Model Output Discussion - 7th-13th November

[No Balls Like Snow Balls]

I have been reading about Global Wind Oscillation (GWO) and Atmospheric Angular Momentum (AAM) and would I be right in saying that a high AAM can lead to a cold wet/snowy winter in Western Europe?. Sometimes the way things are written can make things sound sooooo complicated.

I suppose that I should say that rather than a whole winter I should say period instead?.

So in what i have gleaned from the readings I can I assume that a high AAM phase can lead to an increase in low pressure to the East of the UK bringing colder conditions from the East? and a low AAM phase can lead to an increase of mid latitude blocking i.e. a high centered close to or over the UK bringing us dry and mild southerly winds?

Edited November 8, 2011 by No balls like Snow Balls

[Timmytour]

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.

:-)

I'd say to miss out a whole month of winter was quite a big thing to miss from a forecast.....especially as it was remarkable (not unique) in its severity.

And of the three seasonal months it was the nearest one for which the forecast went amiss. I'm not saying it missed by a million miles....but I'm sure that in December there were forecasts for the remain of winter that were more severe than it actually turned out to be.

Attempting to predict long term from the models is good fun and makes for fascinating reading.......,but the truth is we don't know what three weeks time will bring.... fingers in the wind stuff probably proves almost accurate as poring over the interaction of the models. .

[Paul]

We're heading way off topic here - there are several other threads to discuss winter forecasts and the like..

[Backtrack]

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.

Wow a fantastically informative post. Thanks a lot for that John.

[cyclonic happiness]

The term "faux cold" annoys the dickens out of me too! it's either cold or it isn't, the only time you'd expect to have faux cold is when struck down with the 'flu and having the shivvers etc.

Back to the models, the GFS and ECM and other are having difficulty with the pattern change and there will be one, the weather can't stay in the same rut for months!

I think we should just all stop looking too deeply at things and wait for the creases to be ironed out.

We need not hand out the cyanide pills until at least late december

[A.J]

the first few frames of the 12z GFS run are just trickling out, but I'd like to post on the 06z run (haven't had chance to review model runs the past few days).....Anyhoos, I digress, talk about groundhog day! The entire run can be summed up with the sentence 'Southerly flow and generally mild) yes a cooler spell briefly in mid FI before warmer uppers flood northward towards the end of the run....That Euro high does a fantastic job in just sitting there recycling, generally causing cold rampers on here to have manic depressive bouts bordering on insanity...lol and the ECM 00z also has charts throughout the run showing air patterns with a southerly component to them, so TBH I feel that there is little point in people constantly alluding to pattern changes...Yes a pattern change will come, it's the weather after all, but constantly looking for a 'cold solution' in charts that are about as mild as mild can be, frankly smacks of desperation to me!

[Harsh Climate]

the first few frames of the 12z GFS run are just trickling out, but I'd like to post on the 06z run (haven't had chance to review model runs the past few days).....Anyhoos, I digress, talk about groundhog day! The entire run can be summed up with the sentence 'Southerly flow and generally mild) yes a cooler spell briefly in mid FI before warmer uppers flood northward towards the end of the run....That Euro high does a fantastic job in just sitting there recycling, generally causing cold rampers on here to have manic depressive bouts bordering on insanity...lol and the ECM 00z also has charts throughout the run showing air patterns with a southerly component to them, so TBH I feel that there is little point in people constantly alluding to pattern changes...Yes a pattern change will come, it's the weather after all, but constantly looking for a 'cold solution' in charts that are about as mild as mild can be, frankly smacks of desperation to me!

Hmmm I disagree about a southerly flow been terribly bad in terms of hoping for cold in the future. Also it could be much worse, a mobile atlantic flow with depressions sweeping in from the south west heading all the way across northern europe. Thats the type of set-up where it could be stuck in a rut for a long time for snow fans..

A lot of great winter set-ups in the past have occured right after a southerly, probably due to the WAA been brought right up the northern hemisphere, aiding pressure rises towards greenland or svalbard.

I think the key indicators at the moment of any possible upcoming snow/cold are The ''NAO/AO predictions'', the atlantic becoming less active and a gradual cooling trend to the east, all of these ingredients seem to slowly falling into place. I expect a wintry spell of weather late november, probably nothing like last year but an early start to winter none the less

Edited November 8, 2011 by Harsh Climate

[trisnow]

anything interesting in the 12z's?

