Current state of La Nina

[North-Easterly Blast]

I have seen ENSO forecasts and most of them point towards La Nina conditions lasting throughout this year and remaining strong through the spring and weakening only slowly over the summer and into autumn. As there now seems little prospect of any significant northern blocking and any northerly or easterly outbreak this winter and that the rest of this winter will now be nothing other than average to mild, I think it is time to take our thoughts to what is this likely to mean for the spring, summer and autumn weather? The last time a La Nina lasted through the year was in 1999, and it remained no lower than -0.9 through the summer months before strengthening again for the following winter.

[kold weather]

I don't think there is as strong a link as strong la nina and winter for the rest of the seasons. In theory La Nina tends to promote scandinavian highs and also +ve NAO's, so I'm guessing SW would be quite dominant, varying from cyclonic to high pressure dominated, which could end up being rather warm when a cut-off high forms over Sandinavia.

[Weather-history]

Well the 4 la strong la ninas since 1950 led to generally dry springs but two were then followed by mediocre summers (1956, 1974) and two by superb summers (1976, 1989).

[Devon-Nelly]

Yes i think theres a very good chance it could be with us till mid Autumn, whether or not it'll persist through next winter or not who knows, i read on one of the sites that it has strengthend over the last month, to -2.0c.

Also i think the summer of 1975 was a La Nina summer and that was a very warm but quite thundery summer is that possible this year?

Edited February 15, 2008 by Devon-Nelly

[kold weather]

Yeah Mr.Data I don't think you can really make link outside winter, though there is more then 4 strong la nina's Mr.Data take a look at the NOAA CPC site that has a record of the SSTA in the ENSO zones, I counted 1950, 1974, 1976, 1989, 1999 and 2000 as being strong la nina winters:

http://www.cpc.noaa.gov/products/analysis_...ensoyears.shtml

[Weather-history]

Yeah Mr.Data I don't think you can really make link outside winter, though there is more then 4 strong la nina's Mr.Data take a look at the NOAA CPC site that has a record of the SSTA in the ENSO zones, I counted 1950, 1974, 1976, 1989, 1999 and 2000 as being strong la nina winters:

http://www.cpc.noaa.gov/products/analysis_...ensoyears.shtml

The reason why I said 4 was that I was using this consensus list. B)

http://ggweather.com/enso/years.htm

Has La nina strengthened again? Gavin P noted this

http://www.osdpd.noaa.gov/PSB/EPS/SST/data...t.2.14.2008.gif

[kold weather]

Ok fair enough so in other words they've taken 4 different methods rather then using one data source, I agree with them al as well, though I still question 55-56 though certainly December must have been strong alas though I'm nit-picking!

I should also say according to that website 2007-08 will NOT be a strong la nina, MEI isn't nearly low enough so far for them to be able to classify it as a strong la nina.

Who knows if its gotten stronger, its rare for La Ninas of any strength to peak later then Jan but then again this la nina was one of the latest to itself anyway so hardly surprising its turning out to be a late bloomer as they say!

[Jack Wales]

There is a fairly wide scatter regarding the enso status into summer with the favoured outcome being a neutral/weak La Nina scenario.

This is a good read from the noaa/cpc...

La Nina Diagnostic Discussion

[BrickFielder]

I think we are in a mature la nina stage which has a subtly different weather pattern as a result. El nino region one shows some warming now although it will not be untill autumn untill there is any subsidence in la nina across regions 3 and 4 if it occurs at all. The closest match I could detect in terms of timing of the onset of la nina and onset and ending of the easterly QBO is 1971. This gives a cold early spring followed by a warm and sunny late spring leading into a wet early summer and warm late summer and autumn.

96 and 66 had a different QBO phase but 1955 has some similarities which again gives a cool spring.

ENSO quick look

QBO Phases

Looks a bit like a north east atlantic trough for spring slowly migrating west to give a warm summer?

Effects of la nina and el nino on US weather

[johnholmes]

interesting thread and some good reading for me it seems with the various links, thanks folks, all helping an old meteorologists late understanding of this feature.

[Mr Maunder]

This is quite an interesting subject - and in time the outcome will become apparent.

I believe that a La Nina can be associated with the end of a Solar Cycle, which is where we are at the moment with the slow death of Cycle 23. It is interesting that the predicted end for this cycle continues to be moved further in to the future with some predictions now suggesting that the new Cycle 24 will not officially start until 2009. This would give us an extended period of low solar activity during the crossover between Cycles 23 and 24.

If this proves to be the case then this could be a factor in delivering an extended La Nina throughout 2008.

