The Run Up To Winter 2011/2012- Signs Of A Cold/mild Winter And The Autumnal 'building Blocks'

[summer blizzard]

Fascinating stuff, especially considering how the graphs appear to be well matched at the beginning and end. What made you choose 11 year blocks? It would be interesting to know what effect increasing the number of years in the blocks of data would have, e.g. I wonder if a block of 15 years would return more accurate results than a block of 10, and that would be more accurate than a block of 5?

Would it not have been more effective to only include the 11 year periods where solar activity was increasing. I only say because both December 2007 and January 2005 saw decreasing solar activity.

[VillagePlank]

The choice of 11 years is arbitrary.

I had to take a punt, and the ~11 year solar cycle seemed as good as any. There is a balancing act going on here. As you use more years for pattern matching the covariances go seriously down for reasonably obvious reasons - the chances of matching all the ups and downs over, say, 100 years, is very very slim - and even the results you get suffer from a kind of compression, so that a covariance of 0.024 is radically different from one of 0.025 - when, in reality, the results would mean radically different winters.

On the other hand if you pick, say, 3 years, then you get an awful lot of matches which clearly, by reason of the domain of enquiry, is not very helpful.

What's going on here is maximising the linear separation of classes [1] by arbitrary guesswork. Ideas for future work (I've just had a vasectomy, so pretty slow on the uptake at the minute) is to derive the years back parameter by genetic algorithm [2], or gradient descent[3]

I've tried to explain the mechanics of how I did in my blog in my signature; it's mainly a programming blog, which I've just started, so that might put some off.

The thing to remember on this is that it is pattern matching - ie the form of the winter (which months will be warmer than others) and given that this is my first attempt at such a seasonal forecast, success or failure, in my view will be that I got the temperature ranking of the months correct, not the temperature itself.

[1] http://en.wikipedia....minant_analysis

[2] http://en.wikipedia....netic_algorithm

[3] http://en.wikipedia....radient_descent

Edited November 4, 2011 by Sparticle

[virtualsphere]

The choice of 11 years is arbitrary.

I had to take a punt, and the ~11 year solar cycle seemed as good as any. There is a balancing act going on here. As you use more years for pattern matching the covariances go seriously down for reasonably obvious reasons - the chances of matching all the ups and downs over, say, 100 years, is very very slim - and even the results you get suffer from a kind of compression, so that a covariance of 0.024 is radically different from one of 0.025 - when, in reality, the results would mean radically different winters.

Thanks for replying, I'd not thought of the solar cycle so from that perspective 11 years seems like a good choice. I like the idea of using a statistical model for pattern matching; it will be interesting to see how that pans out and whether, even if the actual temperatures are out, the temperature progression through the winter follows a similar line to your graphs as well as which months are coldest.

It's a shame in a way there isn't more data to work with - it would be good to try something like this out using larger blocks with data from the last 1000 years to include different periods of weather and solar activity!

[VillagePlank]

Access to data is always a problem. Perhaps not so much now, that climate sets are available online. The CET is convenient firstly because I live in England, and secondly it is a good quality source of info.

[BLAST FROM THE PAST]

I was actually really looking forward to your forecast BFTP :/

Kind words and thanks to many. I haven't had the time this year and is largely a part to do with it and I could get one out in time if I pushed it but am inclined not to. Having said that, I do 'like' the rhythm of RJS forecast and so look at that for good similarities to my thoughts. I do propose to do monthly outlooks though with detail to pinpoint weather events of note and I do repeat that a big change is still strongly a possibilty for much colder conditions with winds from N to E quadrant during the period of last week of Nov. This proposed change is solar and lunar driven IMO and I believe there are now tentative signs appearing teleconnection wise and long range model output suggesting this possibility.

BFTP

Edited November 6, 2011 by BLAST FROM THE PAST

[mcweather]

Kind words and thanks to many. I haven't had the time this year and is largely a part to do with it and I could get one out in time if I pushed it but am inclined not to. Having said that, I do 'like' the rhythm of RJS forecast and so look at that for good similarities to my thoughts. I do propose to do monthly outlooks though with detail to pinpoint weather events of note and I do repeat that a big change is still strongly a possibilty for much colder conditions with winds from N to E quadrant during the period of last week of Nov. This proposed change is solar and lunar driven IMO and I believe there are now tentative signs appearing teleconnection wise and long range model output suggesting this possibility.

BFTP

Hi BFTP, I too am sorry to hear that you will not be doing a seasonal forecast this year but I don't blame you the peculiarly British tendency to find any reason to criticise rather than congratulate rears it head far too often in these forums. People decide to call a forecast a busted flush if it has not lined up by Dec2nd rather than wait until the end of feb to see which pieces worked and which if any didn't.