[ANYWEATHER]

anything interesting in the 12z's?

Well if you like Mild weather ,Its a Superb Run!!!

[mountain shadow]

Nothing in the GFS 12z, the T+0 chart is as good as identical to the T+240.

I thought a pattern change was in the offing?

[Slowpoke]

No-one seems to be realising how amazing these charts would be in say July/August??!!

[Radiating Dendrite]

No-one seems to be realising how amazing these charts would be in say July/August??!!

Yep.

I would imagine we would be looking at a record month on the CET with endless winds off the continent if this was July/August.

Maybe GP should just reissue his summer forecast as the winter one!

Anyway........agree with Mountain Shadow, pretty uninspiring charts for cold weather fans. We just seem stuck at the moment, with little to force us out of this current pattern teleconnection and stratosphere wise.

Edited November 8, 2011 by Radiating Dendrite

[phil nw.]

No-one seems to be realising how amazing these charts would be in say July/August??!!

I think we do but i think most are looking for Winter charts Slowpoke.

Meanwhile GFS and UKMO12z continues with same picture-the 2 main features ie,Atlantic trough and Euro High are stubborn beasts.

Rinse and repeat.

[Cecil Hogmanay Melchett]

Boring model runs at the moment nothing interetsing to see on the models.

Anyone seen TEITS yet he's usually here by Novemeber hope he's ok.

[Rocheydub]

At the end of GFS it shows a new high pressure and the Atlantic low pushing the euro high north and west, probably not how it will pan out at all as it's over 300 hours, but I'd like to see ECM and ukmo come on board with this idea....

[Summer Sun]

No-one seems to be realising how amazing these charts would be in say July/August??!!

Record breaking temperatures would not be out of the question that's for sure, back to now great charts for those wanting the warm weather to continue no signs of any breakdown tonight

Deep FI gives the impression of a change

http://www.wetterzen...s/Rtavn3601.png

But then this arrives

http://www.wetterzen...s/Rtavn3841.png

:good:

Those charts are not what James Madden will want to be seeing.

[Cecil Hogmanay Melchett]

Record breaking temperatures would not be out of the question that's for sure, back to now great charts for those wanting the warm weather to continue no signs of any breakdown tonight

Deep FI gives the impression of a change

http://www.wetterzen...s/Rtavn3601.png

But then this arrives

http://www.wetterzen...s/Rtavn3841.png

:good:

Those charts are not what James Madden will want to be seeing.

at 384 h im not sure they will happen anyway gavin.

BUT the outlook is a zzzfest for sure.

[snowfall09]

This may sound stupid but is it possible for Europe to cool down by itself, when i say by itself i mean without the movement of artic air filtering down to cool down europe.

So for example lets just say that euro high was stuck over Europe until December would we see Europe cool down quite dramaticly under clear skies and not much movement of air?

If so then does the gfs actually take that into account??

Edited November 8, 2011 by snowfall09

[Summer Sun]

This may sound stupid but is it possible for Europe to cool down by itself, when i say by itself i mean without the movement of artic air filtering down to cool down europe.

So for example lets just say that euro high was stuck over Europe until December would we see Europe cool down quite dramaticly under clear skies and not much movement of air?

If so then does the gfs actually take that into account??

A lot would depend on wind direction and cloud cover I think, if Europe got a warm southerly wind then day's could be warm but nights would be cold if the sky's were clear.

Edited November 8, 2011 by Gavin D

[carinthian]

No-one seems to be realising how amazing these charts would be in say July/August??!!

They are amazing now as well. This Autumn continues with its prolonged conveyor of warm African air masses across much of Western and Central Europe. Has anyone reported a frost yet in Southern Britain ? So it seems ,no immediate changes on the horizon. Bad news for us in the ski resorts as we are due to open for business in less than 3 weeks. At this rate the heating suppl,y companies will have to discount , just for you to even turn on the heating... not up !

These long range charts showing the same type of now even getting a bore in Austria if its any consolation to you cold lovers.

C

[rich1]

Record breaking temperatures would not be out of the question that's for sure, back to now great charts for those wanting the warm weather to continue no signs of any breakdown tonight

Deep FI gives the impression of a change

http://www.wetterzen...s/Rtavn3601.png

But then this arrives

http://www.wetterzen...s/Rtavn3841.png

:good:

Those charts are not what James Madden will want to be seeing.

