Winter 2011/12 - General Discussion

[Liam J]

I wasn't aware of this. That is a fairly worrying piece of information alright. What about the prolonged cold spell of the previous winter? Was there any signal in advance about that by anyone?

The 'In Depth Technical Model output discussion thread' does not go back far enough to answer your question, this is how I found out just how early the signal for cold weather was picked up on last year, which was September.

Not good news so far, anything similar hasn't been observed for the coming Winter.

Edited October 25, 2011 by Liam J

[wolvesfan]

Hi all,i've been looking back at the models the gfs in particular on and around the 22nd oct last year.can anyone tell me if there are similaritys to the model runs we are seeing at present.thanks for any replies.

[Grimsby Snow Lover]

Hi all,i've been looking back at the models the gfs in particular on and around the 22nd oct last year.can anyone tell me if there are similaritys to the model runs we are seeing at present.thanks for any replies.

Hi mate, I've been doing the same thing too and to be honest I think they are more similar to charts from late September/early October 2010. This time last year they appeared to be more blocked with high pressure extending from Scandinavia to Greenland. Here is an example of a chart from late September 2010. http://forum.netweat...ttach_id=103962

Notice the Euro high with pressure lower in the Atlantic around Greenland/Iceland. I have a hunch that we will start to see colder charts around 3 to 4 weeks later than last year.

Edited October 25, 2011 by Grimsby Snow Lover

[karyo]

http://www.cpc.ncep....uT2mProbMon.gif

Some food for thought.

According to the CFS map I expect the source of the cold in December to be the Continent rather than from the north. In other words, cold and dry with the occassional easterly bringing snow showers in the east coast of England.

January is not so clear as even Iceland is having below average temperatures - this doesn't fit with the high pressure and the cold continental cold so maybe some polar maritime flow as well. Good to see Greenland above average on both Dec and Jan!

February looking overal mild with southwesterlies (look how cold Greenland looks feeding the Atlantic systems. Scotland may benefit here if it stays on the northern side of the jet.

Karyo

[Paul]

Stewart's (Glacier Point) early thoughts for the Winter, ahead of the full forecast (issued in November) can be viewed here:

http://www.netweathe...ghts-2011;sess=

[chionomaniac]

The 'In Depth Technical Model output discussion thread' does not go back far enough to answer your question, this is how I found out just how early the signal for cold weather was picked up on last year, which was September.

Not good news so far, anything similar hasn't been observed for the coming Winter.

It is still early days yet. Last year it wasn't until the start of November that stratospheric forecasts started raising a few eyebrows. If you had asked me at this time last year then I would have suggested that unless anything started to show soon then I would have serious concerns for winter as Jan and Feb played out pretty much as expected.

That is not the same for this year - as winter progresses it may become more uncertain forecastwise, especially if the westerly QBO eases out of the lower stratosphere allowing the dominant easterly QBO to disrupt the polar vortex.

My thoughts upto winter are of a very dominant positive AO and significant depressions initially affecting the NW but later crossing the country. At this point we will get an idea of weather the jet stream is going to follow suit with the last few years and follow a more southerly path. Certainly interesting after one has removed the craving for snow from the equation!

[A Winter's Tale]

Stewart's (Glacier Point) early thoughts for the Winter, ahead of the full forecast (issued in November) can be viewed here:

http://www.netweathe...ghts-2011;sess=

Very interesting to hear about a colder than average Febuary. Initial ideas expressed on that video and powerpoint sounds good to me.

[bobbydog]

going from GP's initial thoughts, it looks like this winter has the potential to be a reversal of the last two, with the colder weather coming later into winter. also with the conflicting signals regarding la nina, PV setup and the global angular momentum, i dont think anyone will really know how this winter will actually pan out until this time next month at the earliest

[Radiating Dendrite]

Very interesting.

But as we saw with summer forecast, a number of things could change.

I think GP will be closer to the mark this time

[Cheshire Freeze]

Excellent thoughts there by Stewart, a lot of respect for him for putting that together. He blows our knowledge and understanding out of the water and is the reason he is a fundamental spearhead of Netweather's forecasts.

From what I could gleen from that presentation, there is a lot of discrepency within the details of the signals for this year. The only thing that appears 'nailed on' is the Pacific ridge. The Scandi ridge looks potentially interesting to me and screams potential with just a few tweaks. The signal for February goes against what I have forecast but looking at this presentation there appears to be a case for a cold and snowy February- the likes of which we haven't seen for a fair while.

