Model Output Discussion - 31/10/2014 and Beyond

[Polar Maritime]

The GFSP continues to bring the Atlantic back in around the 20th. A very wet/unsettled outlook, With a possible chilly Pm flow showing towards the end of the run.

 

Edited November 12, 2014 by Polar Maritime

[Nick F]

FWIW, I know some don't like using ENS mean charts as they are a blend of members, the 00z EPS day 10 500mb mean still shows the ridge signal up over far NW Canada/E Alaska towards the pole (though undercut by Pacific jet) and another ridge north out of N Europe toward the arctic.

 

 

UK under a cyclonic SWly mslp/500 flow by then, but the mean position of lows still not getting past the Meridain, with blocking ridge to the east. The Atlantic low influence slightly further west on ECM ENS mean compared to the GEFS mean at day 10. But, in the great scheme of things, still mild for the UK, with risk of rain at times.

 

The 06z GFS op and parallel remain ugly for coldies in the medium range, but I still think it remains unclear how much inroads the influence of the E Canadian cold upper low and subsequent re-invogorated Altantic low train will makes over the UK, given blocking just east of the UK. But deep cold, will likely remain way out of reach until December IMHO given the way current to medium range upper pattern is likely to evolve.

Edited November 12, 2014 by Nick F

[Purga]

GFS 06z is pretty grim really let's hope it doesn't verify - classic locked in mild spell.

Edited November 12, 2014 by Polar Maritime
No it's not a scorcher, So why post it. And i've removed the other wind up comment.

[Polar Maritime]

GFS 06z is pretty grim really let's hope it doesn't verify - classic locked in mild spell.

 

How is it "locked" in Purga?

Edited November 12, 2014 by Polar Maritime

[Ali1977]

The GFS ensembles are showing a big mix in FI, defo no sign of a wet SW/W set up.  It would be interesting to hear more from Snowbalz about the interesting signals later in December as she mentioned yesterday, maybe thats the period we should be looking for the first "big freeze" since March 13.

[Summer Sun]

GFS para is now on wetterzentral

 

http://www.wetterzentrale.de/topkarten/fsgfseur.html

[Frosty.]

It's no surprise to me that the models are showing nothing particularly cold, anyone who read yesterday's met office update will have noticed there is nothing cold in the pipeline, they even dropped the cold signal for the north which applied to later next week and the generally unsettled pattern continues out to the end of november and into december bar the odd touch of frost and fog patches between weather systems with temperatures close to average and milder at times. I haven't posted recently because I didn't want to get sucked into the hype that some FI charts created. I know this won't be popular, nobody on here desires cold weather more than me but until the met office hint at a pattern change then I won't build my hope up.

[SMU]

Hi Steve

I thought you said to disregard the 06z run as it was the most unreliable.

From my not very experienced view point the charts are looking like last year where the Atlantic came in late November and never left !

 

Hi yes.

 

Its hard to explain in a paragraph but the 18z & 06z are generally to be ignored, however on this occasion we can see the 00z looks heavily eastward bias so even though the 06z operational isn't pretty its made SOME correction towards the Euros because the pinch what where its going wrong ( in the baove post ) has become 6 hours closer to the reliable timeframe - hence its a little more amplified in the short term before quickly moving east in the long term.

 

imaging the GFS being the only model wrong to ALL the others at 144 ( a bit like today ) at some point because 144 is pretty near term & the 'issue' that's making it wrong is likely to be around 96-120 so even though its the poorly resolved 06z theres a chance at 96-120 it can pick up the correct pattern or at least trend towards the right one.....

S

[A.J]

GFS 06z is pretty grim really let's hope it doesn't verify - classic locked in mild spell. 

indeed, but as it's way out in the realms of FI (T264) then I would take that chart with a large pinch of salt.....in fact, I could probably drum up a higher percentage of likely verification guessing the T264 synoptics by peering into the tea leaves in my tea pot!............. whilst all postings are encouraged in this thread, cherry picking FI charts to state your case is rather disingenuous and potentially misleading to other viewers of this thread, wouldn't you agree?

[Purga]

How is it "locked" in Purga?

What I wrote PM is that I hope it doesn't verify or we could be into a nasty locked in mild spell based on the synoptics the model is showing. It won't come out exactly like it's shown on this run but the trend has been hinted at for several runs now by GFS.

Edited November 12, 2014 by Polar Maritime

[Snowy L]

I think it's becoming very clear that the outbreak of the canadian vortex lobe into East USA will just heighten the temperature gradient in the Atlantic and fire up the low pressure systems, destroying any block with ease. Not seeing any shot at cold for at least 20-25 days.

[Polar Maritime]

What I wrote PM is that I hope it doesn't verify or we could be into a nasty locked in mild spell based on the synoptics the model is showing. It won't come out exactly like it's shown on this run but the trend has been hinted at for several runs now by GFS.

 

 

Which your post still retains.. And what I wrote was, "what makes you think it would be "locked in". Let's not play with words here. Please pm any further matters on this.

 

Back to what the Models are "showing" please.

 

Many Thanks, PM.

