Autumn 2011

[SP1986]

Obviously it will change, but I don't think it's automatically a guaranteed cold winter like some seem to be suggesting.

I saw before someone suggesting a -NAO/+AO combination would be ideal setup - I assume for cold? I'm not sure I agree with this, that pattern combination could upset the balance that allows a cold setup.

The amount of variables that go into allowing a setup to well, setup must be so much so that, perhaps soberingly, this winter could go either way, regardless of theories that low solar activity may cause it or that we are due for one.. imagine if weather worked that way, we'd have ideal weather conditions all the time.

[Geordiesnow]

If this current pattern doesn't change. We will be in for a VERY mild winter indeed. Not good. I hope it changes, but I've been hoping it will change all Summer, it just isn't happening it seems.

Dearie me its starting already and we are only into Autumn FGS! Keep the weather pattern as it is, I love wet and windy weather at this time of year, Scandi high's and whatever can wait until January and February. If I want any cold shot, then let it be a Northerly via a Greenland high but its going to be a long winter if posts like the one I quoted is starting already.

[cooling climate]

We have to remember though, that, that was 3 years ago now. The models have been updated, no doubt tweaked and improved since then. They called last years cold winter generally correct in October I believe, I don't have a link to the archived charts and I'm going on memory, so don't hold me to that.

The winter of 2011/2012 was NOT a cold winter. December 2011 was a

very cold wintry month in many areas but one month does not make up

a winter.

[Don]

The winter of 2011/2012 was NOT a cold winter. December 2011 was a

very cold wintry month in many areas but one month does not make up

a winter.

I think you mean Winter 2010/2011 unless I've gone mad! Winter 2010/11 was still cold overall on paper, although that was totally down to the bitter cold December with January being only a little way below average and February very mild. Just goes to show how one month can mask the reality of a season. Last Winter was like a reversed 1985/86 with that one having a very mild December followed by a slightly below January and bitter February.

Edited September 8, 2011 by Don

[Met4Cast]

The winter of 2011/2012 was NOT a cold winter. December 2011 was a

very cold wintry month in many areas but one month does not make up

a winter.

Yes I understand that.

But the overal temperature for the winter 2010/11 came in below average, and the CFS was calling for below average temperatures.

[Robbie Garrett]

Why dont we just change the topic title to Winter 2011/12 as it's a useful thread.

[I remember Atlantic 252]

The winter of 2011/2012 was NOT a cold winter. December 2011 was a

very cold wintry month in many areas but one month does not make up

a winter.

would be fantastic if dec 2011 is cold,

[Optimus Prime]

Statistically 2010/2011 was cold but in context the winter had an equal number of cold and mild days. But the cold so extreme during December it skewed the figure, just like 1985/1986.

It averaged 3.1c overall. 1.8c below the very mild 1988 - 2008 period which averaged 4.9c. Combining January and February 2011 CET would in this case produce a near typical winter temperature experienced during the 1988 - 2008 period. Combining the UK average temperature of January and February 2011 would actually come in very slightly below the 1988 - 2008 data set despite such a mild February (January 2011 was actually a severe winter month for Northern Ireland coming in below 3.0c skewing the UK figure further)

Edited September 8, 2011 by Optimus Prime

[North-Easterly Blast]

Statistically 2010/2011 was cold but in context the winter had an equal number of cold and mild days. But the cold so extreme during December it skewed the figure, just like 1985/1986.

It averaged 3.1c overall. 1.8c below the very mild 1988 - 2008 period which averaged 4.9c. Combining January and February 2011 CET would in this case produce a near typical winter temperature experienced during the 1988 - 2008 period. Combining the UK average temperature of January and February 2011 would actually come in very slightly below the 1988 - 2008 data set despite such a mild February (January 2011 was actually a severe winter month for Northern Ireland coming in below 3.0c skewing the UK figure further)

Winter 2010-11 was only below average due to such extreme cold during December, although the rest of the winter was certainly nothing special and February was well above average. Take the period 1st to 27th December out of the equation and winter 2010-11 has a CET of 5.0*C, not the 3.1 that it ended up. All in all, post Xmas, winter 2010-11 can be seen as a typical winter of the mild 1988-2008 period. This plainly describes that winter 2010-11 was purely an example of a winter starting with an extreme cold spell only to deteriorate into nothing, and the rest of the winter was not special - it isn't an example of a winter being cold overall when the post Xmas part of the winter delivered next to nothing. For a winter being cold overall, 2009-10 was, and winter 2008-09 was reasonable at least up to mid Feb.

Not sure about 1985-86, there was some cold weather before the February. It was very mild up to Xmas 1985 but in the final week of Dec 1985 a cold spell developed, and it was mostly cold up until Jan 10th 1986 with some snow early Jan. It then turned milder for a couple of weeks before becoming cold again in the last week of Jan. Certainly winter 1985-86 was cold overall at least from Xmas 1985 to the end of Feb / early March.

