Model Output Discussion 1200 hrs 15/11/14

[Tamara]

Rinsing and re-cycling into winter as the NH pattern backs west

 

Late autumn into early winter weather NH patterns continue to evolve on cue through feedbacks

as suggested and outlined in October/mid autumn in postings on the OPI thread

 

The first half of November has seen a significant Aleutian Low, disrupting atlantic trough and Scrussian High very well advertised, and this is the ongoing seasonal pattern set to keep rinsing and re-cycling into the winter.

 

The rinsing and recycling process is already insidiously backing the pattern west and this in turn will stimulate further (and stronger) wave breaking mechanisms into the pole. These wave breaks, being directly reactive in themselves to the prevalent NH pattern, feedback over and over again to sustain a predominant -AO signature over the pole.

 

This predominant -AO signature of course waxes and wanes, as the cycle rinses and repeats, but through the feedback process, attains greater and greater significance for larger areas of NH mid latitudes with time - and of course this includes Europe and the UK and not just the US and Canada who look set to enjoy a further round of spoils in the shorter term.

 

Our current synoptic charts should be viewed as the end of the first stage (of quite conceivably a few) of this process - and although we have no cold air (as expected) to advect from the nearby continent, we have the High to our NE in ascendancy of our weather for the coming days - as the troughing to our west and south west recedes - for a time.

 

After incessant cyclonic SW'erlies in our parish (being very close to the trough disruption graveyard to our W/SW),we at last see a continental drift, which, on its own, is delivering very ordinary quiet(er) autumnal weather ( but gives a lovely respite to seemingly interminable sogginess!!) and which represents a theme that should attain greater and greater bite to it with time as the Eurasian feedback pulls an ever growing and deepening cold pool further and further westwards at the completion of each cycle

 

Stratospheric activity in tandem with the feedback should be expected to become increasingly more ruthless and relentless, as I see it, on the vortex  . However, cautioningly at our tropospheric level, we should think of the westward pattern adjustment process as something sequential, and not entirely continuous.

 

To highlight such pauses, the upcoming end of month and start of December highlights some gathering of vortex energy to our NW as was suggested in the last MOD update (and is entirely consistent with stratospheric developments). This is now well signposted in 10 day-ish NWP output for the final days of November. This, again, completely in line with tropospheric expectations.

 

On this basis, with too much energy transport to our NW, we should not expect our higher pressure interlude to lead to any fast-track to real cold. What it should do however is provide more seasonal weather off a cooling continent, lower dewpoints, and assist with dispelling the unwelcome presence of excess and overstayed autumn warmth - which is plaguing our surrounding seas, and further exacerbating rainfall so much as we have seen recently. Especially on coastal areas exposed to prevailing winds.

 

Beyond some interim surface benefits, what is significant though about this completion of phase one pattern backing, is that as a measure of progress we are unlikely to see the next tranch of unsettled conditions be as extensive eastwards as we have seen during the first half of November. This despite the US likely heading back into the freezer again, and temperature gradients steepening as that vortex energy gathers over Canada and Greenland.

 

The theme of trough disruption, as well advertised by the models in the next burst of cyclonic energy, is of course highly encouraging to keep seeing and is part of the background template pattern which, eventually, should translate to coupling the anticipated -AO winter pattern better with the NAO. Achieiving a fully fledged -NAO remains, and is set to remain, elusive for a while longer despite model teases that seem to keep help turning a few MOD thread pages

 

The hostile place, that the mid and upper vortex is set to continue living in, might not be helping us this early, but the background feedback pattern is frankly unstoppable in its direction as I see it, and it is this that I know I put own trust in - and use as a base for logic and associated present and future continuity of reasoning.

 

We cannot ever guarantee freezes on this little crossroads- of- airstreams Island we occupy (as a fraction of the NH). But fully expect continued resistance from the east and north east, and fully expect resistance from the east and north east to become an ever much tougher 'foe' (friend  ) as we head deeper and deeper into winter.

 

I would like to add a welcome to the return appearance of Old Met Man for the season - always much appreciated by many of us at this time of year

Edited November 18, 2014 by Tamara תָּמָר

[fergieweather]

Uncertain what the next batch of charts will indicate, but the latest forecast for next week just issued by METO indicates slightly below average temperatures with increasing risk frost in the east and risk of some rain in the west. Read what you may into that, but seems blocking to the east could still hold up the Atlantic advance for a while longer anyway.