I concur with you as well on a major pattern shift to cold or very cold in late nov or early dec. This also ties in very well with the ECM 32 day long range output as confirmed by Matt Hugo over on TWO on friday and as we are always being told that ECM is the best and most reliable model I see no need to change from that view at the moment.

Edited November 6, 2011 by mcweather

[BLAST FROM THE PAST]

Hi BFTP, I too am sorry to hear that you will not be doing a seasonal forecast this year but I don't blame you the peculiarly British tendency to find any reason to criticise rather than congratulate rears it head far too often in these forums. People decide to call a forecast a busted flush if it has not lined up by Dec2nd rather than wait until the end of feb to see which pieces worked and which if any didn't.

Indeed. Good luck to all that have, let's see how they pan out.

BFTP

[No Balls Like Snow Balls]

Looking at the longer term picture for the whole of winter what we are seeing now must be good for the future winter months. Basically we are awash with high pressure, ok so it's not in the right place at this minute but eventually we will hit the jackpot, it is the law of averages that tells us this, if we see a continuation of high pressure dominated weather through the whole of winter i think we will have a cold and fruitful winter.

[summer blizzard]

I'm quite happy with this current high pressure.

The fact that it seems to be ever more south easterly orientated means that even if we never get it to Greenland we have a far better chance of importing cold air.

It should also be noted that Scandinavia and eastern Europe are about to be flooded with cold air which increases the chances of cooler surface air at least.

[keithlucky]

A lot of doom and gloom around on the model watching forum ,some snow reported in in the north and south netherlands(not forecasted) today with a windchill effect of -7,so snow isent to far away from UK.

Edited November 14, 2011 by keithlucky

[sebastiaan1973]

Although some big differences over here. This chart shows the max. temperatures today.

http://www.weerplaza.nl/actueel/extremen.asp

[Isolated Frost]

Although some big differences over here. This chart shows the max. temperatures today.

http://www.weerplaza...el/extremen.asp

Leeuwarden was reporting snow this morning!

[ZONE 51]

Snowmad79, on 14 November 2011 - 18:54 , said:

Ive been watching NOAA sst anomaly charts for the end of Sept/Oct and the latest available, the seas to our west should be cooling but are warming, a cool pool continues to develop way out accross the atlantic but what else I've noticed is that the seas around the southern tip of Greenland are indeed anomalously warm and continue to warm which is another positive point to note.

]

Good point! the temperatures in that area is what i watch especially, going to be an exciting winter! i see the present blocking as a building block, although not in its self as it is now(mild)nor the placement, but as an indication of what i expect is a blocking drier than average winter, we can have right high wrong place, i see these long periods of quite non change as a significant indication of what lies ahead, when we get the cold, we will be cold for a long time.

just copied pasted here as posted in another thread not meant to do that there.

Edited November 15, 2011 by ElectricSnowStorm

[len]

Currently positive snow-cover anomalies are mid/low-latitude. (Sourherly Jet?)

Large Asiatic anomaly.

http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2011&ui_day=320&ui_set=2

http://weather.rap.ucar.edu/surface/snowNESDISnh.gif

[BLAST FROM THE PAST]

Currently positive snow-cover anomalies are mid/low-latitude. (Sourherly Jet?)

Large Asiatic anomaly.

http://climate.rutge...ay=320&ui_set=2

http://weather.rap.u...nowNESDISnh.gif

Interesting research showing on the stratos thread re +ve Eurasia snow anomaly. This IMO will be part of the arctic Siberian HP we MAY see coming knocking on our door this winter.

I mentioned that a harsh NH winter is on the cards and its a matter of getting us in on it. Extra-ordinary cold going on right now with Alaska and Siberia. Max temps of -40 to -50 F are being recorded and its quite widespread.

BFTP

Edited November 19, 2011 by BLAST FROM THE PAST

[Jason T]

Interesting research showing on the stratos thread re +ve Eurasia snow anomaly. This IMO will be part of the arctic Siberian HP we MAY see coming knocking on our door this winter.

I mentioned that a harsh NH winter is on the cards and its a matter of getting us in on it. Extra-ordinary cold going on right now with Alaska and Siberia. Max temps of -40 to -50 F are being recorded and its quite widespread.

BFTP

Hi Fred, Do you think this winter will be an unexpected gate crasher regarding output that will just turn up, Also what are your thought's regarding winter 2011/12 as of current output. Ie more intense or less.

Manythanks.

SL

[BLAST FROM THE PAST]

Hi Fred, Do you think this winter will be an unexpected gate crasher regarding output that will just turn up, Also what are your thought's regarding winter 2011/12 as of current output. Ie more intense or less.

Manythanks.

SL

I think we'll get cold shots despite certain teleconnections saying otherwise or we'll get teleconnections that quickly slot into place. To be beat Dec2010? Hell of a thing so I won't say yes but I do think another 'extreme' period is in the offing this winter ie ice days with a good lowland covering of snow, this probably in New Year as I initially concurred with RJS LRF and the more I've had time to look at my method it has fallen into line with RJS pretty well solidly. I think RJS is glad I didn't join him because I would be pushing a Jan 85 or 87 event.......

