Summer Discussion!

[summer blizzard]

Firstly, i will start by saying that i created this thread to discuss the upcoming summer prospects, so don't feel pressured to making a forecast because at this early stage, it would most likely be wrong, this is to discuss the variables ect...

That aside, i am personally a supporter of teleconnections, and as such, my first post in this thread will discuss this...

IMO, there are three main variables (leading modes), which make up a large percentage of a succesful forecast, these being..

1) ENSO state

2) QBO state

3) AO state

It is my personally belief that these three teleconnections are invariably linked.

In regards to the ENSO state, we are currently in moderate La Nina conditions. La Nina is correlated to lower than average angular mommentum (GLAAM), which essentially means that when La Nina conditions are present, there is typically a slow moving weather pattern. As well as the actual state of La Nina, it is my belief that whether La Nina is weakening or strengthening is also important, because La Nina is currently weakening, this teleconnects to a progressively less slow moving pattern, but a anticyclonic pattern, which in summer is correlated to above average temperatures.

In regards to the QBO state, during March, the QBO switched modes, and is now in a westerly mode, which is correlated to lower than average pressure in the Tropics, and mid-lattitude High pressure belts as a response, as well as stronger statospheric winds around the pole (stronger Polar Vortex), it is my belief that with a strengthening westerly QBO during the summer, this will correlate to a higher chance of mid-lattitude blocking.

In regards to the AO state, it is essentially a measure of the temperature in the statosphere at high lattitudes, and we are currently seeing a stratospheric cooling event, which is correlated to lower than average pressure over the poles (stronger Polar Vortex), the AO is quite strongly correlated to the NAO, meaning that when the AO is positive, the Azores High and Icelandic Lows are stronger, whereas it is visa versa during a neagative AO.

Tying these teleconnections together, it is my belief that the UK will see higher than average temperatures, and lower than average rainfall this summer. In regards to the first half of this summer, i expect a higher incidence of northerlies/easterlies than average, though i also expect the first half of summer to be the driest relative to average, to my knowledge, high pressure to the north of the British Isles would also lead to above average sunshine. In regards to the second half of sunshine, i expect this to feature a more orginised Polar Vortex, however with a signal for continued anticyclonicy, this should lead to higher pressure to the south east of the UK, with a greater amplitude of southerlies/westerlies relative to average, meaning that relative to average, i expect the second half of summer 2008 to be the hottest, though it is likely to be wetter and duller than the first half relative to average, however i do expect a continuation of below average rainfall and around average sunshine.

[azores92]

can i add my opinions. a weakening la nina doesn't always mean anticyclonic weather in summer, it means changeable weather, and a weaker cell, which means low pressure can quite easily dominate the summer weather as much as a high would. however, whatever happens the strength of these "systems" is increased due to a positive NAO meaning that more intense rainfall events are likely. so as much as i hate to say it, i think this summer could bring above average precipitation, but i think temperatures are likely to be above average, due to the southerly airflow.

Edited April 12, 2008 by azores92

[damianslaw]

can i add my opinions. a weakening la nina doesn't always mean anticyclonic weather in summer, it means changeable weather, and a weaker cell, which means low pressure can quite easily dominate the summer weather as much as a high would. however, whatever happens the strength of these "systems" is increased due to a positive NAO meaning that more intense rainfall events are likely. so as much as i hate to say it, i think this summer could bring above average precipitation, but i think temperatures are likely to be above average, due to the southerly airflow.

Mmm don't like the sound of a wet southerly summer i.e. a humid one yuk yuk and more yuk

[Timmead]

All we can accurately say at the moment is that temperatures will almost certainly be above "average"; predictions about rainfall are any one's guess really, though amounts will probably be close to typical values.

[The PIT]

Too early to say. Last year I said dry and hot and look what happened. Someone even managed to find my orginal post and post in the middle of July. :lol:

Last years crap summer was blamed on La Nina. Even though there wasn't one at the time. Experts hang you head in shame. So if last years summer was crap due to neutral conditions this years should be wetter. Not serious by the way.