Edited September 8, 2011 by North-Easterly Blast

[Harry444]

Winter 2010-11 was only below average due to such extreme cold during December, although the rest of the winter was certainly nothing special and February was well above average. Take the period 1st to 27th December out of the equation and winter 2010-11 has a CET of 5.0*C, not the 3.1 that it ended up. All in all, post Xmas, winter 2010-11 can be seen as a typical winter of the mild 1988-2008 period. This plainly describes that winter 2010-11 was purely an example of a winter starting with an extreme cold spell only to deteriorate into nothing, and the rest of the winter was not special - it isn't an example of a winter being cold overall when the post Xmas part of the winter delivered next to nothing. For a winter being cold overall, 2009-10 was, and winter 2008-09 was reasonable at least up to mid Feb.

Yepp, well said. 2008-2009 was my favorite winter because here in the north west of England we got a very cold spell at the very start of December too. And also I suppose when you say 'up until Mid Feb', there was only two weeks of Winter in theory left.

[Optimus Prime]

Well DJF are categorised, officially as being the winter season, and that's how it's statistically calculated regardless of what singular months happen to show. The mean UK temperature was still well below normal.

Even using the winter 1944/1945 as an example. December and January averaged 3.6c and 0.4c respectively. February came along and averaged an extremely mild 7.1c. Despite the mild February it still averaged a chilly 3.7c and I would class that as a cold winter because of the extreme January.

[North-Easterly Blast]

I think you mean Winter 2010/2011 unless I've gone mad! Winter 2010/11 was still cold overall on paper, although that was totally down to the bitter cold December with January being only a little way below average and February very mild. Just goes to show how one month can mask the reality of a season. Last Winter was like a reversed 1985/86 with that one having a very mild December followed by a slightly below January and bitter February.

Dec 1985 may have been a very mild month but the mild ended over Xmas 1985 and then a cold spell set in, and lasted until Jan 10th 1986, and then returned late Jan.

In fact, take out the period 1st - 26th Dec 1985 and then the remaining 64 days of winter 1985-86 from Dec 27th has a CET of 1.1*C - so winter 1985-86 was "severe" overall after the Xmas period of 1985. Winter 1985-86 was sort of a severe winter that took a bit longer to get going - although on paper the winter quarter wasn't severe overall with a CET of 2.9. On top of that, Nov 1985 was also a particularly cold Nov at 4.1 CET. 1985-86 was basically a very cold, extended winter with a three week very mild spell in the December.

Certainly a very cold pre-Xmas period like in 2010 with the rest of the winter delivering next to nothing doesen't make a cold winter overall.

Edited September 8, 2011 by North-Easterly Blast

[Gavin P]

If this current pattern doesn't change. We will be in for a VERY mild winter indeed. Not good. I hope it changes, but I've been hoping it will change all Summer, it just isn't happening it seems.

Can anyone tell me if there is any change in the 500mb charts?

Also, I think it's time we started a thread for Winter. That's all most people are interested in, plus it is now beyond summer.

Well given this northerly displaced Azores High has been a semi-permanant feature since May, I think its very unlikely to last in its present form all the way through autumn and winter. That would be like 9 months for one singularity. Would be very unusual to say the least.

No, the synoptic will change over the next few months - For good or ill...

Edited September 8, 2011 by Gavin P

[Aaron]

The winter of 2011/2012 was NOT a cold winter. December 2011 was a

very cold wintry month in many areas but one month does not make up

a winter.

Of course it was a cold winter. The latter half might have been milder but overall it was cold and this is fact not opinion so is not up for debate.

[cooling climate]

Of course it was a cold winter. The latter half might have been milder but overall it was cold and this is fact not opinion so is not up for debate.

I am not debating it. There is nothing to debate, winter 2010/2011 was NOT a cold

winter end of.

[Radiating Dendrite]

Of course it was a cold winter. The latter half might have been milder but overall it was cold and this is fact not opinion so is not up for debate.

Completely agree.

Overall it was average, containing a very cold month, an average month and a warm month.

You can not categorise a season based on one month as there three months that need to be considered.

An accurate description of last winter would be "the winter was around average statistically, but contained the 2nd coldest December on record, this being balanced out by a particularly warm february".

Edited September 9, 2011 by Radiating Dendrite

[kold weather]

Given we had one of the coldest Decembers ever and a 45-60 day period where we were pretty much averaging around 0C...I'll call it a cold winter.

Sure it may have been a lopsided...but the potentcy of that cold spell was so severe and so long I think very few people other then yourself would descirbe it as not a cold winter.

We had one very severe cold month (though truth be told the 20th november to the 10th Jan was very severe) a BELOW average month in Jan (below 61-90 average as well...so a true below average mont and quite a long way below the 81-10 average) and a very mild Feb.

Last winter had a CET of 3.13C, thats nearly 1C below the 61-90 average and IF you extended that out to the 20th of November, you would be over 1C below that average, which is cold. Nearly 1.5C below the 81-10 average.

Sorry...thats cold no matter how you try and cut it, even if most of it did come in one exceptional and record breaking prolonged spell.

[Isolated Frost]

One of the posts says if you take out the period 1-27 Dec it was not cold - of course not. Why don't we take out February? Or January? Fact is, December IS winter and contributes to the CET. If we are talking about Winter here, then you have to include December. Simple.

