Model Output Discussion 18z 30/09/15

[johnholmes]

It is interesting amongst all the discussion about model accuracy to look regularly at how statistically this is showing up for the northern hemisphere at 500mb. I refer to the usually daily input from Gibby, see below for this morning.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECMshow at 24 hours ECM leading UKMO at 99.6 pts to 99.5 pts with GFS closely behind at 99.4 pts.  At 3 days ECM is leading with 97.5 pts to UKMO's 97.3 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 88.6 pts toUKMO at 87.9 pts then GFS at 85.3 pts. Then at 8 Days ECM still leads at 57.1 pts over GFS's 50.4 pts. Finally at Day 10 ECM leads GFS at 36.0 pts to 29.9 pts.

 

If we look at this data then none of the models are better than about 50:50 after day 5 or so and by day 10 not much more than 1 i 3 are correct.

Something to bear in mind when posting about any of the big 3, well 2 as UK Met does not go public beyond their 120h Fax although there is a public extension out to 144h.

This leaves us with the 500mb anomaly charts as our best guide to what may happen. Everyone knows the 3 I use but there are others which are used on here. As with the synoptic models ignore single outputs and watch for continuity from day to day and between models. Even then out at day 10 and beyond great care is needed but it does provide the best guide in a 2 week slot as to what airmass is most likely to affect the UK. Beyond 2 weeks then, in the winter, some reasonable guidance is available from the MJO signal provided it has a reasonable orbit, close to the origin and it provides little help, in my view.

[Polar Maritime]

The 6z continues the theme of a more unsettled cooler Pm flow from the N/W as we head into the last week of October.

Edited October 14, 2015 by Polar Maritime

[london and south east kent]

Looks like high pressure making come back from the north east I no its long way out ....

[Nouska]

It is interesting amongst all the discussion about model accuracy to look regularly at how statistically this is showing up for the northern hemisphere at 500mb. I refer to the usually daily input from Gibby, see below for this morning.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECMshow at 24 hours ECM leading UKMO at 99.6 pts to 99.5 pts with GFS closely behind at 99.4 pts.  At 3 days ECM is leading with 97.5 pts to UKMO's 97.3 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 88.6 pts toUKMO at 87.9 pts then GFS at 85.3 pts. Then at 8 Days ECM still leads at 57.1 pts over GFS's 50.4 pts. Finally at Day 10 ECM leads GFS at 36.0 pts to 29.9 pts.

 

If we look at this data then none of the models are better than about 50:50 after day 5 or so and by day 10 not much more than 1 i 3 are correct.

Something to bear in mind when posting about any of the big 3, well 2 as UK Met does not go public beyond their 120h Fax although there is a public extension out to 144h.

This leaves us with the 500mb anomaly charts as our best guide to what may happen. Everyone knows the 3 I use but there are others which are used on here. As with the synoptic models ignore single outputs and watch for continuity from day to day and between models. Even then out at day 10 and beyond great care is needed but it does provide the best guide in a 2 week slot as to what airmass is most likely to affect the UK. Beyond 2 weeks then, in the winter, some reasonable guidance is available from the MJO signal provided it has a reasonable orbit, close to the origin and it provides little help, in my view.

 

First amplification in a long time forecast - into the Indian Ocean for late October/November - that translates to trough domination and current NWP reflecting this.

 

ECM monthly forecast   

 

 

November >1 composite.     

 

Much will depend on where it goes next - certainly outwith the behaviour seen in '97 but it will please those who are seeing shades of 2009.

 

1997     2009 

[Cheshire Freeze]

theres certainly a possibility we could get our heights retrogressing towards scandi as the lower heights try to attack from the west but id prefer zonal now than in mid nov dec.

 

Sorry to be pedantic but a HP cell can not retrogress from the west. Retrogression means to go against the prevailing flow (or backwards if you like) which, in the NH is W-E. Therefore for a high to retrogress it needs to head E-W.

Edited October 14, 2015 by CreweCold

[Methuselah]

Sorry to be pedantic but a HP cell can not retrogress from the west. Retrogression means to go against the prevailing flow (or backwards if you like) which, in the NH is W-E. Therefore for a high to retrogress it needs to head E-W.