 C

 

It *could*, but the west-v-east situation still unresolved (ahead of 12z output, at least) and clearly finely balanced, albeit a trend to slow mobility is their favoured outcome (the high level of uncertainty needs stressing). Whether the 12z suites offer more compelling evidence either way, we shall see.

Edited November 18, 2014 by fergieweather

[carinthian]

It *could*, but the west-v-east situation still unresolved (ahead of 12z output, at least) and clearly finely balanced, albeit a trend to slow mobility is their favoured outcome (the high level of uncertainty needs stressing). Whether the 12z suites offer more compelling evidence either way, we shall see.

Thanks for that information Ian. Probably wise not to look much beyond 144hours. Anyway makes for good viewing and always the possibility of the surprise elements.

C

[gottolovethisweather]

It *could*, but the west-v-east situation still unresolved (ahead of 12z output, at least) and clearly finely balanced, albeit a trend to slow mobility is their favoured outcome (the high level of uncertainty needs stressing). Whether the 12z suites offer more compelling evidence either way, we shall see.

 

Thank you and if you could kindly arrange it so that the inevitable Atlantic mobile pattern gets pushed back further by another day and another day over the following outputs, I suspect it would be most welcomed by many in here.   At this rate, it may well be Winter (meteorologically speaking) before the breakdown arrives, if at all.   Now for the reality check.

 

A few of us (myself included on occasion) could be getting ahead of ourselves with our excitement for cold solutions, but there is certainly plenty of scope for it to ocur in deep FI, I believe, so all is not lost. A milder end to the week and overall a drier picture for now is where its at within the reliable, at least IMBY.

 

On with the 12z outputs we go. 

Edited November 18, 2014 by gottolovethisweather

[Swave Snow]

It *could*, but the west-v-east situation still unresolved (ahead of 12z output, at least) and clearly finely balanced, albeit a trend to slow mobility is their favoured outcome (the high level of uncertainty needs stressing). Whether the 12z suites offer more compelling evidence either way, we shall see.

 

 

Early on and on the GFS 12z everything is that tiny bit more eastwards, so slow mobility at this point looks like happening need to wait a little longer to review all the models as they come out for the 12z

 

But could there be an undercut on this one?? (GFS 12Z?) = not likely 

Edited November 18, 2014 by Swave Snow

[shaky]

Difference already at 90 hours! ! 06z had low pressure centre West iceland whereas 12z has it way south west of iceland! ! Gfs parallel has high further west up to 60 hours

[legritter]

I would also like to echo other posters thoughts on any possible pattern change ,looking at all current charts Mild with typical late autumn weather for now .Then a possible battle between high pressure over central and some parts of northern europe probably taking place in about 5/6 days .over the last weeks there has been some very interesting charts on offer and also a lot of variation from day to day ,I would not be surprised to see some Tasty charts appearing tonight and over the coming few days ,I have always said we have a Great forum here on Net weather and its great when we get input from professionals and experienced posters .  STellas all round 

[swfc]

Interesting the waa going into greeland at 138hrs and slightly higher pressure.may be nothing but there none the less

[nick sussex]

Unbelievable!

 

FI starts at T96hrs, UKMO at T96hrs:

 

 

GFS at T96hrs:

 

 

This makes such a difference as to how far ne that high to the sw might ridge later ahead of the upstream troughing, the GFS has moved towards the ECM 00hrs but the UKMO refuses to back down.

 

The GFS has now a deeper low over the USA which will interact with the PV, for newbies if you're interested in why this is important I posted on this earlier, post 474. It might still be close but no cigar with this GFS run but its still a step in the right direction.

Edited November 18, 2014 by nick sussex

[johnholmes]

It has always been an issue with trying to forecast with the Atlantic trying to break down a surface high and upper ridge to our east or NE. Neither human trying to do a forecast for 24-72 hours ahead nor any model at time scales beyond 48-72 have yet overcome this issue. Why we cannot remains a mystery, as both work on basic physics. Cold air is dense and usually associated with the surface high and is almost always hard to shift.One day maybe the models will be able to give a better feeling for what is likely. Refer to the 500mb charts for what pattern any of the models are suggesting, ignore the surface until they show similarities. That is assuming the 500mb charts are showing consistency with time and one another.