I've heard it suggested that a prolonged La Nina can also have an influence on sea temperatures beyond the Pacific. I've just been looking at the latest Unisys SST chart (I have not looked for a while) and was surprised to see just how relatively "cool" the global oceans are. Even the North Atlantic has lost many of the more positive anomalies that were present for much of last year.

The question raised here is that if La Nina does prove to have legs and does impact SSTs does this have any potential impact for the UK when it comes to Winter 2009?

MM

[sundog]

I think this is an interesting thread. Its strange i was just thinking today to ask what would the state of la nina be for the rest of the year. If la nina was to start weaking say in a few months time and was weak in time for next winter,would that mean that next winter could be a decent one?

[North-Easterly Blast]

I think this is an interesting thread. Its strange i was just thinking today to ask what would the state of la nina be for the rest of the year. If la nina was to start weaking say in a few months time and was weak in time for next winter,would that mean that next winter could be a decent one?

There is evidence to suggest that weak to moderate La Ninas encourage cold spells, as can be seen in a number of winters of the past, winters 1950-51, 1954-55, 1955-56, 1964-65, 1967-68, 1970-71, 1974-75, 1984-85, 1985-86, 1995-96, 2000-01, and 2005-06 all had a weak to moderate La Nina in place, and of all these eight of them were rather cold or cold winters with a number of or notable cold spells, and even 2000-01 and 2005-06 were at least reasonably average and two of the better winters in recent years. The only winter that was awful was 1974-75, so it is good evidence that a weak La Nina can be a good signal for colder conditions in winter in the UK. Another one is that the very severe winter of 1962-63 was actually a very weak La Nina winter.

However, like this year, strong La Nina winters have often favoured largely mild winters for the UK with spells of northern blocking and north or east outbreaks in short supply, (although rarely exceptionally mild like 1988-89) and this winter has largely gone the way of our last strong La Nina winter in 1999-2000, which was also mild overall with no significant spells of northern blocking and mostly snowless for most of the UK.

If La Nina does weaken through the year and does not re-stregthen again and also if the SST pattern in the North Atlantic changes to more of a mix of cold and warm pools, then next winter could well be much better than this year, but given the almost complete lack of UK wide cold outbreaks since the 1995-96 winter, and the way most winters of the last 20 years have been, I am now fearing that a winter like 2000-01 or 2005-06 is the modern version of cold winters like 1995-96 or the mid 1980s.

Here's to the sort of zonality that we want:

www.wetterzentrale.de/archive/ra/1984/Rrea00119840116.gif

www.wetterzentrale.de/archive/ra/1984/Rrea00119840124.gif

In the orientation above zonality does or has delivered cold and snow, and overall a classic cold month in Scotland.

Never this sort

www.wetterzentrale.de/archive/ra/2008/Rrea00120080125.gif

[stormchaser1]

Afternoon everyone

After looking through some previous posts, it seems that this years La Ninas event is quite a strong event, ive found some data, suggesting that there was also strong La Nina events in 1988- 1989/ also there was a even stronger event between 1998- 2001/ yep a 3 year La Nina, ive looked at some CET readings from these years and each year there has been a strong LA Nin event the ANNUAL CET has been in the 10s

1989= 10.5

1990= 1062c

1998= 10.31c

1999= 10.61c

2000= 10.30c

January 1989= 6.1c

January 1990= 6.5c

January 1998= 5.2c

january 1999= 5.5c

If this is a strong LA NINA which it looks lit it is , ive got a funny feeling , this year 2008 we could see a Annual mean temp

anywhere between 10.0c and 10.60c

Could we be in for another LA NINA event lasting for 3 years i wonder !!!!!

Nigel

[damianslaw]

Afternoon everyone

After looking through some previous posts, it seems that this years La Ninas event is quite a strong event, ive found some data, suggesting that there was also strong La Nina events in 1988- 1989/ also there was a even stronger event between 1998- 2001/ yep a 3 year La Nina, ive looked at some CET readings from these years and each year there has been a strong LA Nin event the ANNUAL CET has been in the 10s

1989= 10.5

1990= 1062c

1998= 10.31c

1999= 10.61c

2000= 10.30c

January 1989= 6.1c

January 1990= 6.5c

January 1998= 5.2c

january 1999= 5.5c

If this is a strong LA NINA which it looks lit it is , ive got a funny feeling , this year 2008 we could see a Annual mean temp

anywhere between 10.0c and 10.60c

Could we be in for another LA NINA event lasting for 3 years i wonder !!!!!

Nigel

I hope we dont have a 3 year strong la nina as this would suggest another 2 winters like we have just had this year - please I couldn't take it.. 98, 99 and 00 delivered too preety poor by recent standards summers so in this respect aswell I don't want strong la nina - go away please..

