Winter 2012 / 2013 Part 2

[Village]

But look at the 06 CFS and you see something very different, although a fair winter it would still be.This sea ice domino effect, well I'm not sure it will lead to anything, I think its just part of the ongoing cycle. I mean the jet has been very meridional and shifted south for several years now, so if it is very disrupted, south, meridional then it isn't because of the sea ice situation this year? If so much ice has melted and Greenland is melting then how come SST anomaly is so warm around Southern Greenland. Melted ice is errrrr cold water? I'm taking that with a pinch of salt, and at best part of the ongoing process/cycle we are in.BFTP

It is more likely to have a southerly misplaced jet if the sea ice is less IMO. The reason is that if more Arctic sea is exposed to the atmosphere then there will be a tendency for lower atmospheric pressure in the Arctic. That gives rise to high pressure cells at our lattitude creating the blocking paterns IMO. As for cold fresh water!! forget it....the ice melt water will be at sea temperature within hours so wont influence the weather. SST's should be warmer in southern Greenland if there has been a predominantly southerly component due to a persistent mid Atlantic high .

[Aaron]

Winter has already started in Scotland.

Earlier this week it was snowing on the mountains in Scotland and over the next 24 hours it is set to fall below freezing for ten of these hours in inland areas like Tulloch Bridge for instance. Temps will drop as low as minus 3 celcius.

Tonight should see air frost in northern England and North Wales, wouldn't be surprised to see the likes of Benson fall below freezing too.

[Met4Cast]

I suppose you could try and link the run of three cold winters with the 2007 record ice melt, assuming there's a slight lag time. This would be I suppose the ice melt this year would have no effect on our weather, but the next two years could be very cold as a result.

Of course the weather doesn't quite work like that, it's far more complex, but it does seem like it could be more than a coincidence that after we saw a record breaking Ice Melt in 2007, we saw a run of cold winters begin..

Edited September 21, 2012 by Daniel AKA WMD

[Karl83]

Can anyone advise where I can find last years model predictions or does anyone know what was being shown this time last year?

[Suburban Streamer]

But look at the 06 CFS and you see something very different

part and parcel of watching cfs 9month runs!

as for the 0z....forget the bank, i'm just gonna quietly stash that under my mattress

[Methuselah]

It is more likely to have a southerly misplaced jet if the sea ice is less IMO. The reason is that if more Arctic sea is exposed to the atmosphere then there will be a tendency for lower atmospheric pressure in the Arctic. That gives rise to high pressure cells at our lattitude creating the blocking paterns IMO. As for cold fresh water!! forget it....the ice melt water will be at sea temperature within hours so wont influence the weather. SST's should be warmer in southern Greenland if there has been a predominantly southerly component due to a persistent mid Atlantic high .

I agree Village, and for much the same reasons you cite. I also agree that there is a pronounced cyclic influence, a la Fred's post...But it's the disappearing sea-ice that's the greatest unknown quantity here, I think. It could even have sufficient influence on the Jet, of itself, to cause major shifts in weather patterns. Conversely, any effect it has could turn-out to be negligible...

At this stage, who knows?

[BornFromTheVoid]

I suppose you could try and link the run of three cold winters with the 2007 record ice melt, assuming there's a slight lag time. This would be I suppose the ice melt this year would have no effect on our weather, but the next two years could be very cold as a result.

Of course the weather doesn't quite work like that, it's far more complex, but it does seem like it could be more than a coincidence that after we saw a record breaking Ice Melt in 2007, we saw a run of cold winters begin..

The difficulty with drawing a direct comparison like that, is that in 2007 we also saw a switch to a -ve PDO. In 2008 the low solar minimum really began to take hold, and recent years have been dominated by La Nina.

It's probably a combination of them, and a few other things (QBO, Stratosphere, etc) that caused some of the cold winters of late.

I'm working on a little bit of research on the link between the sea ice and the PDO, so it may be even more complicated!

[johnholmes]

I think we can all take it as read that trying to predict a season ahead is immensely complicated, be that for winter or any other season.

If that were not the case then the main centres, US, UK and ECMWF would already be predicting with reasonable accuracy and they obviously are unable to do that.

It is hugely complicated as the model thread and Atlantic storm threads are showing when predicting just 48 hours ahead has the models in something of a spin. Quite why, as I've commented in threads this morning, weather systems running in from the south give models so much difficulty is hard to understand but it does.

Why on earth is it likely to be any less compicated to trying to predict the overall weather pattern 2-3 months in advance?

