Model Output Discussion 26/10 2012 >

[Jeremy Shockey]

yes , as lloydyd points out ...this is a change in emphasis of the wording from the MetO today for the latter part of the period 21 Nov - 5 Dec

Towards the latter part of the period, there are some suggestions that conditions will turn drier with more in the way of sunshine, but also colder, with temperatures well below the seasonal average. This will give a greater risk of overnight frosts.

[Frosty.]

Where does it say this? I have read it and it doesn't say "well below" just "below the seasonal average".

EDIT: Just seen it at the end of the paragraph.

Yes I think it's odds on for a scandi/russian block to affect the uk towards the end of the month and early december.

Edited November 6, 2012 by Frosty039

[picog]

yes , as lloydyd points out ...this is a change in emphasis of the wording from the MetO today for the latter part of the period 21 Nov - 5 Dec

Towards the latter part of the period, there are some suggestions that conditions will turn drier with more in the way of sunshine, but also colder, with temperatures well below the seasonal average. This will give a greater risk of overnight frosts.

Does anyone know what data the Met Office are using to support the "well below average" prediction?

[No Balls Like Snow Balls]

Does anyone know what data the Met Office are using to support the "well below average" prediction?

They come on net weather and look at the model thread then decide from there

[bluearmy]

Does anyone know what data the Met Office are using to support the "well below average" prediction?

would normally be the ecm 32 day run updated each tues and fri

i note the 'well below average' is predicated on 'there are some suggestions'. hardly a concrete forecast!!

[Polar Maritime]

Does anyone know what data the Met Office are using to support the "well below average" prediction?

Probably there own new strat super computer to..

Edited November 6, 2012 by Polar Maritime

[Frosty.]

Probably there own new strat super computer to..

spot on, they have their own ens model which worked rather well when they forecast that severe wintry spell for late nov 2010 and throughout december 2010, i'm looking for some parallels in the current output and how it evolved back then and will post some comparison charts later. I liked the gfs 18z ens mean later output, the largest ridge I have ever seen from moscow to the azores, I would hazard a guess the cold further outlook is coming from the east rather than the north since there is no comment on snow showers, a mid lat high is probably an outside bet.

Edited November 6, 2012 by Frosty039

[Stu_London]

People should remember that the CET to the 1-6 November is about 5C, last year it was 12C for the same period. Whilst there are signs of it becoming less cold (yes we are 2.8C below the 1961-90 average, for the first 6 days) there are only short periods of what I would describe as mild weather showing on the models with the vast majority of our weather having at least returning Polar Maritime air in the mix.

With teleconnections also becoming interesting for the period just outside of the model output and the rather cold extended outlook from UKMO, there is plenty to make model watching interesting over the next couple of weeks.

[bluearmy]

Matt has just referenced the 32 dayr forecast in the strat thread. it continues to point at lower heights to our south and high ones to our north and northwest late nov/early dec. depending on where those pressure anomolys set up dictates whether we go cold/dry or cold/white or cool/wet. (if it verfies of course)

[cold snap]

matt hugo on twitter says ecm 32 dayer colder with blocking ,hope to see some of this soon creep into the models.anyway better news reagrding a colder outlook for end of nov,start of dec

[Mark Neal.]

They come on net weather and look at the model thread then decide from there

Then surely they would have come to the conclusion of winters over and its going to be another 2011 from some folk on here

Interesting times, it may not be the most inspiring look if you want cold and snow but at least it is favorable for change further down the line.

[Paul]

Can we keep it to the models in this thread please - there's a thread available for discussing the metoffice output:

[syed2878]

sorry for the off topic comment mods, if my memory serves me rite wasnt dec2010 cold spell picked up by the met by 5th-6th nov 2010.

[Liam J]

Just out of interest as I do like stormy winter weather! Some very disturbed charts as we end November looking at the raw CFS model data, and most of December looks very Atlantic dominated with a raging strong jet in top gear which would produce some notable storms. I know some of you won't like to view this but take from it what you will (if anything).... The signal then changes to that of building cold for the second half of winter towards February including March. Now I don't view the CFS everyday but, I have noticed on quite a few occasions now this general outlook is definitely the most commonly occurring one from this model (I won't use the word consistent)

CFS charts are taken from Netweather Extra.

Edited November 6, 2012 by Liam J

[Snowman.]

The quasi cool zonal mix of October looks like extending to the end of November. The 0z today is much of the same right through to the end of its run. Variance from yesterday's runs are that HP is less progressive than trough activity, vice versa yesterday.