Great work Stewart

[Snowmad79]

Stewart's (Glacier Point) early thoughts for the Winter, ahead of the full forecast (issued in November) can be viewed here:

http://www.netweathe...ghts-2011;sess=

Wow very nice video there from GP, must say I appreciate him doing that and hope he could do a similar video update in a months time. Just watching that made his views on teleconnects a shed load more understandable for me so again thankfull.

So from what he said and showed, theres still to many conflicting signals to give a definitive outlook for winter just now but it looks like a Scandi high that may retrogress slightly towards Greenland will be the magor player this year with winter generally starting much later.

Kind of makes sense considering like Snow lover posted earlier about the current weather patterns seem 4 weeks or more later compaired with last year. Not to mention that the models the past few weeks have shown HP located near Scandi dominating overall, even showing some signs early last week of retrogression towards the GL area as well as ridging in the western atlantic.

Are we going to see a late winter with a proper Scandinavian HP beast and proper bone chilling siberian weather ?

PS. when was the last time we actually did have a proper Scandi High/ sustained siberian cold ?

[chionomaniac]

Thanks Stewart for your well presented initial winter thoughts. Interesting looking at the anomaly charts how strong the emphasis is for a Scandinavian ridge - far greater than I would have imagined. The Pacific ridge does look extremely likely though!

Good to see that you are going for a colder February as well - all eyes on any downwelling waves from the stratosphere come December hey?

[Grimsby Snow Lover]

Wow very nice video there from GP, must say I appreciate him doing that and hope he could do a similar video update in a months time. Just watching that made his views on teleconnects a shed load more understandable for me so again thankfull.

So from what he said and showed, theres still to many conflicting signals to give a definitive outlook for winter just now but it looks like a Scandi high that may retrogress slightly towards Greenland will be the magor player this year with winter generally starting much later.

Kind of makes sense considering like Snow lover posted earlier about the current weather patterns seem 4 weeks or more later compaired with last year. Not to mention that the models the past few weeks have shown HP located near Scandi dominating overall, even showing some signs early last week of retrogression towards the GL area as well as ridging in the western atlantic.

Are we going to see a late winter with a proper Scandinavian HP beast and proper bone chilling siberian weather ?

PS. when was the last time we actually did have a proper Scandi High/ sustained siberian cold ?

Was it not February 1991?

[bobbydog]

lets not read too much into that presentation, as was said in the text, its not a forecast, its the factors which have to be considered to make a forecast.

with things as they stand, there is the possibility of a colder feb.

as he says, there are conflicting signals at the moment so a solid forecast is very difficult to make. the models are showing little change at the moment, maybe this is because there is so much uncertainty as to which way these signals will go.

as it stands now, an early cold blast is looking unlikely but as they say, good things come to those who wait....

[Cloud 10]

Stewart's (Glacier Point) early thoughts for the Winter, ahead of the full forecast (issued in November) can be viewed here:

http://www.netweathe...ghts-2011;sess=

Many thanks to GP for putting that video together.

Must be a tough call to make between the two slightly different signals,although i would be quite content with a scandi high gradually migrating towards greenland!

[damianslaw]

Many thanks to GP for putting that video together.

Must be a tough call to make between the two slightly different signals,although i would be quite content with a scandi high gradually migrating towards greenland!

Agree a very good presentation it has to be said - lots of technical talk, but I think I followed most of it - though I got a bit lost during the discussion of GLAM. Must remember it is only a presentation explaining how some of the important factors which will determine the winter may play out. Interesting how there are conflicting signals between how the stratosphere is likely to play out and GLAM.

GP gave some initial thoughts of a more blocked pattern prevailing through Dec and Jan but then turning more unsettled in Feb and also mentioned a possibly average start to the winter but becoming pregressively colder - supporting some people's views that Feb will be the wintriest month. I do like the thought of strong heights remaining in situ over scandi during the first part of the winter - whilst it wouldn't necessarily promise a snowfest it would also suggest a fairly dry cool period of weather with lots of frost especially in the east with the west seeing some rain/snow at times, hopefully it wouldn't be too far east mind...certainly no suggestion of a zonal train of dross - perhaps the atlantic steam train will crash quickly come early-mid Dec it has never really gotten off the ground since well it last crashed in early Dec 2009 and we all know what happened then...

Edited October 25, 2011 by damianslaw

[Northern Block]

Wouldn't life be so much simpler if water froze at 5*C?

It would be interesting to see how the population of this thread compares over recent years. I'd hazard a guess that more people are visiting here earlier each year following recent good winters. This naturally leads to a longer period of time between viewing what outputs we have and the actual time period of winter. This can only cause greater uncertainty and worry that winter may hold hold what we all wish for.

