i feel coming up

gfs18z /ecm 12z at 144