Of course it can...Canada here I come!

[Cumulonimbus Tower]

The models seem to have come to a 'litmus test' point of autumn, in that it's been so benign and now the first signs of a change to some 'back endish' weather are appearing in the middle distance. The 06z certainly looked to be heading the way of the coldies as opposed to the 00z which looked to be flat and modern winterish . I realise that patterns shift over autumn/winter but it feels like we are about to get the first real indicator of what all the related factors (El nino, solar decline, cold Atlantic etc) will deliver when added together in the real world; flat muck or meridional mix  

[Mucka]

It is interesting amongst all the discussion about model accuracy to look regularly at how statistically this is showing up for the northern hemisphere at 500mb. I refer to the usually daily input from Gibby, see below for this morning.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECMshow at 24 hours ECM leading UKMO at 99.6 pts to 99.5 pts with GFS closely behind at 99.4 pts.  At 3 days ECM is leading with 97.5 pts to UKMO's 97.3 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 88.6 pts toUKMO at 87.9 pts then GFS at 85.3 pts. Then at 8 Days ECM still leads at 57.1 pts over GFS's 50.4 pts. Finally at Day 10 ECM leads GFS at 36.0 pts to 29.9 pts.

 

If we look at this data then none of the models are better than about 50:50 after day 5 or so and by day 10 not much more than 1 i 3 are correct.

Something to bear in mind when posting about any of the big 3, well 2 as UK Met does not go public beyond their 120h Fax although there is a public extension out to 144h.

This leaves us with the 500mb anomaly charts as our best guide to what may happen. Everyone knows the 3 I use but there are others which are used on here. As with the synoptic models ignore single outputs and watch for continuity from day to day and between models. Even then out at day 10 and beyond great care is needed but it does provide the best guide in a 2 week slot as to what airmass is most likely to affect the UK. Beyond 2 weeks then, in the winter, some reasonable guidance is available from the MJO signal provided it has a reasonable orbit, close to the origin and it provides little help, in my view.

 

I think we have a similar discussion every year, but here goes. 

I upvoted the comment because essentially I agree it is always good to be reminded that the models lose accuracy pretty quickly beyond day 5 and we should never take one run in isolation and use that as a guide, especially if it goes against the anomaly forecasts etc.

Also excellent guide to the available tools for different time-frames.

"But"

By the same token we should not use anomaly charts etc in isolation and dismiss operational runs that show something different, especially if there is any support from control runs or other models at all because no one tool is perfectly accurate and an hi res operational run will pick up on a potential pattern change that anomaly forecasts will not. It doesn't happen that often but when it does we simply see the ensemble and anomaly charts "flip".

So really it depends on whether we wish to speculate on potential changes or make probability forecasts and personally I think there is more than room enough for all approaches and it is what makes the MO thread in winter so entertaining (and exasperating for some I'm sure  )

 

 

This morning's ecm anomalies shows the transition to a more unsettled westerly regime, in line with the GEFS, as the mid Atlantic trough exerts itself and the ridging slides east.  This continues into the ext period with the trough the dominant player as the ridge is situated east of the Baltic. A number of posters have suggested that there is no great evidence of change, putting aside blown away by the jet for the moment, so I've reluctantly concluded that I'm hallucinating.

 

You are not hallucinating Knocker 

I think the discussion is more about the scope of the change and with it being quite far out people are entitled to say high pressure will be in charge for the foreseeable.

That high will come under pressure from a trough digging down from the NW as we get toward last week of October but this has been on the cards and discussed for some time. The real question is how far south will the trough get and what will we get upstream? Is this a full breakdown into typical zonal fare or will the pattern quickly reamplify?

So far my thoughts have been that there is no evidence that this transition into a more unsettled regime is the start of an Atlantic onslaught and currently I think that is still the case but the models have not yet picked up any particular pattern zonal or blocked for FI so it is pure speculation.

The anomaly charts don't really help us here (at the moment that is - though they should as the models settle down and favour a particular synoptic) because they are simply showing the transitional period of declining high pressure over the UK - that does not mean we are going zonal, it just means that the overall signal has a trough affecting the UK around the 8-11 day range.