Hmm...fee fi fo fum....or who's that trip trapping across my bridge? ;-)

but it does look very dull viewing right now, have to say, but not that unexpected at this time. Only real positive is that at least it isnt that wet on those. Having these charts for the christmas period would be about as much fun and as seasonal as a kidney infection. As it is, my hopes for this month are not that high but it cant last forever

were a few charts that suggested a change on earlier runs, I hope they re-emerge, things can change and they have done before. Actually the cold can wait until december for me, as it did in 2009 where the pattern in november was worse, with an active atlantic and incessant rain

my advice is probably come back in a few days, maybe a week, and maybe it will look more interesting. In the summer these would be fab but right now they are pretty, well, flab

cant see the fascination with mid teen temps at any time of year to be honest though. Though maybe the air will turn cooler over time, but anything exciting looks a distance away

[SLEETY]

Record breaking temperatures would not be out of the question that's for sure, back to now great charts for those wanting the warm weather to continue no signs of any breakdown tonight

Deep FI gives the impression of a change

http://www.wetterzen...s/Rtavn3601.png

But then this arrives

http://www.wetterzen...s/Rtavn3841.png

:good:

Those charts are not what James Madden will want to be seeing.

Well considering we are only in the 2nd week of November I shouldn't think he is too worried about his forecast for the whole winter yet.

Can't see why people are so keen anyway for extremly cold weather sypnotics at this time of year,unless of course conditions like we had last year are a common feature of November :lol:

Much rather see the cold weather spynotics develop at least 6 weeks down the line instead of seeing the end of the cold weather like we did last year.

[Grimsby Snow Lover]

Well after a fairly disappointing 12z GFS regarding possible cold I was hoping for the ensembles to show it was an outlier. Unfortunately the run seems pretty bang on as it follows the mean for just about the entire run until the usual FI charts appeared at the end.

Lets hope the ECM backs up its regression from yesterday later on.

[Gowon]

They are amazing now as well. This Autumn continues with its prolonged conveyor of warm African air masses across much of Western and Central Europe. Has anyone reported a frost yet in Southern Britain ? So it seems ,no immediate changes on the horizon. Bad news for us in the ski resorts as we are due to open for business in less than 3 weeks. At this rate the heating suppl,y companies will have to discount , just for you to even turn on the heating... not up !

These long range charts showing the same type of now even getting a bore in Austria if its any consolation to you cold lovers.

C

We had a couple of frosty mornings back in October, can't remember the dates though.

Things look like cooling down a touch next Monday onwards as we pull in a South Easterly.

[BlueHedgehog074]

Looks like the GFS is becoming keen to put us near da radiator again (rather than close to da fridge or freezer), with a generally milder outlook compared to recent runs. Eastern areas particularly should loose the drizzly influence as winds start backing from more of a Southerly direction and bring up some clearer skies over the next few days. The sunniest and driest conditions most likely in the East with the West likely to see a bit more in the way of cloud.

Then looks like from the weekend onwards, places should start becoming less mild as the winds start becoming more South-Easterly, but with the High-Pressure to the East still sitting stubbornly:

I do feel that next week is still not nailed properly yet as the 00Z ECMWF from Sunday onwards, shows winds having a little bit more of an Easterly influence (as High-Pressure from the East tries to ridge in further Westwards) compared to the GFS. And I imagine the ECMWF chart would be a little more cooler too.

In further FI, the 12Z GFS and 00Z ECMWF do try to push the block further East/South-East. GFS, especially, shows the pattern of Low Pressure systems from the West trying to crash through further East. Only one problem with this is the GFS has shown this to be the case a few times before and then removes this idea. As such, I do believe they are being too progressive with this.

I agree with others that this pattern is unlikely to last forever, and its possible GFS may bring back more of the Easterly influence on its next runs... although the High-Pressure to the East may have a hard time retrogressing North-Westwards with Low Pressure to the West, and with the fact there's also a lot of energy going over that High-Pressure.

An example of this from the GFS chart next Tuesday (circles indicating the Low Pressure systems and energy going over the High):

Edited November 8, 2011 by Rainbow Snow