[Suburban Streamer]

Can anyone advise where I can find last years model predictions or does anyone know what was being shown this time last year?

this time last year was not looking great in terms of background signals. perhaps a good place to go is the stratosphere thread from last year.....following that thread last year, it became very apparent from a fairly early stage that our winter was unlikely to get off to a good start and that any cold would come following a strat warming event mid jan, despite several predictions from other people saying december would be cold and snowy.

cfs is the only model going out that far and should be taken with several pinches of salt at this stage.....enjoy the pretty pics and keep your fingers crossed!

i do feel much more positive than i did this time last year, but that's not really anything to do with the cfs or any model at this early stage tbh.

http://forum.netweather.tv/topic/71340-stratosphere-temperature-watch-20112012/

Edited September 21, 2012 by Suburban Streamer

[Moomin71]

I think we can all take it as read that trying to predict a season ahead is immensely complicated, be that for winter or any other season.

If that were not the case then the main centres, US, UK and ECMWF would already be predicting with reasonable accuracy and they obviously are unable to do that.

It is hugely complicated as the model thread and Atlantic storm threads are showing when predicting just 48 hours ahead has the models in something of a spin. Quite why, as I've commented in threads this morning, weather systems running in from the south give models so much difficulty is hard to understand but it does.

Why on earth is it likely to be any less compicated to trying to predict the overall weather pattern 2-3 months in advance?

.

Not a meteorological modeller myself but I do model groundwater frequently and it is very interesting what the models can and cannot handle easily. it must be highly senstive to some parameter(s) that are present/interact differently coming from the south as opposed to SW or W. Perhaps the way in which the models are configured doesn't have the continental effects from Europe quite right, would love to understand the models more.

M

[Karl83]

this time last year was not looking great in terms of background signals. perhaps a good place to go is the stratosphere thread from last year.....following that thread last year, it became very apparent from a fairly early stage that our winter was unlikely to get off to a good start and that any cold would come following a strat warming event mid jan, despite several predictions from other people saying december would be cold and snowy.

cfs is the only model going out that far and should be taken with several pinches of salt at this stage.....enjoy the pretty pics and keep your fingers crossed!

i do feel much more positive than i did this time last year, but that's not really anything to do with the cfs or any model at this early stage tbh.

http://forum.netweat...watch-20112012/

Thanks I will check it out.

[Chris K]

Is that all you've got?

There are no limitations... ramp away!

Anyway, I really dont know what this winter will bring, but as long as it isn't constant benign grey skies...I'll be happy.

[TEITS]

I think we can all take it as read that trying to predict a season ahead is immensely complicated, be that for winter or any other season.

If that were not the case then the main centres, US, UK and ECMWF would already be predicting with reasonable accuracy and they obviously are unable to do that.

It is hugely complicated as the model thread and Atlantic storm threads are showing when predicting just 48 hours ahead has the models in something of a spin. Quite why, as I've commented in threads this morning, weather systems running in from the south give models so much difficulty is hard to understand but it does.

Why on earth is it likely to be any less compicated to trying to predict the overall weather pattern 2-3 months in advance?

Big difference though between trying to predict the exact details of the next 48hrs compared to looking at the overall pattern for a forthcoming season. At this stage nobody is making any detailed predictions but looking to see if the signals favour a blocked or mobile weather pattern. This is a completely different type of Meteorology and cannot be compared.

Personally im not getting excited at the moment and shall wait another 6 weeks and hope the favourable signals continue.

[BLAST FROM THE PAST]

Because the area has been dominated by high pressure for the last few months, allowing the sun to raise the SSTs.

I don't buy that, as that suggestion shows that HP was in place before the SSTs...so which drives what? I suppose it shows there's many pieces to the puzzle.

BFTP

Edited September 21, 2012 by BLAST FROM THE PAST

[BLAST FROM THE PAST]

I suppose you could try and link the run of three cold winters with the 2007 record ice melt, assuming there's a slight lag time. This would be I suppose the ice melt this year would have no effect on our weather, but the next two years could be very cold as a result.

Of course the weather doesn't quite work like that, it's far more complex, but it does seem like it could be more than a coincidence that after we saw a record breaking Ice Melt in 2007, we saw a run of cold winters begin..

-ve PDO, perturbation cycle all in place before the 'minor timescale record low' ice amount. The ice break up this year was also very much so affected by the 'unprecedented' summer arctic storm.BFTP

[Methuselah]

-ve PDO, perturbation cycle all in place before the 'minor timescale record low' ice amount. The ice break up this year was also very much so affected by the 'unprecedented' summer arctic storm.BFTP

So was all that man-made atmospheric CO2...

