Model Output Discussion - 18z 31/10/15 onwards

[Liam J]

It is too early for the meto to throw it's weight behind a cold spell that is two weeks away. They are always cautious when it comes to forecasting cold spells. I expect them to come on board in the next couple of days. A cold spell in 2 weeks is just about nailed on imo. GFS consistent on this from 360 hours out, now into the 10 day range. Oh, the second reason - cold spells very often follow persistent foggy spells a couple of weeks later. If people haven't noticed this phenomenom over the years then they clearly haven't been paying enough attention

The Met Office may not come on board at all, for a start we do not know what their in house models are currently predicting, and I don't think the Met Office use GFS data to produce forecasts (I may be wrong)... Nothing is ever nailed on at 2 weeks out either. 

[bluearmy]

Mean upper ridge beginning to show n Atlantic/Greenland in two weeks time.

From little acorns .........

[Methuselah]

Well, I'm in one of those locations where a NNW wind would normally 'deliver the goods', and I'm far from convinced by either the ECM or the GFS!

[blizzard81]

The Met Office may not come on board at all, for a start we do not know what their in house models are currently predicting, and I don't think the Met Office use GFS data to produce forecasts (I may be wrong)... Nothing is ever nailed on at 2 weeks out either.

My post was with a pinch of tongue in cheek only a pinch though. I believe we will experience a cold spell in a couple of weeks.

[knocker]

The GEFS 6-10 anomaly has the low pressure over the pole and Greenland with mid Atlantic trough and HP to the SE of the UK so still much of a N/S split.

All change on the 11-15 with ridging over Greenland and the trough over the UK bringing unsettled cooler weather to all with average temps.

http://www.tropicaltidbits.com/

Edited November 4, 2015 by knocker

[london and south east kent]

Hi all The cold is still there to night on gfs lets see if ecm sees this in next few days I can't see us being in a strong westerly later November we'll see.The meto might need change there further ahead forecasts to a more colder note..

hi all gfs still going with cold northerly for mid November getting interesting ..

[blizzard81]

hi all gfs still going with cold northerly for mid November getting interesting ..

Indeed, the GFS is very good at picking up trends at 2 weeks plus, especially when it involves amplification in the vicinity of Greenland and north east Canada

[Methuselah]

Indeed, the GFS is very good at picking up trends at 2 weeks plus, especially when it involves amplification in the vicinity of Greenland and north east Canada

Aye. Especially those that don't exist?

[pip22]

Looks like the cold snap I mentioned this morning has actually upgraded ten-fold. Nice.

 

The cold snap is gone from a blink or you miss it affair to a more prolong one.

Edited November 4, 2015 by pip22

[blizzard81]

Aye. Especially those that don't exist?

Ha ha In terms of amplification to our north west, it is nearly always the ECM that spots the false trends - but don't get me started on that one

Edited November 4, 2015 by blizzard81

[Captain Shortwave]

WAA is pumping up into Labrador and above at day 10, once that low pressure in the Atlantic sweeps though day 11/12 ish it would open the Door to a Northerly with heights up around Greenland.

I will add, I'm by know means knowledgable in this field - so this is my interpretation and prob Not anywhere close to being correct.

The trough could very well sharpen up leaving us in a southerly flow, it could also push eastwards, or we could get something in-between with low pressure sitting over the UK. The joys of looking at the extended range 

 

At least we have some agreement developing with regards to that Newfoundland high actually developing (though at that range it could move or disappear).

ECM

 

GFS

Edited November 4, 2015 by Captain shortwave

[blizzard81]

The trough could very well sharpen up leaving us in a southerly flow, it could also push eastwards, or we could get something in-between with low pressure sitting over the UK. The joys of looking at the extended range 

Trends only for me at that range. The specifics can wait for the 2 to 3 day range.

[MR EXTREMES]

I think that's unfair knocker I've seen the models and from tonight's outputs anything is possible.

[BLAST FROM THE PAST]

I think ECM holds some interest going forward from day 10, doesn't really back up the GFS which is as expected.