Edited November 18, 2014 by johnholmes

[swfc]

Looks like tamaras post earlier maybe not far off the mark here.Amazing isnt it you get the low slipping south but the heights to the north andeast have moved away.oh well roll on ecm i guess

[IDO]

Looks like tamaras post earlier maybe not far off the mark here.Amazing isnt it you get the low slipping south but the heights to the north andeast have moved away.oh well roll on ecm i guess

Yes consistent output now. Even with changes in short wave variables, timings and positionings of ridges and troughs, the long wave pattern remains predictably stable. At D10 the stand off remains between the block and Atlantic. The main area of uncertainty is the boundaries and surface conditions due to the messy nature of the UK being caught in no mans land between these competing forces. GFS op and Parallel along with GEM all very similar in the over all Synoptics. At D10 we have a strong pulse of lower heights descending on the UK from the NW and FI maybe from here, as to how the models deal with that:

 

D10:   

 

Though I don't see a short cut to anything cold from here.

Edited November 18, 2014 by i'm dreaming of...

[knocker]

The GEFS anomaly has been pushing the upper trough slowly east the last few runs.

 

Any energy left after this though

 

Upper level pattern highly amplified ... opens up Trans-Siberia polar express to Midwest pic.twitter.com/JzENsW3aEZ

[mushymanrob]

The Easterlies that COULD appearer on the 12z........ I think the poster is making the point that the 384 hours chart changes all the time.

 

d'oh...i knew i wasnt reading it right... cheers for that.

[gottolovethisweather]

Looking at the GFS(P) 12z NH Jetstream profiles alone. On my posting here back on the 13th November, it was suggested that by 0300hrs this Thursday it could like this.

 

 

The reality now by the same timeframe (now at t+39) is as shown below.

 

 

 

The biggest change in its evolution is the area encircled in red which just so happens to be over the UK itself. Clearly one to watch as the Jet is having a tendency to move further South by this early timeframe in response to a strengthening European block. 

 

I've added the next NH Jetstream image for the end of the week, as at t+75 hours to indicate it's relaxed state, at this stage. Besides this, there will be slightly above average surface Temperatures towards the far SE of the UK by then. 

 

 

 

Heading deeper into the comparitive timeframes of last Thursday's post and what the NH Jet was forecast to show by 0300hrs on Sunday 23rd November. 

 

 

The reality as shown by today's 12z is far removed from the forecast position hinted at, some five days ago. 

 

 

The area encircled in red once again, this time showing Western Europe and best part of the UK still largely under the influence of the European block and not the Atlantic. The warmest, albeit slightly above average Maximum Temperatures now promoted off into the continent. Another watch area (also encircled in red) as per five days ago is the North Pacific region as by then, there is potential for a more rampant Jet in this region by this time.

 

Finally, where were we forecast to be by midnight next Wednesday.

 

 

Now, we are expected to see the following, with regard to NH Jetstream profiling. Of course, it's deep FI even by this stage and as is usual the GFS (P) is returning to its almost default pattern of a seemingly rampant Jet. Personally, I will believe it when I see it and hopefully we won't. Draw your eyes towards the UK in relation to the bigger picture over the North Atlantic and Pacific region now and what do we have, NO MAN'S LAND. 

 

 

Finally, just for the heck of it, how about a NH Jetstream profile for the 1st December. 

 

 

And then its associated T850s, well really, is there really any point?

 

and hello December      

 

 

 

Overall summary

 

• The GFS (P) promotes FI Atlantic influence once again in its far reaches but in the meanwhile, a largely dry picture, hopefully with some sunshine around by day along with perhaps a little frost on the clearer nights. Temps largely around average for most but colder when any mist or fog lingers. The NH Jestream analysis provides but only one part of the bigger picture to illustrate how nature's forces will influence our little patch in the globe. However, I hope it assists a few newbies or lurkers as to what we do or don't want to see, if we are to avoid another Atlantic based climatological setup, akin to Winter 2013/14.   Very early days yet but as a coldie, I live in hope of something more seasonal around the corner. 