Edited November 12, 2014 by Polar Maritime

[Bobby]

Strong agreement amongst the ensemble means on the picture at day 10, a renewed spell of cyclonic SWlies powered by an surge of low heights to our NW, and a gradual weakening of the block to our NE. Beyond day 10 it looks like this pattern further progresses/establishes. There is also a smaller probability of some more settled weather, especially for the S/SE.

 

ECM NAEFS

 

GEFS   GEM

 

NAEFS at day 12

 

 

The PV becomes tighter and more organised as we move through the month with a weakening signal for northern blocking

 

ECM day 10, NAEFS day 14

 

 

So I think it looks likely we will be heading for further unsettled weather late Nov, early Dec. A spell of disturbed zonal weather for a time perhaps. Beyond that, who knows.

Edited November 12, 2014 by Bobby

[mushymanrob]

I don't see the mild charts that some are mentioning, there's nothing 'mild' in a reliable timeframe.

 

 

 

 

really?....

its all well and good chosing a surface chart to support an agenda, but look at the uppers throughout the run (in a reliable timeframe). dont you think this will be mild? or at least average (which isnt cold), the suns out here now in similar conditions to those these uppers charts predict, and it IS mild!

its misleading to look at the expected surface pressure alone, even the short lived? easterly has high uppers, too high for much cold. the ecm looks distinctly average-slightly above average temperature wise.

 

if anyone really wants to know or get a decent idea of what weather lies ahead, then surely viewing all the data not matter if it shows a prefered weather type or not.

Edited November 12, 2014 by Paul
Removed un-needed comments (again)

[frosty ground]

 

Rtavn242.gif Rtavn722.gif

 

Rtavn1202.gif Rtavn1802.gif

 

really?....

its all well and good chosing a surface chart to support an agenda, but look at the uppers throughout the run (in a reliable timeframe). dont you think this will be mild? or at least average (which isnt cold), the suns out here now in similar conditions to those these uppers charts predict, and it IS mild!

its misleading to look at the expected surface pressure alone, even the short lived? easterly has high uppers, too high for much cold. the ecm looks distinctly average-slightly above average temperature wise.

 

if anyone really wants to know or get a decent idea of what weather lies ahead, then surely viewing all the data not matter if it shows a prefered weather type or not.

Surely the most relevant data would be 2m surface temps rather than temperature a few hundred feet in the air.........? 

Also you talk of mild or at least average....... well at least average is not mild so I am not sure why you need to expand your temperature range to prove a point that wasn't actually raised.

Either way http://www.wetterzentrale.de/pics/Rtavn12617.gif  & http://www.wetterzentrale.de/pics/Rtavn13217.gif Show temps at or around 10........ The average Max for November for England is 9.9

Your chart for tomorrow thou clearly shows mild Temperatures http://www.wetterzentrale.de/pics/Rtavn3017.gif

I agree all the Data should be shown...

 

Edited November 12, 2014 by frosty ground

[Mucka]

Just general musings from me on the output and the long term. as we may be seeing the first signs of a pattern change but not enough consistency in the models at the moment to make a proper judgement. Otherwise I will just reiterate that Friday looks like a dreadful day, especially in the West.

 

 

Obviously no cold signal in the output for the UK but still the small possibility of a more amplified pattern and cut off heights to our North which could result in an Icelandic high day 8- 10 but that is definitely the long shot at the moment.

 

 

 

I think we will see the PV try to move East past the mid term and so a slow erosion of heights over Northern/Cental Europe and Scandinavia with the possibility of some storminess for the UK developing last Week of Nov. It is possible the pattern will be more amplified and and blocking continue to our E/NE since the models are struggling a bit but we should know over the next couple of days how that will go.

 

I really don't mind either way because I see only a brief zonal period for the UK with blocking returning end nov/early Dec but this time it could well be more Atlantic based once the main core of PV West of Greenland has transferred East. (should it happen)

So I will wait and see if the Atlantic looks like pushing through around day 10 as I imagine and if it does I will then be looking for an Atlantic ridge develop behind a brief mobile, possibly stormy, period and hopefully the first proper cold signals to begin appearing early Dec.

 

If the blocking holds on and the pattern is more amplified than I imagine then great but it is still hard to see cold developing for the UK with such a powerful jet expected to develops as the Arctic air moving into Eastern US fires it up.

 

 

That said it is modelled to be on a very Southerly track an with some MLB around it is uncertain whether the Atlantic will brush aside or run over blocking as one would normally expect with a flatter jet or whether we will get some split energy and undercutting. We should have a better idea in a couple of days and plenty of weather to happen over the next few days.

[Bobby]

Surely the most relevant data would be 2m surface temps rather than temperature a few hundred feet in the air.........? 

Also you talk of mild or at least average....... well at least average is not mild so I am not sure why you need to expand your temperature range to prove a point that wasn't actually raised.

Either way http://www.wetterzentrale.de/pics/Rtavn12617.gif  & http://www.wetterzentrale.de/pics/Rtavn13217.gif Show temps at or around 10........ The average Max for November for England is 9.9

Your chart for tomorrow thou clearly shows mild Temperatures http://www.wetterzentrale.de/pics/Rtavn3017.gif

I agree all the Data should be shown...