Temps, average to cool with dry periods between the rain, that is after this relatively dry working week.

In fact, although yesterday was disappointing, today's appears to have no Scandi blocking at all and it is apparent that the westerly flow of these lows, simply push the Atlantic highs east into Siberia/Russia territory, with not even a passing shot at Scandinavia; a further step back from recent runs. So not a hint of cold on this run.

http://cdn.nwstatic....384/npsh500.png

The above is the PV at the end of FI, still flabby, but any cold progged to spill into North America and Siberia. So there remains potential for change to favour the UK, but as ever just as much chance that it will miss us, despite the good synoptics reviewed by the experts on here.

The ensembles go out to 22 Nov and show a mean in Aberdeenshire around 0c for much of FI (T850s):

http://cdn.nwstatic....erdeenshire.png

No real cold options in there at all, cool at best.

As with last year, all can change, but it does appear that we are stuck in this pattern and GFS are giving little indication of a change to colder (or milder) weather.

Hmm I can see the next 10-14 days being fairly settled but look at that chart -10 to 7 which doesn't suggest a very accurate answer now I'm not clinging onto now straws yet but the possibility of a cold flow at the end of November to December is looking likely especially if that PV decides to move again as it can't seem to settle down anywhere. I believe that this winter will be cool much like we have experienced already but with some periods of Southerly flow bringing so mild and wet conditions in the west I also believe will see record heat/rainfalls maybe even some gale force winds recorded along with some record cold/snow (not as bad as 2010 don't worry) so all in all two extremes in one winter which tbh I wouldn't mind.

[Frosty.]

Hmm I can see the next 10-14 days being fairly settled

Fairly settled?

The latest ens mean looks pretty unsettled to me with persistent low pressure close to or over the uk for much if not all of the next 2+ weeks.

[IDO]

Fairly settled?

The latest ens mean looks pretty unsettled to me with persistent low pressure close to or over the uk for much if not all of the next 2+ weeks.

"Settled" as in resolved, I think.

[Paul]

Preliminary winter thoughts from Stewart Rampling (GP):

http://forum.netweather.tv/topic/74909-preliminary-winter-thoughts/

[Frosty.]

"Settled" as in resolved, I think.

ah that explains it then as I have never seen a more unsettled outlook until well beyond mid month!

[andymusic]

yep - unsettled/windy/and cool - order of the day the next 10 - 14 days according to the latest model outputs - typical autumn fair I'd say

[bobbydog]

recently, as far as i can see (to my untrained eye) the models have been showing an on-going pattern of the PV stuck over greenland and an atlantic HP, spawning icelandic lows, giving a cold, unsettled theme with little scope for change in the near future.

now, this doesn't exactly show wintry weather for the UK, in fact it would be on the mild side. however, what it does appear to show (to me anyway) is the beginnings of a major pattern shift. looking back through the run, it appears that the russian high is the key. it slowly builds, acting as a brake on the westerly flow, throwing the jet into disarray and disrupting the PV.

i could be seeing it completely wrong but could be this the wave-breaking that GP mentioned previously?

[No Balls Like Snow Balls]

Saturday morning looks like a washout for for most of England and Wales

GFS 12z also has also thrown up a nasty little low for Wed's next week

obviously a long way off and subject to massive change but defo one to keep a eye on to see if it appear's on future runS, both GFS and other models.

[bluearmy]

day 10 GEFS develop blocking just east and north of us on 65% of the runs. expect steve m to be back shortly !! the ens are 'getting it' (or are they a bit progressive?)

[phil nw.]

day 10 GEFS develop blocking just east and north of us on 65% of the runs. expect steve m to be back shortly !! the ens are 'getting it' (or are they a bit progressive?)

Not unexpected i wouldn`t think Nick-based on the fact that NAEF`s and ECM ens mean ht. anoms. have been showing heights around that area for a few runs.

It seems the signal for this development is consistent for later in the month.

When and if it moves west remains to be seen.

[chionomaniac]

day 10 GEFS develop blocking just east and north of us on 65% of the runs. expect steve m to be back shortly !! the ens are 'getting it' (or are they a bit progressive?)

Yes, I would expect a large amplitude trough to cover the UK over the next 10 days going from the extended ECM. This will eventually wane and undercut leaving the pressure rises to the N&E. From there will we have enough wave activity feeding upwards to allow a split and pressure rises moving west?

Edited November 6, 2012 by chionomaniac