[Iceni]

Too early to say. Last year I said dry and hot and look what happened. Someone even managed to find my orginal post and post in the middle of July. :lol:

Last years crap summer was blamed on La Nina. Even though there wasn't one at the time. Experts hang you head in shame. So if last years summer was crap due to neutral conditions this years should be wetter. Not serious by the way.

I don't really care how much it rains or how hot and sunny it gets. What I do wish is that it would be more changeable. The last few summers seemed to have been weeks and weeks of endless rain or weeks of relentless sun and drought... either way, it's desparately hard work trying to keep a garden looking its best.

Is this what is referred to as 'zonality'? I'd prefer mini heatwaves followed by a few days rain and so on.

[Thundery wintry showers]

A warm but wet southerly summer might not necessarily be that unpleasant, depending on the circumstances. I remember June 2003, for example, being warm and sunny from a setup like that, but wet due to a few intense downpours, and recall some decent T-storms thrown in as well.

On the other hand, I remember June 2002 having a lot of dull warm muggy SW'ly winds, and I think it was the dullest since 1998, the average maximum was a pretty average 17C yet the average minimum temp was probably the highest since 1982. So I suspect that kind of setup could go either way.

[Bottesford]

Hopefully hot & sunny May & June, nice in July (I'm away for first two weeks so don't care so much!) then thundery in August - that'd be grand! I suspect it won't pan out like that and that we'll get something more average this year. So long as it isn't like last years cack...

Summer is def the season I care the most about the weather as it has a much greater effect on day to day life as you (hopefully) spend much more time outdoors than any other time of year. Shall be watching all forecasts with interest!

[J07]

I don't really care how much it rains or how hot and sunny it gets. What I do wish is that it would be more changeable. The last few summers seemed to have been weeks and weeks of endless rain or weeks of relentless sun and drought... either way, it's desparately hard work trying to keep a garden looking its best.

Is this what is referred to as 'zonality'? I'd prefer mini heatwaves followed by a few days rain and so on.

Zonal means east-west motion as opposed to meridional which is north-south motion. I'm not entirely sure what people mean when they say "zonality" or whether there even is a precise definition.

I think gardening in summer should be a challenge. Summer rain I find is quite often a bit of a let down with lots of it going to waste. It'll also never please everyone. In summer you're going to need several days of fairly continuous rain coming down so that it does to good use for flowers, however, if you're someone that is trying to ripen tomatoes this is pretty bad news.

[Thundery wintry showers]

I think when people talk of "zonality" they mean a fast-flowing Atlantic with depressions moving swiftly west to east, especially if they're tracking over or to the north of Scotland giving much or all of mainland Britain westerly winds as well as frequent west-east tracking lows.

Thus, re. the Junes I mentioned, June 2002 would classify as a zonal month because it had a constant stream of depressions moving SW-NE to the north, while June 2003 wouldn't, at least not to the same extent, because it often had blocking highs to the east and slow-moving lows in the Atlantic throwing bands of showers and thunderstorms north-eastwards across Britain from time to time.

A "zonal" summer month will usually be cool, cloudy and wet, because the fast-moving depressions bring bands of frontal rain eastwards across the country, which suppress temperatures and bring a lot of cloud generally. However, if there are a lot of SW'ly warm sectors around it may be warm by night (e.g. June 2002).

[Weather-history]

Can this be the summer that breaks this run?

Summers ending in "8"

1888 CET: 13.7 Rain: 317mm

1898 CET: 15.1 Rain: 166mm

1908 CET: 14.9 Rain: 216mm

1918 CET: 14.9 Rain: 204mm

1928 CET: 14.8 Rain: 253mm

1938 CET: 15.3 Rain: 226mm

1948 CET: 14.8 Rain: 259mm

1958 CET: 15.3 Rain: 310mm

1968 CET: 15.1 Rain: 274mm

1978 CET: 14.5 Rain: 210mm

1988 CET: 14.8 Rain: 268mm

1998 CET: 15.2 Rain: 230mm

2008 ?