[stormchaser1]

http://www.cpc.noaa.gov/products/analysis_...ensoyears.shtml

El NiNO and LA NINA events,

nigel

[shuggee]

As I've said before it's hats of to our very own UK Metoffice for going out on a limb in early autumn and calling a strong La Nina when all other Met Centres were predicting very weak/weak

[Snowyowl9]

So the last la nina winter like this year was 1999-2000

November gave no snow different to this one.

Thought there was a similar pattern to that winter at times there was a cold snap or 2 in december then.

This being the coldest night/day under HP and a max which was colder than the coldest day this winter by 1c.

http://www.wetterzentrale.de/archive/ra/19...00119991220.gif

Had more snow that month also.

Got an odd snow flurry in January literally :lol:

http://www.wetterzentrale.de/archive/2000/...00120000124.png

The best feb gave in terms of frost at -4c old gauge, infact that was a very poor month overall did get odd days of wintry showers from the atlantic though like this winter infact

http://www.wetterzentrale.de/archive/2000/...00120000220.png

The first half of March only gave 1 frost and a hail shower

But winter came in April big time with heavy snow and blizzards at 6 inches during this day to start with.

http://www.wetterzentrale.de/archive/ra/20...00120000403.gif

April 1989 was another when winter arrived late with cold east winds and snow showers less snow to April 2000 though.

Edited February 16, 2008 by Snowyowl9

[Snowyowl9]

I should of put the coldest day during that winter(1999-2000) in december was only 1 ice day all winter was 0.5c colder to the 3 ice days this winter here also 3 in december and one in January, now that looks better.

Edited February 16, 2008 by Snowyowl9

[damianslaw]

The reference relating to what occured in both 1989 and 2000 both strong la nina years which gave snowfall in april should serve as a strong reminder that snow should never be ruled out until June sets in (admittedly chances in May dwindle markedly). Those who are saying thats it if for this year in terms of snow I personally feel are being exceptionally naive.

A cold scenario can develop at anytime during March and April even on the back of prolonged mildness i.e. 1989 and 2000 capable of delivering snow. We are entering the period of the year when the atlantic is traditionally at its quietest and when we see easterlies and northerlies reach their yearly maxim (late feb- through to May), expect the unexpected...

[johnholmes]

very true D

[damianslaw]

Just to further add to my last point, April 1998 delivered a marked spell of wintry weather around easter time (for some it was the snowiest perios of the winter season in what was the middle of spring!) coming on the back of another relatively snowless and mild winter, likewise April 1999 to a lesser extent. These too were strong la nina years - mmm seems to be a pattern there...

[sundog]

Just to further add to my last point, April 1998 delivered a marked spell of wintry weather around easter time (for some it was the snowiest perios of the winter season in what was the middle of spring!) coming on the back of another relatively snowless and mild winter, likewise April 1999 to a lesser extent. These too were strong la nina years - mmm seems to be a pattern there...

Yes i remember the cold snap in april 1998. I think it was around april 14th or so we had about 2 inches of snow that night,it was strange waking up to a snowy scene the next morning in the middle of april. I remember for a laugh one of the radio stations here played one or two xmas songs and all. Once the april sun got at the snow that was all she wrote though, it was all gone by lunchtime but it was memorable. I think the snow came from a polar low although i may be wrong about that bit.

[sundog]

Well looking at the archive i dont think it was from apolar low ,but anyway. Sorry they are clearly the wrong charts havent tried this before dont know were the hell they came from :lol:

Edited February 17, 2008 by sundog

[BLAST FROM THE PAST]

I remember in autumn 2006 talk was of how long the then El Nino would last ie into summer 2007. I stated that [based on Landscheidts research] the El Nino would be dead by April 2007 possibly as early as Feb 2007. The reason behind this is that in Feb 2007 the perturbation cycle started where we are now in a phase of about 35 years where La Nina will not only be dominant but some strong and prolonged events will occur. After 12months this is in line with the cycle [early days yes] but this will accompany a deep Gleissberg minima peaking on 25 around 2030. Mr Maunder has touched on it, solar cycle 24 should have started 14 months ago but it still hasn't. Astrophysicists stated that a deep minima approaches and that cycle 24 will be much quieter than expected by NASA or NOAA. Well it looks like the Astros are correct and indeed it could be even quieter still.

I personally think that winter for the UK won't be changed until 2010 onwards at least as I agree with what RJS has said that there has been a climate shift possibly directly linked to the big movement of the NMP which continues to move which in turn is linked to the solar magnetic field.

Re this year it won't be a scorcher and agree that cold/wet early spring then a warm up then a poor start to summer then better conditions later on....but no heat wave

BFTP

Edited February 17, 2008 by BLAST FROM THE PAST