Model Output Discussion - 7th-13th November

[nick sussex]

Thanks for that Nick, some lovely images there. Unfortunately the way things are shaping up (or perhaps more accurately refusing to change) on the models, webcam viewing of snow is the best most of us can hope for through this month at least...

Thanks yes at least I can look out of my window at the mountain snow! I can't see any valley snow here for the foreseeable future. No matter how much we might want the pattern to change theres no major sign of this.

It's really slight variations on the same theme, things will eventually happen upstream but we're just going to have to be patient.

You could look at several timeframes in todays ECM run and could see a small window of opportunity where with a few small changes things could be a bit better. But overall its all rather stuck in a rut!

[ANYWEATHER]

I don't think anything is set in stone yet for next week in regards to will we see a continuation of mild daytime temps or a fairly significent decrease in daytime temps to slightly below average and even single digit daytime figures.

The 06z and 12z GFS of yesterday showed the euro high further North and West giving more of a Easterly/South Easterly feed of air and progging daytime temps in single figures, yesterdays 18z then had the high further South and East putting us back in a more Southerly flow for next week, then surprise surprise the 00z GFS had us back in a Easterly/South Easterly feed, then LO and BEHOLD the 06z puts us back in a Southerly feed. It's as clear as mud still but I will maintain we have a 75% chance of a fairly significent decrease in daytime temps from Monday next week. Icindentally Weather Online update this morning goes for turning colder by the end of the weekend.

If you have a look at the latest H500 Northern Hemisphere chart from both the ecm and gfs , you will see the "cold well and trully locked up over the Pole even out to T+240. Jet stream is generally North Of the Uk , so general mild is the likely outcome IMHO....

[BLAST FROM THE PAST]

Just looking at the ECM spreads, a clustering of solutions suggesting a chunk of energy breaking off and heading southwards into the Atlantic to reinforce our omni-present trough to our west day 8 - certainly the DeBilt T2m ensembles have a grouping heading upwards from this point to very mild values for mid to late November, but also some cooler ones suggesting the high to remain in situ and draw in some cooler air. This upward trend might be a little progressive, but along the right lines I think.

For coldies, the one thing I would offer is that if we stay as we are with that ridge and trough arrangement, this would be a very positive signal for later on in the winter. Front loaded Nina winters are never good IMO (although last year was epic to start) and the fact that this autumn is along the lines of 1984 and 1995 which are somewhat atypical Ninas, this is a big, big bonus.

Interesting, But both brought different winter timings. '84 brought a mild Dec, bitter cold jan, cold Feb, '95 brought intense cold shots in Dec, mild Jan and cool/cold Feb. So on that basis a cold Dec/Jan are favoured?

I think and like the summary in RJS LRF that we may get the feeling that the weather doesn't know what it wants to do. Thus we may may well get this cold and then it resets to what we have to ing and fro ing for sometime.

All to play for IMO and certainly chances are there for decent cold shots. GFS 06z goes for the stalemate pattern right to the end, may be on the right track at present.

BFTP

Edited November 8, 2011 by BLAST FROM THE PAST

[Jeremy Shockey]

The updated MetO Day 16-30 wording seems to be indicating a colder spell into early December too. I havent observed this sort of language in recent times.

''By early December , temperatures are likely to return closer to average for the time of year , perhaps slightly below at times.''

Edited November 8, 2011 by Jeremy Shockey

[BLAST FROM THE PAST]

I wouldn't say the cold is well and truly locked up over the pole, just not near us. The jet does loop back up over the UK from the SW but it is well south of us over the Atlantic and then loops up over the top of us. Worth looking at the jetstream forecast tool. It could be horrendous with a PV driving a constant SW to NE flat pattern but that IMO is fortunately not the case.

BFTP

[Tim Bland]

It is worth noting that although not quite an outlier the GFS 06z is on the mild side of the ensembles with lots of members pushing -5 850's into the UK by the end of the run. This is a big improvement on the same run yesterday.

http://www.netweather.tv/index.cgi?action=charts;type=ens;sess=

[shedhead]

The updated MetO Day 16-30 wording seems to be indicating a colder spell into early December too. I havent observed this sort of language in recent times.

''By early December , temperatures are likely to return closer to average for the time of year , perhaps slightly below at times.''

Suddenly this looks like a straw to clutch, but what a difference 11 months make - imagine this outlook in late Nov last year, it would have gone down like the proverbial lead balloon...