CET average: 14.9 Rainfall: 244mm

Is Summer 2008 going to break this odd run or is it going to continue?

The CET average and rainfall averages for summers ending in other numbers for that period of 1880-2007

0 CET average: 15.3 Rainfall: 235.5mm

1 CET average: 15.4 Rainfall: 218.4mm

2 CET average: 14.9 Rainfall: 238mm

3 CET average: 15.6 Rainfall: 200.5mm

4 CET average: 15.4 Rainfall: 218.2mm

5 CET average: 15.7 Rainfall: 194.7mm

6 CET average: 15.5 Rainfall: 211.1mm

7 CET average: 15.4 Rainfall: 213.8mm

8 CET average: 14.9 Rainfall: 244mm

9 CET average: 15.6 Rainfall: 186.9mm

The best summers in that period tended to end in "3" "5" and "9" whilst the poorest tended to end in "2" and "8"

Another interesting fact about summers ending "8" is that there is only one July in that period (1888-1998) actually got above a CET of 16.0 (1928 with 16.1)

Using England and Wales sunshine figures

The sunshine average for summers ending in "5": 591.3hrs

Sunshine average for summers ending in "8": 472.3hrs that compares to summers ending in "2" with an average of 513.4hrs

Taking this into account then the summers ending in "8" have been the poorest overall

Manchester Summer Index average

For summers ending in "8": 193

For summers ending in "5": 233

[mushymanrob]

Can this be the summer that breaks this run?

Summers ending in "8"

1888 CET: 13.7 Rain: 317mm

1898 CET: 15.1 Rain: 166mm

1908 CET: 14.9 Rain: 216mm

1918 CET: 14.9 Rain: 204mm

1928 CET: 14.8 Rain: 253mm

1938 CET: 15.3 Rain: 226mm

1948 CET: 14.8 Rain: 259mm

1958 CET: 15.3 Rain: 310mm

1968 CET: 15.1 Rain: 274mm

1978 CET: 14.5 Rain: 210mm

1988 CET: 14.8 Rain: 268mm

1998 CET: 15.2 Rain: 230mm

2008 ?

CET average: 14.9 Rainfall: 244mm

Is Summer 2008 going to break this odd run or is it going to continue?

The CET average and rainfall averages for summers ending in other numbers for that period of 1880-2007

0 CET average: 15.3 Rainfall: 235.5mm

1 CET average: 15.4 Rainfall: 218.4mm

2 CET average: 14.9 Rainfall: 238mm

3 CET average: 15.6 Rainfall: 200.5mm

4 CET average: 15.4 Rainfall: 218.2mm

5 CET average: 15.7 Rainfall: 194.7mm

6 CET average: 15.5 Rainfall: 211.1mm

7 CET average: 15.4 Rainfall: 213.8mm

8 CET average: 14.9 Rainfall: 244mm

9 CET average: 15.6 Rainfall: 186.9mm

The best summers in that period tended to end in "3" "5" and "9" whilst the poorest tended to end in "2" and "8"

Another interesting fact about summers ending "8" is that there is only one July in that period (1888-1998) actually got above a CET of 16.0 (1928 with 16.1)

Using England and Wales sunshine figures

The sunshine average for summers ending in "5": 591.3hrs

Sunshine average for summers ending in "8": 472.3hrs that compares to summers ending in "2" with an average of 513.4hrs

Taking this into account then the summers ending in "8" have been the poorest overall

Manchester Summer Index average

For summers ending in "8": 193

For summers ending in "5": 233

thats interesting.... but what about last summer '7'.. obviously the year number has no bearing on the weather, but this sort of random statistics dont half prove that you can stoke up 'spiritual' things out of nothing!

[I remember Atlantic 252]

summer this year id guess wet maybe as bad as last year, wettest spell of the summer will be 23rd June- 6th July, clubland tv playing 'summer rain' right now gonna see a lot of it lol

[Timmead]

Can this be the summer that breaks this run?