 

Currently the models are playing around with dropping a trough into Scandi which may well allow heights to rebuild in the Atlantic a little further down the line although that is where the other longer range tools John mentions come into use.

Conversely we have seen them try to build a Scandi high and bring an Atlantic trough and there is a faint + height anomaly over Scandinavia in your chart.

This is the biggest issue with anomaly charts because they are not that useful for forecasting "What happens next" when the models are in a state of flux as any signal is muted. It is better to manually check through the model output and ensembles and look for plausible patterns as a clue and remember that the anomaly charts are built on that output.

 

That is why I say there is room for all approaches, so long as they are based on MO, and it makes for some good discussion on what we may be facing in FI.

They all have their strengths and weaknesses and then we have some very informed and articulate members who can bring all the massive array of information together and try to make sense of it instead of waffling on like I just have, sorry. 

 

So yeah we may face a more unsettled spell as we head toward/into last week of October but I don't think we have a good signal as to what comes next as yet and this is where the speculation, alternative views are all good discussion.

Don't hang your hat on a typical zonal pattern setting up just yet Knocker. 

Edited October 14, 2015 by Mucka

[Summer Sun]

Looking at UKMO this high could be with us for a good while yet cloud amounts are always going to be difficult to predict but where its clear overnight frosts are likely though still pleasant by late morning where its sunny after cold starts

 

[nick sussex]

The GFS tries to bring a little colder interest towards day 8 with the low dropping into Scandi but still too flat upstream and the core of any cold heads south further east.

 

Still some reluctance to bring an end to high pressure within the T240hrs timeframe. We'll wait and see what the ECM does soon.

[knocker]

The GEFS anomalies still looking at a nice quiet period before the breakdown of the HP cell to a more westerly regime with the trough in the Iceland area bringing more unsettled weather but mainly in the north with the south remaining not too bad.

http://www.tropicaltidbits.com/

 

[knocker]

Nice contrast. Daffodil picking in Cornwall and speed skating in Lerwick

 

[Singularity]

The run-to-run consistency has tanked over the past couple of days. Flicking from GFS 00z to 06z to 12z det. runs does not inspire much confidence in the evolution beyond +120 or so.

 

Interesting to see that the MJO amplified majorly in the same phases in 2009 as is expected this year. I say that not so much because of the winter that followed but because in 2009 the Atlantic storms kept on coming up against blocking highs well east of the UK. A couple of examples:

 

 

...and this led to a very wet outcome for parts of the UK, with my own observed total ranking the highest in all months going back to 2000 at an astonishing
242 mm for the month.

 

It also betrayed the blocked tendency of the patterns leading up to that winter. The point for the near-term though is that as much as the MJO composites signal for a trough to dominate, it also allows for blocking to our east and northeast to hold up the storms and bring slow moving frontal rain plus a lot of showers in the return polar maritime winds - especially across the southwest and south. They were a major contributor to the extreme totals I experienced that month - I can recall thunder on several occasions.

 

So this is essentially a heads up that after two months of predominantly dry weather with only brief interruptions, November could be about to swing the pendulum very far the other way...

 

But I must emphasise the 'could' in that statement 

[bluearmy]

The GEFS anomalies still looking at a nice quiet period before the breakdown of the HP cell to a more westerly regime with the trough in the Iceland area bringing more unsettled weather but mainly in the north with the south remaining not too bad.

http://www.tropicaltidbits.com/

That's the gefs picking up the Scandi block holding back the Atlantic aswell then knocks. Like I said last night, how far across us any breakdown gets is the question I would be asking. The last break had some systems coming from way to our South west which gave quite a deluge before the block pushed back. This time, it seems the push comes from the developing vortex over eastern Canada. unlikely to be so moist and could easily swing ne or slide se against the blocking to our East.

EDIT: the 12z ECM eps bring the troughing further east than previous runs and takes the UK completely under the the Atlantic influence with the blocking more scrussian than sceuro.

Edited October 14, 2015 by bluearmy

[knocker]

That's the gefs picking up the Scandi block holding back the Atlantic aswell then knocks. Like I said last night, how far across us any breakdown gets is the question I would be asking. The last break had some systems coming from way to our South west which gave quite a deluge before the block pushed back. This time, it seems the push comes from the developing vortex over eastern Canada. unlikely to be so moist and could easily swing ne or slide se against the blocking to our East.