[No Balls Like Snow Balls]

If you have a look at the latest H500 Northern Hemisphere chart from both the ecm and gfs , you will see the "cold well and trully locked up over the Pole even out to T+240. Jet stream is generally North Of the Uk , so general mild is the likely outcome IMHO....

Yes agreed we are still a long way off of getting -5 850hpa air over us and even 0c 850hpa air still seams a very long way off.

But I am talking short term, i.e. next week and I am talking about the orientation of the euro high being that it may bring a Easterly/South Easterly feed or a Southerly feed, this would be the difference between daytime temps of 13-15c and say 8-10c, may not sound a lot but i can assure you 8-10c after this mildness we have had would feel noticeably chilly.

[November13]

It is worth noting that although not quite an outlier the GFS 06z is on the mild side of the ensembles with lots of members pushing -5 850's into the UK by the end of the run. This is a big improvement on the same run yesterday.

http://www.netweathe...s;type=ens;sess=

I am more inclined to agree with the mountain forecast as they are usually bang on. No snow even for the high peaks. Mild then colder but dry is the outlook. Could be the first time the hills have been bare for the whole of November!

Planning Outlook: All mountain areas of Britain from Thursday, 10th November, 2011

For much of the next 10 days winds will blow from between south and east bringing generally above average

temperatures. Atlantic fronts will occasionally try and push in from the west but will weaken as they do so. One of these

will bring damp weather particularly to western ranges on Thursday and into Friday before a slightly more organised

band of rain and gale force southeast winds extends north late Friday. Subsequently high pressure over the north and

east of Europe should bring drier air with a better chance of sunshine returning. However still a threat of some showery

rain reaching mainly the Welsh mountains from the south at times

[ribster]

For those who'd like to see some snow this is the webcam from the Pic Du Midi De Bigorre, they have an observatory here and this actually helped NASA in the lunar landing.

It's just to my sw and is certainly worth a visit if you ever get down to this part of France.

http://www.bagn.obs-mip.fr/webcamV2/

Visited at the end of June, awesome place. There was still plenty of snow about too, especially on Taillon.

Anyway, I digress - back to the models...

[November13]

Edited..

Edited November 8, 2011 by Paul
Sorry, this is totally unrelated to the model output - please repost into the general weather thread or general winter thread.

[Backtrack]

Someone on YouTube who has a good understanding of model knowledge seems to think that lows will start to follow a more southern line and head into Spain and the Med.

Then also seems to say that the Euro high will move on top of the UK, bringing cooler SE'erly winds, followed by a low break down from the north bringing a cold breakdown with wintry showers for northern and western areas.

Could someone with a good understanding of the 500mb charts confirm this?

[bluearmy]

Someone on YouTube who has a good understanding of model knowledge seems to think that lows will start to follow a more southern line and head into Spain and the Med.

Then also seems to say that the Euro high will move on top of the UK, bringing cooler SE'erly winds, followed by a low break down from the north bringing a cold breakdown with wintry showers for northern and western areas.

Could someone with a good understanding of the 500mb charts confirm this?

its a possible solution over the next fortnight but requires the euro heights to retrogress to our nw, which will allow a northerly flow. this is the general solution from yesterday's ecm 00z which has been shown to be rather progressive, judging by the ensuing runs. at the moment, we look to have a general stalemate between the two main players - atlantic trough to our sw/sceuro heights to our east. could last a fair while yet.

[Timmytour]

1. Understandably, there's a drift back onto these threads from those looking for signs that this winter could live up or even exceed what last winter delivered in terms of cold and snow. At this point i have my hands up to signify that I am one such person.
   But though I read contrasting views from those whose knowledge and expertise in these matters I have the utmost respect for, I am always wary of the fact that we are still nowhere near knowing what our winter has in store for htree weeks ahead let alone the whole season of winter, howver many experrt guys gaze upon the models and the "patterns" they are showing.
   Here's a sobering prediction from 18th October last year........ http://www.netweathe...r-forecast;sess=
   
   • Anomalously cold ocean temperatures in the Tropical Pacific or La Nina conditions have become well established. There is a high probability that these conditions will intensify over the coming months and become one of the strongest La Ninas on record.
     
   • With a strong coupling between the atmosphere and ocean signal, global weather patterns are very likely to be forced by a strong La Nina with dominant high pressure centres in the northern Pacific and in the North Atlantic.
     