[Geordiesnow]

One of the posts says if you take out the period 1-27 Dec it was not cold - of course not. Why don't we take out February? Or January? Fact is, December IS winter and contributes to the CET. If we are talking about Winter here, then you have to include December. Simple.

Agreed but I think its the fact that whilst January was cold, the set ups that came with it was not all that snowy and I think this is also clouding people judgements on what was a cold winter overall.

I mean, maybe people won't remember the winter as a whole as being a cold one but people should not forget the months that was cold, eg December 2010, February 1991 January 1987 all come to mind.

Its interesting that February 2011 was claimed to be avery mild month yet I look at the past charts, it seems to me it was below average for the majority of the month apart from the very mild spell at the end of the month and the mild spell around the 6th-8th in Southern areas. February looked an average to just below one across Scotland for example with any cold spells coming from the WNW'ly direction.

[kold weather]

To be fair at least in the CET zone Feb was very mild but yeah I find it an odd logic that just because one month was nearly record breakingly cold and the other two were either just below or way above that somehow it ends up as being an average winter...

Anyway I fear we are straying from the point of the threat, this talk can be relocated to the winter thread.

[Weather-history]

The wonders of stats, Was winter 2010-11 cold?

Well lets look at this: Was autumn 2009 wet? The overall figure says yes but I could say, take out the November total and October was close to average and September was below average. So was autumn 2009 wet, the answer is still yes because rainfall totals are cumulative in the same way sunshine totals are.

So what about winter 2010-11 was it cold? Temperatures are not cumulative but averaged. Well the nett result is cold ergo winter 2010-11 was nett cold. And if we are going to cherrypick if I add in the last week of November and take out the last 7 days of February, I would come up with a CET of 2.5 (incidentally the CET for November-January was 2.7C)

I don't see the difference between calling winter 2010-2011: cold and calling the year 2006: warm.

The first three months of 2006 were not warm but are people questioning 2006 as a warm year as they with winter 2010-2011?

Edited September 9, 2011 by Mr_Data

[sebastiaan1973]

Well we can take in our winter predictions one factor for 'sure'. According to NOAA, La Nina is back.

Synopsis: La Niña conditions have returned and are expected to gradually strengthen and continue into the Northern Hemisphere winter 2011-12.

La Niña conditions returned in August 2011 due to the strengthening of negative sea surface temperature (SST) anomalies across the eastern half of the equatorial Pacific Ocean (Fig. 1). With the exception of the far westernmost Niño-4 region, all of the latest weekly Niño index values were –0.5oC or less (Fig. 2). Also supporting the return of La Niña conditions was the strengthening of the below-average subsurface oceanic heat content anomaly (average temperature anomalies in the upper 300m of the ocean, Fig. 3), in response to increased upwelling and further shoaling of the thermocline across the eastern Pacific Ocean (Fig. 4). The atmospheric circulation over the tropical Pacific continued to exhibit La Niña characteristics, but remained weaker and less canonical than the wintertime atmospheric patterns. For example, convection continued to be suppressed near the Date Line, but remained south of the equator, while convection was only weakly enhanced near Papua New Guinea (Fig. 5). In addition, anomalous low-level easterly and upper-level westerly winds persisted over the central tropical Pacific. Collectively, these oceanic and atmospheric patterns reflect the return of La Niña conditions.

Over the last several months many models have predicted increasingly negative SST anomalies in the Nino-3.4 region during the upcoming Northern Hemisphere fall and winter. However, the majority of models continue to predict ENSO-neutral conditions for this period (Fig. 6). The NCEP Climate Forecast System (CFS) has performed quite well over the past several months (Fig. 7) capturing the recent decrease in SST anomalies. The better model performance, combined with the historical tendency for significant La Niña episodes (as in 2010-11) to be followed by relatively weaker La Niña episodes, leads to increased confidence that La Niña will persist into the winter. While it is not yet clear what the ultimate strength of this La Niña will be, La Niña conditions have returned and are expected to gradually strengthen and continue into the Northern Hemisphere winter 2011-12.

http://www.noaanews.noaa.gov/stories2011/20110908_lanina.html & http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

[cyclonic happiness]

The thing that maters WAY beyond all the weird statistics, is peoples viewpoint and judging by that alone, last winter WAS a cold winter, as were the two before.

You ask any little old lady at a bus stop or lay person in a supermarket and they'll all tell you last winter was a cold one and that we seem to be in a pattern of colder winters now.

Now for some reason I feel more inclined towards what they are telling me the winter will do, and less inclined to listen to the 'experts' and the lay people are telling me that we are in for another very cold winter.

I'm sure all the pedants will be popping up now telling me how wrong I am

[I remember Atlantic 252]

I would class last winter as cold, to me February is Spring, so late Nov was cold, virtually all of Dec, and 1st 9 days of Jan (for southern UK) any cold fan even in southern UK like me should be happy with it

Northern UK and Scotland winter even extended in to Feb

[ZONE 51]

what do others think about october? all chat (and very interesting)about the winter(s) but nothing on autumn!