EDIT: the 12z ECM eps bring the troughing further east than previous runs and takes the UK completely under the the Atlantic influence with the blocking more scrussian than sceuro.

 

Just beat me to it Blue. I was just going to go into my 'in the blue corner................and the daffodil corner routine with odds of 4/6 and 5/4 the field. This chart prior to the trough shifting SE

 

"Abandon hope all ye who enter here"

Edited October 14, 2015 by knocker

[Ali1977]

Strange looking GFS in FI - I have a feeling something quite unusual may happen early Nov....Pressure seems to want to build in Northern Canada and Greenland later Oct according to last few runs.

[Met4Cast]

That's one majorly disrupted polar vortex in FI on tonights 18z

 

[Polar Maritime]

The GFS this morning continues to show an unsettled/cool possible stormy end to October, As a deep Low swings in from the N/W turning Northerly as the Low passes. It's nice to see something more mobile showing as we head into the last Month of Autumn.

Edited October 15, 2015 by Polar Maritime

[knocker]

The GEFS anomalies this morning at T144 have the HP slipping slightly SW with a low pressure Canda/Greenland and associated trough orientated to the north of the UK. This is enough to concentrate the jet and wing depressions north as can be seen by consulting the ops. Further to this by T240 it further denigrates the HP and makes the trough more influential thus tracking the depressions further south. The 11-15 period which must be subject to some uncertainty has the upper trough around Iceland with a flat zonal flow which would herald unsettled weather for the northern half of Britain but not too bad in the south.

http://www.tropicaltidbits.com/

Edited October 15, 2015 by knocker

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON THURSDAY OCT 15TH 2015

 

THE CURRENT GENERAL SITUATION  A High pressure ridge remains extended across Scotland from the East with a cold NE flow across the South of Britain with troughs remaining close to SE England.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif

 

CURRENT SNOW LYING UK AND NORTHERN HEMISPHERE There is currently no snow lying in the UK with the freezing level ranging from just around 8000ft across Scotland and Ireland while nearer to just under 5000ft across much of England and Wales. The snow cover above 60 deg North continues to expand across mainland Russia and the States which extends to 55 deg North in western Russia.

 

http://www.snow-forecast.com/maps/dynamic/uk

 

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

 

MODELS-2 WEEK HEADLINE  Remaining mostly fine and settled with frost and fog patches at night and only relatively small chances of significant rain more especially in the North and West later.

THE GFS JET STREAM FORECAST  The GFS Jet Stream Forecast shows the flow currently a long way to the NW of the UK where it remains for some while yet before strengthening early next week and beginning to sink further South across the UK later as Low pressure from the North of the UK slips further South.

 

http://www.netweather.tv/index.cgi?action=jetstream

 

GFS OPERATIONAL The GFS Operational Run today shows High pressure to the Northeast with a cool NE flow across the SE. This flow is cut off over the weekend as the High pressure zone slips further South across Britain and away to the South. This opens the door to milder Atlantic Westerly winds and an increasing risk of rain at times. Then through the second week cyclonic and often cold weather prevails with spells of wind, rain and showers and cold enough for snow at times over Northern high ground.

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif

 

THE GFS CONTROL The theme of the GFS Control Run is similar to the operational for the first week but through the second week a pronounced cold Northerly affects the UK for a day or two with rain followed by showers, wintry in the North. then pressure quickkly rises and a frosty cold but dry period looks likely for a time before milder SW winds strengthen and bring rain back rain into the North and West towards the end of the second week.

 

http://www.meteociel.fr/modeles/gefs_cartes.php

 

THE GFS CLUSTERS(14 Days) The GFS Clusters in 14 days seems to have unanimously shifted their output towards a unsettled period of weather by 14 days with Low pressure to the NW affecting the UK with rain at times in milder SW winds. There are varying degrees of extent of this unsettled weather with 5% of members going for a major storm system up to the NW at Day 14 with severe gales and heavy rain in places.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows the belt of High pressure across the North slipping South and removing the cold NE flow across the South over the weekend but increasing a milder Westerly flow across the North. Many areas will remain quite dry with the influence of mist, fog and frost by night transferring to the South by the start of next week

 

http://www.wetterzentrale.de/pics/Rukm1441.gif

 

THE FAX CHARTS The Fax Charts this morning show High pressure remaining in control over the UK with the weak fronts affecting the SE decaying and moving away along with the cool NE flow by the beginning of next week.