   • La Nina winters have a variable influence on the weather in Europe although we anticipate no sustained extremes of cold and the emphasis on dry, settled weather. Some wintry weather is however expected, particularly during mid to late December an early January.
     
   • Temperatures are likely to be close to or slightly below average with the coldest weather (relative to long term averages) centred over France and Iberia, the south-east of the UK closest to this cold. Compared to many winters of the last two decades, this coming winter would probably be regarded as cold although not of the same degree as last year or 2008/9.
     
     Netweather's Winter forecast did not really forewarn us of the joys (for cold lovers) that last winter bought.
     I'll have, as always, an intense interest in these thread. But the longer term predictions will neither get me excited in their cold ramping nor despondent in their mildness. I appreciate there are many experts out there......but nobody truly knows what winter as a season holds for us now, nor will know in three weeks.
     I'll enjoy and marvel at the knowledge behind the interpretations of what the models are showing in the long term.... but for the weather I'll stick to a minimum of a day and a maximum of ten!
     

Edited November 8, 2011 by Timmytour

[Backtrack]

its a possible solution over the next fortnight but requires the euro heights to retrogress to our nw, which will allow a northerly flow. this is the general solution from yesterday's ecm 00z which has been shown to be rather progressive, judging by the ensuing runs. at the moment, we look to have a general stalemate between the two main players - atlantic trough to our sw/sceuro heights to our east. could last a fair while yet.

Thanks for that bluearmy.

Really hoping that we do start to pick up on a major pattern change from the models soon. Frankly this one is boring me!

[snowfall09]

At what times does the GFS chart start rolling out ?

[Liam J]

At what times does the GFS chart start rolling out ?

At about 3.35pm this afternoon for the 12z, 9.35pm for the 18z

Edited November 8, 2011 by Liam J

[snowfall09]

At about 3.35pm this afternoon.

Thank you , fingers crossed

[Richard Lake]

I see the focus atm is very much on the mid-long term and not so much in the short term which I think is an oversight as things that happen in the short-term consequently have a knock-on effect.

Take this week for example, in the last few days GFS was progging deep oranges over us this week on the 850m temps and look what we have atm - just above average yes, but hardly mildly. Where is the sun? Seems set to continue throughout this week. I would not be surprised at all if the deep oranges progged next week will not materialise. I see a continuation of the cloud and mirk into next week with temperatures continuing to fall. Perhaps single digits countrywide. This in turn will have a knock-on effect on the following week. I think GFS is blind to see it atm - I think the ECM is taking this into account better.

In overview nothing to get excited about just yet - just a continual drop in average temperatures as we head through November.

Edited November 8, 2011 by djrikki

[ANYWEATHER]

I see the focus atm is very much on the mid-long term and not so much in the short term which I think is an oversight as things that happen in the short-term consequently have a knock-on effect.

Take this week for example, in the last few days GFS was progging deep oranges over us this week on the 850m temps and look what we have atm - just above average yes, but hardly mildly. Where is the sun? Seems set to continue throughout this week. I would not be surprised at all if the deep oranges progged next week will not materialise. I see a continuation of the cloud and mirk into next week with temperatures continuing to fall. Perhaps single digits countrywide. This in turn will have a knock-on effect on the following week. I think GFS is blind to see it atm - I think the ECM is taking this into account better.

In overview nothing to get excited about just yet - just a continual drop in average temperatures as we head through November.

The projected increase in temperature is still expected from tomorrow onwards. A fairly widespread 15c-17c is expected in Southern Britain during Thursday/Friday and beyond.....

[wolvesfan]

Hello All,

I've been looking at both GFS,ECM h500 northerh hemispere charts and though it seems clear about the pattern we're in at the moment i cant help but thinking that there are various windows of oppurtunity for the euro high to build further north.yesterdays ECM showed this and then droped it this morning,it could be wishful thinking on my behalf but i wouldn't be surprised if we dont see both models flirt with this again on the upcoming runs.

[Backtrack]

Just been put on a 7 day trial of Net Weather Extra full package - which is great btw.

Looked at the CFS, and if that model had its way we wouldn't have the 528 DAM line over the UK for more than a day during winter...

Edited November 8, 2011 by Backtrack

[johnholmes]

Someone on YouTube who has a good understanding of model knowledge seems to think that lows will start to follow a more southern line and head into Spain and the Med.

Then also seems to say that the Euro high will move on top of the UK, bringing cooler SE'erly winds, followed by a low break down from the north bringing a cold breakdown with wintry showers for northern and western areas.