BFTP

Edited November 22, 2011 by BLAST FROM THE PAST

[cooling climate]

I think we'll get cold shots despite certain teleconnections saying otherwise or we'll get teleconnections that quickly slot into place. To be beat Dec2010? Hell of a thing so I won't say yes but I do think another 'extreme' period is in the offing this winter ie ice days with a good lowland covering of snow, this probably in New Year as I initially concurred with RJS LRF and the more I've had time to look at my method it has fallen into line with RJS pretty well solidly. I think RJS is glad I didn't join him because I would be pushing a Jan 85 or 87 event.......

BFTP

Every time I read one of your posts I cringe. The younger ones on

this forum might believe your rubbish but I sure as hell DON'T.

[Backtrack]

I think we'll get cold shots despite certain teleconnections saying otherwise or we'll get teleconnections that quickly slot into place. To be beat Dec2010? Hell of a thing so I won't say yes but I do think another 'extreme' period is in the offing this winter ie ice days with a good lowland covering of snow, this probably in New Year as I initially concurred with RJS LRF and the more I've had time to look at my method it has fallen into line with RJS pretty well solidly. I think RJS is glad I didn't join him because I would be pushing a Jan 85 or 87 event.......

BFTP

Yes I share similar thoughts BFTP.

It could well be that January will be the big month this winter. I think the majority of our cold will be had in January with the CET well below average.

Edited November 23, 2011 by Backtrack

[Cecil Hogmanay Melchett]

What will be interesting is to see if one of the most startling statistics from the period we know as the m/era is tested.

Since 1987, whenever the December CET has exceeded 5C, as looks very likely given current output, the following Jan and Feb have been mild in 20 months out of 22 in the qualifying range. Even the ones that were not mild, could only be classes as average. They were February 1994 and January 2001.

Now of course, that period encompasses what we know as the m/era.What has happened in the last few winters has seen a marked change, so something to keep an eye on.

Thats quite a staggering statistic Ian but i would be a little reluctant to call an above average Dec at this juncture.Granted the 1st week at this time looks generally above the norm that still leaves 3 full weeks which to my mind are still very much up in the air.

[BLAST FROM THE PAST]

Can someone point me to where the first week of Dec looks likely at being above the norm? Just want to know where the 'probability' is coming from. It may be the case but plenty in model output to suggest more cooling as a possibilty [i don't think a freeze is coming iminently]

Intersting Ian and I think that stat will be fully tested as an aside. i think as you know that we have entered a new phase/cycle since Feb 2007 to reverse that. But interesting post and stats.

regards

BFTP

[Isolated Frost]

I agree with Ian, signs seem very zonal, and the odd northerly toppler will take a chunk out, but high winds and a increasing Tm influence will see a average-mild start.

[BLAST FROM THE PAST]

Well i think I've gone for a 5.4 c Dec temp. Re a large elephant, there's been a few mammoths removed over last 3 years Ian

BFTP

Edited December 10, 2011 by BLAST FROM THE PAST

[scotty_boy_winter]

Lmfao!!!! Great to see you move the goalposts now you've realised the first week in December won't be mild!!!

Very very clever Ian. Unfortunately you can't fool anyone and thats why people dismiss the majority of what you have to say. You said a mild first week. It's been cold. Now you say a mild last third. Even if it is mild you won't be right. If you were any good you would have got the first week right. Just keep saying mild, mild , mild and eventually you'll get one right (;

With a progressively milder last third of December now very much on the cards, a plus 5C Dec now looks likely.

Going forward I'm also seeing similarities between the fortcming Jan and Jan 1999, where the Stratospheric profile changed markedly but the PV persisted and HP to the NE could never develop as it may have done.

Either way, looking at my stats abov, a plus 5C December is a rather large elephant in the room when considering the subsequent Jan and Feb.

[feb1991blizzard]

What will be interesting is to see if one of the most startling statistics from the period we know as the m/era is tested.

Since 1987, whenever the December CET has exceeded 5C, as looks very likely given current output, the following Jan and Feb have been mild in 20 months out of 22 in the qualifying range. Even the ones that were not mild, could only be classes as average. They were February 1994 and January 2001.

Now of course, that period encompasses what we know as the m/era.What has happened in the last few winters has seen a marked change, so something to keep an eye on.

I wouldnt call feb 1994 average, i was in the midlands then and snow lay for 2 weeks out of the 4, we had a potent easterly which delivered ice days and heavy snow around the 11th or 12th i think and a reload the following week and it didnt warm up untill right at the end and as for your point about what has happened since 1987, well not a lot the last 3 years has been similar to winters post 1987,