Model Output Discussion 01/09/17

[bluearmy]

16 minutes ago, Heekster said:

How often do these west based NAO's happen ? 

Generally when nw Europe has been modelled  a cold period more than a week away  ...............

[Daniel*]

A right bulls up I’d take its forecast of a blowtorch +NAO winter lightly at this stage.. 

 

[Methuselah]

It seems to me that the synoptic output contains more useful information than the value of the NAO? 

[bluearmy]

12 minutes ago, Daniel* said:

A right bulls up I’d take its forecast of a blowtorch +NAO winter lightly at this stage.. 

 

Don't tell Crewe - he keeps quoting the ever reliable cfsv2 ..............

[northwestsnow]

2 minutes ago, bluearmy said:

Don't tell Crewe - he keeps quoting the ever reliable cfsv2 ..............

I think it just confirms or re-enforces my personal doubts about the LRF- not just this model i might add.

Bit disappointed there is no update from Exeter today- would have been nice to see if their thoughts on second half of November have changed at all.

So, eyes down for the 12zs- as Nick S alluded to earlier, EC gets very very close to the dreaded west based -NAO on its 00z run,would like to see that little trend vanish rapidly.

[MP-R]

41 minutes ago, Heekster said:

How often do these west based NAO's happen ? 

Not overly frequently, but seem to happen, as bluearmy pointed out, especially when our part of Europe is forecast to be cold. One of the most stark examples was February 2010 which could've been considerably colder had low pressure been in a better place. Needless to say, on that occasion, there was already enough cold in place and closeby that snow was still achieved albeit marginally. Fortunately, I'm not seeing that as so much of a problem in today's runs.

[Daniel*]

19 minutes ago, northwestsnow said:

I think it just confirms or re-enforces my personal doubts about the LRF- not just this model i might add.

Bit disappointed there is no update from Exeter today- would have been nice to see if their thoughts on second half of November have changed at all.

So, eyes down for the 12zs- as Nick S alluded to earlier, EC gets very very close to the dreaded west based -NAO on its 00z run,would like to see that little trend vanish rapidly.

http://www.metoffice.gov.uk/public/weather/forecast

It reinforces my thoughts of CFS > Can’t Forecast ****

Rather wintry sounding - roll on the 12z 

[Man With Beard]

What a fascinating model watching period! I mentioned yesterday having no idea beyond T120 and it looks like the models were listening to me, especially the UKMO!

Both GEFS and ECM ensembles are very confused by T144. It can only mean high pressure is getting into unusual places!

By T240, both mean charts show intriguing slack heights all over the N Atlantic. The EC clusters show the options behind the mean:

My attention is drawn not only to the heights still trying to get to Greenland, but an increasing number of runs lowering heights in Europe once again.

Gotta keep watching!

[northwestsnow]

Meto update sounds very much like the gfs6z run ...

Very blocked..and perhaps snow to low levels in the north next weekend..which suprises me greatly as all the NWP evidence i have seen does not suggest that at all!!

Perhaps the 12zs will be an upgrade..

Edited November 12, 2017 by northwestsnow

[northwestsnow]

4 minutes ago, Daniel* said:

http://www.metoffice.gov.uk/public/weather/forecast

It reinforces my thoughts of CFS > Can’t Forecast ****

Rather wintry sounding - roll on the 12z 

For the north esp thats a wintry update...dont know where the wintry showers to low levels in the north next weekend is coming from tho..

Edited November 12, 2017 by northwestsnow

[feb1991blizzard]

As I thought though, blocked but without cold uppers and the window of opportunity ends in Early Dec as the nina kicks in, just shows you that when no ensemble members model any cold uppers but nearly all model blocking, you cant just bury your head in the sand and trot out the over-used phrase 'get the blocking in, then the cold will follow', it doesn't happen like that, that's the reason this time last year that the MO never went for anything cold enough to produce widespread low level snow, Ensembles are for this very purpose, assimilate many different scenarios and these variations include uppers too, so if hardly any runs with cold uppers are shown, its probably because cold uppers aint gonna happen.

[johnholmes]

11 minutes ago, feb1991blizzard said:

As I thought though, blocked but without cold uppers and the window of opportunity ends in Early Dec as the nina kicks in, just shows you that when no ensemble members model any cold uppers but nearly all model blocking, you cant just bury your head in the sand and trot out the over-used phrase 'get the blocking in, then the cold will follow', it doesn't happen like that, that's the reason this time last year that the MO never went for anything cold enough to produce widespread low level snow, Ensembles are for this very purpose, assimilate many different scenarios and these variations include uppers too, so if hardly any runs with cold uppers are shown, its probably because cold uppers aint gonna happen.