Could someone with a good understanding of the 500mb charts confirm this?

not disagreeing with what ba has suggested but my own take on this.

I look fairly closely not only at what the 500mb anomaly charts are showing but how they actually perform subsequently. If they are consistent, all 3 of them, and largely agree with one another then, assuming none of the relatively short term teleconnections are not saying something different, AO, NAO and possibly the MJO, I usually reckon that the upper air pattern is going to be fairly similar to their 10-14 day prediction.

However, one still needs caution.

An example is occuring at the moment. All 3 have over a period of 5-8 days suggested that +ve heights are going to be around at 500mb over much of the northern hemisphere. This tends to suggest that the relatively mild weather we have had is about to change as the height build favours a change in the long wave pattern round the hemisphere.

The 3 charts 10 days ago had the western Atlantic trough well positioned but none of them has done very well with the upper ridge over and east of the UK.

I'll post charts shortly to show this.

Using the NOAA version see below

now look at the actual 500mb chart for the 7 Nov below

As you can see the eastern side is not very well predicted and the ECMWF and GFS versions were no better.

So I think its a wait and see game for a little while yet as to how the end of the month turns out. Do we get retrogression as ECMWF seems to suggest or the high setting up either over or a little to the NE of the UK.

From a view of less than 20% for a major wave shift a week ago to about 50% last evening (before I did this check) I'd say its back to 35-40% for the wave change to push deep cold air as opposed to shallow cold air over the UK. One of the 'clever' terms developed on here I hate is faux cold-for goodness sake describe it as it is, shallow surface cold!

On closer examination the ECMWF-GFS version did have a suggestion of theupper trough in the west extending east into the Med area, so just a hint there of what the 500mb actual shows, more so from ECMWF than GFS.

Edited November 8, 2011 by johnholmes

[shedhead]

1. Understandably, there's a drift back onto these threads from those looking for signs that this winter could live up or even exceed what last winter delivered in terms of cold and snow. At this point i have my hands up to signify that I am one such person.
   But though I read contrasting views from those whose knowledge and expertise in these matters I have the utmost respect for, I am always wary of the fact that we are still nowhere near knowing what our winter has in store for htree weeks ahead let alone the whole season of winter, howver many experrt guys gaze upon the models and the "patterns" they are showing.
   Here's a sobering prediction from 18th October last year........ http://www.netweathe...r-forecast;sess=
   
   • Anomalously cold ocean temperatures in the Tropical Pacific or La Nina conditions have become well established. There is a high probability that these conditions will intensify over the coming months and become one of the strongest La Ninas on record.
     
   • With a strong coupling between the atmosphere and ocean signal, global weather patterns are very likely to be forced by a strong La Nina with dominant high pressure centres in the northern Pacific and in the North Atlantic.
     
   • La Nina winters have a variable influence on the weather in Europe although we anticipate no sustained extremes of cold and the emphasis on dry, settled weather. Some wintry weather is however expected, particularly during mid to late December an early January.
     
   • Temperatures are likely to be close to or slightly below average with the coldest weather (relative to long term averages) centred over France and Iberia, the south-east of the UK closest to this cold. Compared to many winters of the last two decades, this coming winter would probably be regarded as cold although not of the same degree as last year or 2008/9.
     
     Netweather's Winter forecast did not really forewarn us of the joys (for cold lovers) that last winter bought.
     I'll have, as always, an intense interest in these thread. But the longer term predictions will neither get me excited in their cold ramping nor despondent in their mildness. I appreciate there are many experts out there......but nobody truly knows what winter as a season holds for us now, nor will know in three weeks.
     I'll enjoy and marvel at the knowledge behind the interpretations of what the models are showing in the long term.... but for the weather I'll stick to a minimum of a day and a maximum of ten!
     

Taken overall, last Winter was not particularly cold and certainly not as cold as the previous Winter. Whilst the NetW forecast did not pick up the extreme Dec, taking winter as a whole it was not far out, indeed if Dec had been anywhere even close to average the Winter would have been a massive let down for those who love cold.

Edited November 8, 2011 by shedhead

[Richie V]

The projected increase in temperature is still expected from tomorrow onwards. A fairly widespread 15c-17c is expected in Southern Britain during Thursday/Friday and beyond.....

Can't see It been anywhere this warm, thats bordering on crazy! Nearer 11 - 13C mabe a 14 somewhere.