Cheers

 

gottolovethisweather

Edited November 18, 2014 by gottolovethisweather

[carinthian]

You have heard from Ian and the experience of John Holmes. A high level of uncertainty in this type of set up (ie) West v East. Beyond 144 hours forecast models low confidence. Interesting forecast period to evolve.

C

[bluearmy]

And yet, amidst all the uncertainty, we have the higher res ops at day 9/10 (ec/gem/gfsp)  all taking a depression se without there being obvious resistance to it heading ne. as i said yesterday, it wouldnt surprise me if this depression ends up a bit further west by the time it tends se into europe. it could be an interesting european visitor. watch this space.

[MR EXTREMES]

but the overall trend is a rinse and repeat as tamaras post suggested and although we are in a stalemate there really is not alot to be excited about and am finding it difficult to work out how and where the cold train comes from.

 

its not east and it would have to be something super extreme from the west maybe a nw but that will only be any good to the nw we have no greenland block and a polar vortex where we dont want it and its all rather messy if you ask me and possible states get the best of it again with record cold.

 

and we get the soggy wet windy.

the gem upgrade throws out this 

ukmo is heading towards a flat zonal and complete flattening of the heights to our east.

gfs to wants to play the zonal game really nothing to be excited about and the concern is that last year this lasted all winter.

couple that with every long range weather model going for average to above average then i really dont see the excitement,

[chionomaniac]

And yet, amidst all the uncertainty, we have the higher res ops at day 9/10 (ec/gem/gfsp)  all taking a depression se without there being obvious resistance to it heading ne. as i said yesterday, it wouldnt surprise me if this depression ends up a bit further west by the time it tends se into europe. it could be an interesting european visitor. watch this space.

Agreed here. I wouldn't be surprised to see the whole pattern back further and further west as we enter and progress throughout Dec....Bit by bit

[swfc]

Agreed here. I wouldn't be surprised to see the whole pattern back further and further west as we enter and progress throughout Dec....Bit by bit

Could i ask you why?Thanks in advance

[Polar Maritime]

As i mentioned this morning, It does look like the Low may drop S/E drawing a cool Pm N/Wly and possibly cut-off over the UK giving us a better chance of a colder feed from the East N/E. But with such high uncertainty 'which usually marks the sign of a pattern change' We have some very interesting Model watching coming up over the next few days. Better already than of all last Winter alone. 

 

Edited November 18, 2014 by Polar Maritime

[bluearmy]

I think a slow read of tamara's post by everyone would go a long way to making interactions on this forum more amenable.  one of the best pieces i've seen on this thread in many a year.

 

given the inter model agreement, what odds that ecm 12z loses the diving trough !!

[Polar Maritime]

I've just had to delete some post's, Please keep on topic and be polite 

 

Thanks, PM

[Banbury]

As i mentioned this morning, It does look like the Low may drop S/E drawing a cool Pm N/Wly and possibly cut-off over the UK giving us a better chance of a colder feed from the East N/E. But with such high uncertainty 'which usually marks the sign of a pattern change' We have some very interesting Model watching coming up over the next few days. Better already than of all last Winter alone. 

 

You have hit the nail on the head

 

It is much better than last year and we are only mid November

[LomondSnowstorm]

I can't say I have much confidence or even a desire for a 'zonal reset' some talk about on here - we saw exactly the same last week with the models, particularly the GFS/GEFS, trying to blow the high away, and yet still the troughs are unable to get east of the meridian and the block over Scandinavia remains.

Here's what we should've had by the end of this week:

and yet this is what we're actually looking at for Friday:

 

Now, I'm certainly not saying it's inevitable that we'll see further westward corrections but from the current modelling at +192 (which incidentally doesn't blow up the PV over Greenland anything like as much as Thursday's 12Z did for +192) it certainly wouldn't take a massive shift to keep us at the very least in a continued stalemate or UK high type setup and potentially even something a bit more interesting if we do finally manage some troughing going under into Europe:

 

Even if we do see a more mobile pattern (and I think we are likely to see at least hemispherically a more +ve AO pattern for early December even if we do end up keeping some blocking in situ) then, as Tamara said, the November pattern, both tropospherically and stratospherically, is panning out broadly as the OPI/SAI/QBO analogues would predict, which is definitely good news for those of us looking for a shot at some decent cold spells during winter itself.