 

http://www.weathercharts.org/ukmomslp.htm#t120

 

GEM GEM today reflects High pressure remaining in control across the UK for the next 10 days but with some fundamental differences developing. The cool NE flow across the South will dissipate after this weekend as the High pressure belt shifts to Southern Britain while the North and most places in general see rather milder conditions take hold by day, only by day in the South but by night too in the North, all due to Westerly winds and rain bearing fronts affecting the North later. 

 

http://www.wetterzentrale.de/pics/Rgem2401.gif

 

NAVGEM NAVGEM also shows High pressure remaining under control across the UK throughout its 8 day period with the centre shifting towards a point close to Southern England early next week but re-establishing nationwide again by next weekend. Largely fine and dry weather looks likely with variable and often large amounts of cloud, a little rain in the North for a time next week and then areas of mist, fog and frost possible in rather cool conditions later in the period.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif

 

ECM ECM this morning also shows High pressure changing it's position over the coming 5 days or so shifting the emphasis of the best weather away from Scotland to Southern Britain and importantly removing the persistent NE flow of late away from the SE. Milder and cloudier Westerly winds look like developing over Scotland with a little rain which does show some signs of sprading to other areas too late next week before a cold Northerly flow looks the precursor to renewed and cold High pressure moving back in again from the West soon after the term of the run.

 

http://www.wetterzentrale.de/pics/Recm2401.gif

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows High pressure declining away to the East with some troughing developing across the UK in winds from a Westerly source.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The main trend from this morning's output continues to support somewhat milder conditions to develop later next week as High pressure slips to the South of the UK later.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM leading UKMO at 99.6 pts to 99.5 pts with GFS closely behind at 99.4 pts.  At 3 days ECM is leading with 97.4 pts to UKMO's 97.2 pts while GFS lags behind at 96.3 pts. At 5 days ECM leads with 88.6 pts to UKMO at 87.8 pts then GFS at 85.5 pts. Then at 8 Days ECM still leads at 57.3 pts over GFS's 50.2 pts. Finally at Day 10 ECM leads GFS at 36.2 pts to 30.8 pts.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

 

MY THOUGHTS   Today's output continues to support signs of change this morning though as I hinted at yesterday it may not be for long and not mean much in the way of rain for some. What we have seen of late is a stalled situation of High pressure to the North and NE of the UK extending a ridge back West over Northern Britain who have seen days now of splendid Autumn weather if with some cold and frosty nights. In the South and SE things have been a little more marginal with cloud and even a few showers at times in a persistent and cool NE wind. Fortunes will switch round next week with the South seeing the best of what should be plenty more fine and settled weather with milder days but still with the risk of mist and fog and a touch of frost at night. The North on the other hand will become breezy and milder generally with a lot of cloud and some occasional rain as fronts increasingly make progress across these areas. Then as we look further out GFS seems to want to set up a more mobile pattern with a couple of cold Northerly incursions, something that is also supported by ECM late in it's run this morning. My feelings are that although I think milder, windier and changeable weather is almost guaranteed to reach the North next week as the Jet Stream strengthens and moves South other areas of England and Wales probably won't see much in the way of rain before pressure rebuilds from the Atlantic later, possibly right across all of the UK with cold and frosty weather returning for many. This is the way I see it but it maybe of course that the Jet Stream's predicted extra strength will keep a much more mobile and possibly milder scenario across the UK such as the GFS Clusters are biased towards today in association with a possible intense Low pressure up to the NW. We will see how things develop over the coming days.

 

WORST CHART OF THE DAY 00z RUN

 

http://www.wetterzentrale.de/pics/Rtavn2761.gif

 

For the worse chart of the day I have chosen GFS at 276hrs which illustrates our current High pressure long gone with Low pressure across the UK with wind, rain and quite chilly weather across all of the UK.