 

 

Some more data. 2m surface temps anomaly next 10 days from GFS (posted by knocker)

 

 

NAEFS 2m temps anomaly, above/well above average from start to finish.

 

http://www.meteociel.fr/modeles/naefs_cartes.php?mode=3&code=0&ech=192&map=&runpara=

Typical chart, for Saturday

 

[Joe Levy]

The uncertainty is evident on the GFS 12z at 144hours. This is the 12z

 

and this was the 6z

The 12z has a stronger anchor of high pressure over Scandinavia and low pressure is disrupting and moving further into Eastern Europe

[mushymanrob]

Surely the most relevant data would be 2m surface temps rather than temperature a few hundred feet in the air.........? 

Also you talk of mild or at least average....... well at least average is not mild so I am not sure why you need to expand your temperature range to prove a point that wasn't actually raised.

Either way http://www.wetterzentrale.de/pics/Rtavn12617.gif  & http://www.wetterzentrale.de/pics/Rtavn13217.gif Show temps at or around 10........ The average Max for November for England is 9.9

Your chart for tomorrow thou clearly shows mild Temperatures http://www.wetterzentrale.de/pics/Rtavn3017.gif

I agree all the Data should be shown...

 

 

hi

the surface temps are directly linked to the 'uppers', although there can be occassions where theres an inversion and the milder upper air overrides the colder surface air thus trapping it in, most of the time it is not the case.

 

what i see in the current runs is mild atlantic air sweeping across the uk and into western europe. we might get this easterly, but the air originated from a mild scource, and not a cold northerly.

 

10c average? thats mild enough for me! its certainly not cold for the time of year.

 

Edited November 12, 2014 by Polar Maritime
To remove off topic content once again.

[frosty ground]

hi

the surface temps are directly linked to the 'uppers', although there can be occassions where theres an inversion and the milder upper air overrides the colder surface air thus trapping it in, most of the time it is not the case.

 

what i see in the current runs is mild atlantic air sweeping across the uk and into western europe. we might get this easterly, but the air originated from a mild scource, and not a cold northerly.

 

10c average? thats mild enough for me! its certainly not cold for the time of year.

 

A Lot of misunderstanding come about by people using feel like temperatures and Actual temperature, It may feel mild, and indeed what it feels like is probably the most important part of how someone interprets the weather around them, but for discussion about is it or is it not average then surely using actual statistics is the bes way forward.

Yes the atmosphere is all interlinked, but IMHO I think if we are discussing temperature at ground level then we should use the most relevant data, rather than extrapolated data from another series, for the examples that you give (Inversions etc).

Either way there are no cold charts to be found in the reliable......... In that you are 100% correct.

[Mucka]

Pretty clear which way GFS is heading. Yesterdays 12z runs compared to today's.

 

 

 

MetO much more reluctant to call in the Atlantic though

 

[Purga]

Frigid air over N America blasting out into the Atlantic to cause explosive cyclogenisis

 

Look at the powerful jet streak it's developing off Newfoundland

I can see that flattening any High Pressure over Europe and full blown stormy zonality taking hold.

 

So much for there not being much sign of the jet powering up !

Edited November 12, 2014 by Nick L
No need for the winding up tone

[nick sussex]

Talk about making a drama over this trough disruption. The models seem incapable of separating shortwave energy near the UK from troughing to the west and this makes a big difference.

 

Upstream the sharpness of any troughing will be effected by the amplification over the eastern USA, you can see as the amplified wave develops this initially drives troughing further south into the mid Atlantic.

 

Then the pattern flattens out and the limpet low phases with lower heights as the PV edges east, I'm not convinced this is the correct solution because the models are making such a pigs ear of deciding on the initial manner of the disrupting trough.

 

What happens for newbies to explain why the limpet low is important, as the PV edges east and its low heights phase with the low to the west the impact of this is the low shearing away to the nw, you'll note the GFS takes all the energy north over the top of the UK ridge, however if positive heights have managed to get further nw and you see where the UKMO T144hrs places the low will all the energy head north?

 

Or will it separate north and south?

 

 

 

 

[IDO]

^^^ Yes the phasing appears to create some divergence inter and cross model; though my take on things is, that despite variations in the GFS, the end result remains a flushing of lower heights from Canada into the Atlantic, towards the UK, just timing issues. UKMO at D6:

 

 

Another worrying signal from the GFS is the trend for the main PV lobe to form over Greenland/NE Canada. Today is an example, as per the op and P:

 

 

 

I do not believe that is likely to stabilise, due to the ongoing pattern of a disrupted PV, but it suggests we are in for a spell of westerly weather as it is discharged into the Atlantic. Just where the jet sits as to who gets the worse of it?

[Captain Shortwave]

The word mild has been thrown around a lot, poorly on the most part.

But this is a mild chart

Southerly sourced from north Africa with enough strength to prevent an inversion developing. If this lasted long enough then mid-high teens are possible given the source of air.

Anyway that's FI. GFS is a south westerly unsettled fest from the start of week 2. The UKMO is better but how long can that low dig into Europe before the upstream pattern over rides it.