[CanadaAl]

Just wondering, why is there a part 2? Does netweather have a 36 page quota?

[Radiating Dendrite]

Just wondering, why is there a part 2? Does netweather have a 36 page quota?

No. It just gets a bit large when a thread goes too long.

This keeps it all nice and concise, otherwise we would have 1000+ page long threads.

[BornFromTheVoid]

I don't buy that, as that suggestion shows that HP was in place before the SSTs...so which drives what? I suppose it shows there's many pieces to the puzzle.

BFTP

I would be of the opinion that the high pressure caused the warm anomalies in this instance at least. It makes sense to me?

-ve PDO, perturbation cycle all in place before the 'minor timescale record low' ice amount. The ice break up this year was also very much so affected by the 'unprecedented' summer arctic storm.BFTP

The record low was not minor. Based on the current evidence, it was the lowest in 8,000 years, possibly much longer.

Getting into the cause of the record minimum and the influence/relevance of the August storm is a debate for elsewhere though, but just to say, the ice was well on it's way towards lowest on record even before the storm.

The newly open waters in the Arctic allow for a rapid heat build up in Summer and subsequent release in the Autumn and early Winter. This affects the thermal and thickness gradient between the Arctic and the tropics, one of the fundamental causes of all weather. This change simply has to affect our weather in some way. The difficulty is teasing out the strength of that influence from the other drivers already mentioned, but mainly the low solar activity and -ve PDO.

[Mr.Plow]

I have heard it mentioned that there is a tendency for lower pressure where the ice has gone. Could that aid deveopment of Polar lows?

[BornFromTheVoid]

I have heard it mentioned that there is a tendency for lower pressure where the ice has gone. Could that aid deveopment of Polar lows?

Not necessarily the tendency for lower pressure, but as the air cools rapidly and we get 850hPa temperatures down around -20C while the sea surface is still around 0C, the temperature differential will help with their formation at higher latitudes. Unfortunately, I don't see it helping to produce anything more further south.

[Methuselah]

I would be of the opinion that the high pressure caused the warm anomalies in this instance at least. It makes sense to me?

The record low was not minor. Based on the current evidence, it was the lowest in 8,000 years, possibly much longer.

Getting into the cause of the record minimum and the influence/relevance of the August storm is a debate for elsewhere though, but just to say, the ice was well on it's way towards lowest on record even before the storm.

The newly open waters in the Arctic allow for a rapid heat build up in Summer and subsequent release in the Autumn and early Winter. This affects the thermal and thickness gradient between the Arctic and the tropics, one of the fundamental causes of all weather. This change simply has to affect our weather in some way. The difficulty is teasing out the strength of that influence from the other drivers already mentioned, but mainly the low solar activity and -ve PDO.

I would agree with all of that, BFTV...I'd even go as far as to ask: what drives the PDO? Some kind of homoeostatic response/feedback mechanism, in response to the planet's ever-changing heat distribution, would be my best guess...Which is why I, personally, do not see it as a primary driver, as of itself? Although, it's undoubtedly a valuable indicator of current conditions.

[Excitable_Weatherwatcher]

IMPORTANT this weather website has info on winter 2012 /2013 and it talks about the affect of Arctic melt. http://ukweather.wordpress.com/winter-201213/

[Barry12]

IMPORTANT this weather website has info on winter 2012 /2013 and it talks about the affect of Arctic melt. http://ukweather.wor.../winter-201213/

The same site which got last winter completely wrong.

[UV-RAY]

I would be of the opinion that the high pressure caused the warm anomalies in this instance at least. It makes sense to me?

The record low was not minor. Based on the current evidence, it was the lowest in 8,000 years, possibly much longer.

Getting into the cause of the record minimum and the influence/relevance of the August storm is a debate for elsewhere though, but just to say, the ice was well on it's way towards lowest on record even before the storm.

The newly open waters in the Arctic allow for a rapid heat build up in Summer and subsequent release in the Autumn and early Winter. This affects the thermal and thickness gradient between the Arctic and the tropics, one of the fundamental causes of all weather. This change simply has to affect our weather in some way. The difficulty is teasing out the strength of that influence from the other drivers already mentioned, but mainly the low solar activity and -ve PDO.

Actually it was 2000 years ago not 8000 and I really can't see how you can attribute this to CO2 levels, the jury is still out on that one.