 

BEST CHART OF THE DAY 00z RUN

 

http://www.wetterzentrale.de/pics/Rtavn1081.gif

 

The best chart today goes to GFS too but at 114hrs out which shows the current High pressure belt well in control across the UK with what should be almost universal fine and dry weather with some mist, fog and frost chances by night but bright, fine and potentially sunny days.

 

Next update from 09:00 Friday Oct 16th 2015

[knocker]

Although the timing isn't the same the ECM also brings a trough to the north of the UK in the 6-7 day range with LP systems winging their way past to the north. This becomes a more general trough mid Atlantic by D10 bringing unsettled weather certainly to the north.

 

 

[phil nw.]

Although the timing isn't the same the ECM also brings a trough to the north of the UK in the 6-7 day range with LP systems winging their way past to the north. This becomes a more general trough mid Atlantic by D10 bringing unsettled weather certainly to the north.

Yes the trend to the north of lower pressure continues and seems to have an air of inevitablity about Knocker,however...

There are still differences in emphasis on any breakdown of our mid-latitude blocking by day 10.

 

Comparing naef's and ecm ht anomalies.

 

the American outputs seem keener or maybe quicker on developing any Atlantic trough- which they go onto deepen by the end of week 2.

Some change looks likely next week now though but whether that is just a breakdown further north or more widespread is unclear to me at this stage.Any change looks slow and the upstream jet certainly not yet in full gear.

[johnholmes]

Just mulling over comments in the thread, and good to see constructive comments from folk with differing views.

 

I never or very rarely post regarding the anomaly charts without having looked at the synoptic models and over the winter the MJO, also at times reading the technical bits from NOAA about how the models seem to be predicting the long wave pattern for the northern hemisphere. Without doing this then one is liable to get a rather blinkered view of the output. This maybe why, in winter with so much hope going on to snow and frost conditions, we see posts that are based solely on one model and one run then hypothesising on what might happen if one thing or another happens. Next thing we know the model thread descends into minor chaos for a short time, not unlike what the synoptic models are apt to do now and then over a 24 or 48 hour period before settling back down. Nothing wrong with this approach but do be aware it is less likely to be a balanced view than a more widespread, careful assessment, at all model outputs. Let’s just hope and all try this winter period to keep our posts respectful to one another and allow anyone posting charts to their viewpoint.

End of jh plea!

 

back to the outlook, say 5 days onwards.

Not much change in the overall upper pattern close by the UK at first but slowly the more changeable/unsettled idea of the Atlantic beginning to affect more parts of the country looks like happening. The anomaly charts and the MJO (GFS) suggest this into early November, or do so according to my interpretatopn of their outputs, see links below

http://www.americanwx.com/raleighwx/MJO/MJO.html

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

I would agree with phil above re no major Atlantic wind up on offer so far.

Edited October 15, 2015 by johnholmes

[knocker]

Yes the trend to the north of lower pressure continues and seems to have an air of inevitablity about Knocker,however...

There are still differences in emphasis on any breakdown of our mid-latitude blocking by day 10.

 

Comparing naef's and ecm ht anomalies.

naefsnh-0-0-240.pngEDH101-240.GIF.png

 

the American outputs seem keener or maybe quicker on developing any Atlantic trough- which they go onto deepen by the end of week 2.

Some change looks likely next week now though but whether that is just a breakdown further north or more widespread is unclear to me at this stage.Any change looks slow and the upstream jet certainly not yet in full gear.

 

Yes I would agree the Jet isn't in full gear but differ vis the American outputs. The ext ecm this morning is tending towards a trough orientated Atlantic with no apparent sign of HP build up.

[phil nw.]

Yes I would agree the Jet isn't in full gear but differ vis the American outputs. The ext ecm this morning is tending towards a trough orientated Atlantic with no apparent sign of HP build up.

The trough development wouldn't be a surprise Knocker,it's certainly reflects analogues from previous strong nino years that i and others have posted recently.The re- build of Scandinavia heights later would also fit as we go into November.

 

 

It will just be interesting to see if we evolve into something like that.

Edit

I should add my analogue chart only uses years that also saw a west based QBO.

Edited October 15, 2015 by phil nw.