 

It does.   I've been posting mainly in the banter thread but have been outing the potential change for second half onwards.  I think this is now an interesting quote from Fergie

 

fergieweather, on 03 Nov 2015 - 21:30, said:

 

...albeit 12z EC clusters highlights some much more vigorous cyclonic outcomes possible from mid-month (out to T+360), & not solely tracking off up to the NW of UK.

 

 

Momentum seems to be building

 

BFTP

Edited November 4, 2015 by BLAST FROM THE PAST

[blizzard81]

Mean upper ridge beginning to show n Atlantic/Greenland in two weeks time.

From little acorns .........

Hi BA. Could you please let me know what the ECM blue control run is showing on the 12z. I remember you had access to this last winter.

[knocker]

Tonight's NOAA is not in agreement with the GEFS. No Greenland ridging and a much flatter trough Iceland so with the HP to the SE still having some influence still looking at westerly streamlines and a N/S split. (Quite high confidence)

 

[Cloud 10]

GEFS (P) control run also going for the Greenland high opton.

 

[Paul]

Very soon we'll have a post online explaining to everyone what is and isn't reasonable in the model thread, but just for now - I think those engaging in silly tit-for-tat stuff need to expect that's going to be on the list of things not to do, so please stop. 

[BLAST FROM THE PAST]

Actually Knocker looking through the ECM run up to t240 I read it that it would lead on towards a similar scenario that Gfs comes up with, a reasonable assumption.  However, whether that comes off is another kettle of fish and your NOAA charts show that required caution for sure.

 

BFTP

Edited November 4, 2015 by BLAST FROM THE PAST

[Ravelin]

Sheesh, one sniff of a pattern change and bun fights have broken out all over the place. Let's be realistic here, it 10 days at a minimum before anything substantially colder is even on the cards, if the GFS turns out to be onto something.

I've only been watching models, reading threads and occasionally posting for a couple of years. Much less time than most. What I have learned though that is that I don't trust the models at 10 days out, be that the operationals, the ensembles, the anomalies or the NOAA.

Let's wait and see. What we have at the moment is 'interesting', nothing more.

It's going to be a long winter on here at this rate!

[bluearmy]

Tonight's NOAA is not in agreement with the GEFS. No Greenland ridging and a much flatter trough Iceland so with the HP to the SE still having some influence still looking at westerly streamlines and a N/S split. (Quite high confidence)

The mean ridge only becomes noticeable towards the end of the gefs run (day 13 onwards). The 8/14 day average output is hardly going to pick that up knocks?

[knocker]

The mean ridge only becomes noticeable towards the end of the gefs run (day 13 onwards). The 8/14 day average output is hardly going to pick that up knocks?

 

Granted but the ext ecm, although it does have some positive heights Labrador strait, does keep some positivity to  the SE of the UK and makes nowhere near as much of the trough to the NW leading to a much more benign westerly flow, My contention is just that given all of the available evidence the hysteria surrounding one gfs run is not warranted as yet.

Edited November 4, 2015 by knocker

[Ali1977]

Early on but this run looks like it could bring another cold run...More WAA in Canada at T144 than the 12z....we'll see!!!

[Mucka]

The mean ridge only becomes noticeable towards the end of the gefs run (day 13 onwards). The 8/14 day average output is hardly going to pick that up knocks?

 

I think that is right Blue and on top of that the signal itself is quite muted at the moment, it will take a couple of days before any mean anomaly begins to appear even if GFS is onto something.

It has been suggesting a possible post month Northerly outbreak for some time but more by way of chilly/cold snap from a transient Northerly than cold spell.

We have seen some hints of MLB but no HLB at all so a cold spell proper looks unlikely at the moment but then again things could change quite quickly if we can get MLB in place to start with.

 

18z rolling out and out to the mid term it looks a little more amplified upstream so hopefully it will at least show a Northerly again.

[johnholmes]

The mean ridge only becomes noticeable towards the end of the gefs run (day 13 onwards). The 8/14 day average output is hardly going to pick that up knocks?

 

And as such has a pretty low probability of being anything more than, IF it verifies, a 24 perhaps 48 hours burst of Pm air. Until the anomaly charts start to solidly show such development then what most folk on here want, lengthy cold is unlikely in my view.