I am not sure what you mean but why not we transfer to the correct thread, which is

The Met O 6-15 or 15-30 day outlook,

I'll be on there if you want to see my post

[cheshire snow]

6 minutes ago, feb1991blizzard said:

As I thought though, blocked but without cold uppers and the window of opportunity ends in Early Dec as the nina kicks in, just shows you that when no ensemble members model any cold uppers but nearly all model blocking, you cant just bury your head in the sand and trot out the over-used phrase 'get the blocking in, then the cold will follow', it doesn't happen like that, that's the reason this time last year that the MO never went for anything cold enough to produce widespread low level snow, Ensembles are for this very purpose, assimilate many different scenarios and these variations include uppers too, so if hardly any runs with cold uppers are shown, its probably because cold uppers aint gonna happen.

 Hi Feb

 At this stage i get reaaly confused with the whole cold uppers debate,I was always under the inpression that uppers of around -5c can produce snowfall to low levels or am i totally missing something here?

 seems to be an obsesion within certain ranks that unless we have uppers of -10c or lower then thats it game over.

Just as an after thought please PM  if you want to reply save sending this thread of topic

Thanks

C.S

[MR EXTREMES]

13 minutes ago, feb1991blizzard said:

As I thought though, blocked but without cold uppers and the window of opportunity ends in Early Dec as the nina kicks in, just shows you that when no ensemble members model any cold uppers but nearly all model blocking, you cant just bury your head in the sand and trot out the over-used phrase 'get the blocking in, then the cold will follow', it doesn't happen like that, that's the reason this time last year that the MO never went for anything cold enough to produce widespread low level snow, Ensembles are for this very purpose, assimilate many different scenarios and these variations include uppers too, so if hardly any runs with cold uppers are shown, its probably because cold uppers aint gonna happen.

The met office are going for blocked and cold and that's a very unusual stance by the ukmo.

They seem keen on jet dropping south.

With blocked pattern they rarely use the term blocking.

Either way it's pretty nippy today best feel to autumn down here for a fair few years.

I think the micro details will come once blocking is in place 

[Scandinavian High.]

23/11/2017 if this comes of that’s a wintry outlook with wintery showers and not just for the north and look at that cold to the north east for time of year where in a very good period I don’t understand all the down beat in here...

[Snowy L]

Now would be a great time for Fergieweather to pop in and tell us what the MOGREPS is showing. 

[blizzard81]

53 minutes ago, northwestsnow said:

Meto update sounds very much like the gfs6z run ...

Very blocked..and perhaps snow to low levels in the north next weekend..which suprises me greatly as all the NWP evidence i have seen does not suggest that at all!!

Perhaps the 12zs will be an upgrade..

Don't like the last sentence though. 

[Dennis]

setup for second part is very important - novembercold 

[Frosty.]

With an increasingly blocked and cold mid / longer range outlook being favoured, coldies  should be in dreamland..I know I am!

If all goes well, next weekend and the following week will bring our first of hopefully many wintry outbreaks during the next 4 months.☺

[Man With Beard]

@feb1991blizzard I think your comments were justified when it came to this first attempt at a northerly between T144-T216 - it needed an extreme northerly to get snow-bearing Arctic cold, and was the outside bet all along.

However, have you seen the GEFS 06Z?? By T300, they're onto a second wave from the north. I counted 8 out of 21 ensembles that were cold enough for lowland snow. Yes it's too far out to make much of, but what it tells me is that if heights get stuck to the NW as many ensemble members have it, then a cooling process will begin over N Europe, and the potential will absolutely be there by the end of week 2.

And, of course, it's never an easy shoe in to get snow to the UK, is it! I can list 2 events in 30 years that were an easy snow forecast beyond D6: 1991 and 2010. 

So week 1 snow potential at low levels, no, week 2 however, yes.

[Mucka]

Surprising how all over the map UKMO has been recently.

A bit closer to GFS this evening as far as trough placement goes (day 5 though still shallower) but still chopping and changing upstream too and different ideas there.

 

 

 

[tight isobar]

Modeling' continues the cool eventualy colder....possible 'notable later on.

Turning attentions aways for a sec..on atlantic/blocking into greenland..n/e canadian region'

The north pacific ridge continues to grasp my eye...and could be a key player in both sustained perplexion on the vortex and any prolongment in keeping HLB on the formentioned atlantic waa.

[northwestsnow]

 

UKMO looks interesting at 144- but i still cant post todays charts!!!

Edited November 12, 2017 by northwestsnow

[swfc]

Such differences on run to run to run on gfs regarding low pressure exiting thw esb leave imo anything past 120 hrs up in tge air

 

 

 

On 11/11/2017 at 13:40, Jonan92 said:

 

Edited November 12, 2017 by swfc

[Mucka]

I'll just throw this out there as a mini ramp as I sip on my half full glass of 50% proof optimism while reading the Daily Upbeat through my rose tinted spectacles.

 

GFS (day 7/8) is not that far away, with regard to synoptic if correct, from giving a snow event for Northern parts.

The pattern only needs be backed West and the trough sharpened to have sub -5 850's in place when (if) we get an Atlantic trough disrupting SE across Southern England as GFS has been recently modelling.

 It isn't far fetched so long as GFS has the pattern nailed - which may be the far fetched part