Hopefully a few things will start to drop into place over the next 4-6 weeks and enjoy the rollercoaster till then.

[damianslaw]

Wouldn't life be so much simpler if water froze at 5*C?

It would be interesting to see how the population of this thread compares over recent years. I'd hazard a guess that more people are visiting here earlier each year following recent good winters. This naturally leads to a longer period of time between viewing what outputs we have and the actual time period of winter. This can only cause greater uncertainty and worry that winter may hold hold what we all wish for.

Hopefully a few things will start to drop into place over the next 4-6 weeks and enjoy the rollercoaster till then.

Yes people's expectations for the coming winter i.e. those hoping for deep cold and snow are probably the highest they have ever been in a generation given the exceptional start to last winter which is still vividly etched in the minds of most people. As a result I suspect more and more people than ever will be visiting such sites as this in the coming weeks just to see whether we are likely to see a repeat.

In some respects I wish we hadn't seen a winter start like last year as it would mean peoples' expectations would be much more realistic and the current projections of preety standard fare for November and the start of Dec would be taken with much less despair (by some not all it has to be said). Indeed I think a preety average Nov and early Dec with the atlantic ruling the roost bodes much much better for snow and cold prospects for the main part of the winter i.e. from mid Dec onwards than an early freeze up like last year - just how I always get a bit nervous when an exceptional spell of early summer occurs in April - early June - far too early I always think and not a good omen for the main part of the summer i.e. late June-Aug , this year being a classic example.

Perhaps the best advice is just to relax about the whole thing for the next 4 weeks and see where we are in a months time when things will start to become much clearer. I won't be giving my views until mid-late Nov.

[Aaron]

I'm just really looking forward to seeing the first flakes of snow fall.. I'll be like a little kid, you wait and see.

[phil nw.]

Certainly the suggestion by GP that the PV may be centred over Canada rather than Greenland increases the chances of Heights over Scandinavia at times.

However it would depend on the orientation of this High pressure as to whether we get the cold from further East.

A meridonal jet allowing some undercutting low pressure diving under the block would be one scenario although at this stage this is all speculation.

[Staffordshire]

That's last paragraph, cares simplifying?

Certainly the suggestion by GP that the PV may be centred over Canada rather than Greenland increases the chances of Heights over Scandinavia at times.

However it would depend on the orientation of this High pressure as to whether we get the cold from further East.

A meridonal jet allowing some undercutting low pressure diving under the block would be one scenario although at this stage this is all speculation.

[ITSY]

from what i understand:

dryer than normal

around average most of the time

HP for Dec and Jan in control - explaining the dryness and average temps (higher by day, lower by night presumably)

colder and wetter for February.

=> opposite to last year basically. with the extremes at both ends of winter not as severe!

[Liam J]

So things don't look good for early winter is what I gathered, The fact he mentioned that northern blocking looks unlikely this year until mid-late winter, and also that the polar vortex is forecast to set up over Northern Canada can't be the best outlook in terms of wintry weather for the UK? Last year the polar vortex was displaced well south over NW Europe and the UK. It may be a long wait for any decent cold to build up and any HP over Scandinavia would have to have some suitable cold to tap into over Eastern Europe.

1) High latitude blocking unlikely to be sustained until late January or February

2) Polar vortex located over Northern Canada

3) Possible support for blocking ridge over Scandinavia

4) High potential for major mid winter warming timed early or mid February

Alot to take into consideration here, I certainly wouldn't like to be trying to draw a definate conclusion from all of the data and to then compose a winter forecast!

Edited October 25, 2011 by Liam J

[Aaron]

Well, that's good, contain the wintry weather to the core winter months (Jan and Feb), plus avoiding any chaos during the Christmas period like last year

[legritter]

just a quicky . just enjoyed 13 days of touring uk . sun 9th oct to friday 21 st oct . mostly scotland . wed 12th oct we travelled up west coast of scotland wester ross and the view across to sky was amazing , it was very warm ,blue sky blue sea . thurs friday was spent on sky ,overcast windy sat and sunday north of scotland , fantastic waves surfers .on monday we travelled down to perth ,wewent from heavy rain to SNOW yes SNOW . but it was very brief and almost sleet this was round about devils elbow mid afternoon , the following morning we drove to clamis castle . and in the distance on the high mountains we could see the snow topped peaks . on the way back we stopped at scarborough 2 days we had a hail shower . all in all weatherwise very interesting ,cheers legritter somerset