Summers ending in "8"

1888 CET: 13.7 Rain: 317mm

1898 CET: 15.1 Rain: 166mm

1908 CET: 14.9 Rain: 216mm

1918 CET: 14.9 Rain: 204mm

1928 CET: 14.8 Rain: 253mm

1938 CET: 15.3 Rain: 226mm

1948 CET: 14.8 Rain: 259mm

1958 CET: 15.3 Rain: 310mm

1968 CET: 15.1 Rain: 274mm

1978 CET: 14.5 Rain: 210mm

1988 CET: 14.8 Rain: 268mm

1998 CET: 15.2 Rain: 230mm

2008 ?

CET average: 14.9 Rainfall: 244mm

Is Summer 2008 going to break this odd run or is it going to continue?

The CET average and rainfall averages for summers ending in other numbers for that period of 1880-2007

0 CET average: 15.3 Rainfall: 235.5mm

1 CET average: 15.4 Rainfall: 218.4mm

2 CET average: 14.9 Rainfall: 238mm

3 CET average: 15.6 Rainfall: 200.5mm

4 CET average: 15.4 Rainfall: 218.2mm

5 CET average: 15.7 Rainfall: 194.7mm

6 CET average: 15.5 Rainfall: 211.1mm

7 CET average: 15.4 Rainfall: 213.8mm

8 CET average: 14.9 Rainfall: 244mm

9 CET average: 15.6 Rainfall: 186.9mm

The best summers in that period tended to end in "3" "5" and "9" whilst the poorest tended to end in "2" and "8"

Another interesting fact about summers ending "8" is that there is only one July in that period (1888-1998) actually got above a CET of 16.0 (1928 with 16.1)

Using England and Wales sunshine figures

The sunshine average for summers ending in "5": 591.3hrs

Sunshine average for summers ending in "8": 472.3hrs that compares to summers ending in "2" with an average of 513.4hrs

Taking this into account then the summers ending in "8" have been the poorest overall

Manchester Summer Index average

For summers ending in "8": 193

For summers ending in "5": 233

These may well be interesting, but from a statistical point they mean absolutely nothing! You'd be pretty hard-pressed to find any meaningul correlation between weather and the last number of a year.

[nkaol2001]

Firstly, i will start by saying that i created this thread to discuss the upcoming summer prospects, so don't feel pressured to making a forecast because at this early stage, it would most likely be wrong, this is to discuss the variables ect...

That aside, i am personally a supporter of teleconnections, and as such, my first post in this thread will discuss this...

IMO, there are three main variables (leading modes), which make up a large percentage of a succesful forecast, these being..

1) ENSO state

2) QBO state

3) AO state

It is my personally belief that these three teleconnections are invariably linked.

In regards to the ENSO state, we are currently in moderate La Nina conditions. La Nina is correlated to lower than average angular mommentum (GLAAM), which essentially means that when La Nina conditions are present, there is typically a slow moving weather pattern. As well as the actual state of La Nina, it is my belief that whether La Nina is weakening or strengthening is also important, because La Nina is currently weakening, this teleconnects to a progressively less slow moving pattern, but a anticyclonic pattern, which in summer is correlated to above average temperatures.

In regards to the QBO state, during March, the QBO switched modes, and is now in a westerly mode, which is correlated to lower than average pressure in the Tropics, and mid-lattitude High pressure belts as a response, as well as stronger statospheric winds around the pole (stronger Polar Vortex), it is my belief that with a strengthening westerly QBO during the summer, this will correlate to a higher chance of mid-lattitude blocking.

In regards to the AO state, it is essentially a measure of the temperature in the statosphere at high lattitudes, and we are currently seeing a stratospheric cooling event, which is correlated to lower than average pressure over the poles (stronger Polar Vortex), the AO is quite strongly correlated to the NAO, meaning that when the AO is positive, the Azores High and Icelandic Lows are stronger, whereas it is visa versa during a neagative AO.

Tying these teleconnections together, it is my belief that the UK will see higher than average temperatures, and lower than average rainfall this summer. In regards to the first half of this summer, i expect a higher incidence of northerlies/easterlies than average, though i also expect the first half of summer to be the driest relative to average, to my knowledge, high pressure to the north of the British Isles would also lead to above average sunshine. In regards to the second half of sunshine, i expect this to feature a more orginised Polar Vortex, however with a signal for continued anticyclonicy, this should lead to higher pressure to the south east of the UK, with a greater amplitude of southerlies/westerlies relative to average, meaning that relative to average, i expect the second half of summer 2008 to be the hottest, though it is likely to be wetter and duller than the first half relative to average, however i do expect a continuation of below average rainfall and around average sunshine.

Very interesting! However,callme old-fashioned, but why cant we have " normal" summers like 1975,76etc.? These were dry,sunny,& warm throughout,especially 1975. Everybody would benefit, and the ground would have a chance to dry out a bit.Surely with G/W every summer should be dry,warm & sunny.......but sadly it seems to be the reverse of that What do you think!?

Regards, Derek.

[ANYWEATHER]

Very interesting! However,callme old-fashioned, but why cant we have " normal" summers like 1975,76etc.? These were dry,sunny,& warm throughout,especially 1975. Everybody would benefit, and the ground would have a chance to dry out a bit.Surely with G/W every summer should be dry,warm & sunny.......but sadly it seems to be the reverse of that What do you think!?

Regards, Derek.

Youre not old fashioned, you must be reminiscing!But I would not call 1975/76 normal summers? 1975 was very dry, which made the famous summer of 76 drought stricken and of course some very long hot weeks in that summer , and the global warming theory, youre as confused as everyone else.!

This year, well one thing is certain, {well almost} it will rain at some point at wimbledon!

A more sensible post from me on this topic will be on here very shortly!

[Gavin P]

Some time to go, so bare bones thoughts from me, but I'm expecting a very decent early summer - May through to mid June - followed by a very rapid desent downhill, culminating in a possibly appalling August!

Edited April 13, 2008 by Gavin P

[ribster]

I'll go with temps being average to slightly above, but with it being very wet, June being very wet indeed.

[Thundery wintry showers]

I may as well stand by my Annual CET predictions from the beginning of the year. Thus, my hunch is for:

• a slightly warmer than average June, with average sunshine and rainfall, overall pretty normal,
  
• a cloudy July with temperatures close to average, though nothing like as wet as last year,
  
• a warm, quite dry August with some thunderstorms, and sunshine generally slightly above average.
  

Overall, I'm thinking of a fairly warm summer, with averageness in June and July but a warm August, slightly below average rainfall, and average sunshine.

[William of Walworth]

Some time to go, so bare bones thoughts from me, but I'm expecting a very decent early summer - May through to mid June - followed by a very rapid desent downhill, culminating in a possibly appalling August!

Is that just a hunch or are you basing it on anything?

I'll happily go with the first half of your prediction though :lol:

I'll go with temps being average to slightly above, but with it being very wet, June being very wet indeed.

Spare the sensitivities of us Glastonburygoers PLEASE!!!

Thankfully, the complete oppositeness of your prediction from Gavin's tells me that you're both speculating ....

summer this year id guess wet maybe as bad as last year, wettest spell of the summer will be 23rd June- 6th July, clubland tv playing 'summer rain' right now gonna see a lot of it lol

Oh for heavens sake!!!!! <kills self> :lol:

Edited April 17, 2008 by William of Walworth

[Guest Mike W]

I think this summer will easily be in the top 10 hotteset Summer's list, maybe even top 5. Of course you never know which Summer now will take over 1976 for the top spot witht he continued warming of the climate. One thing for certain is that it is a case of when not if 1976 will get beaten, and it will happen sooner rather than later.

Edited April 17, 2008 by Mike W

[johnholmes]

is that a 'hopecast' or have you some proof to show us all?

[summer blizzard]

I think this summer will easily be in the top 10 hotteset Summer's list, maybe even top 5. Of course you never know which Summer now will take over 1976 for the top spot witht he continued warming of the climate. One thing for certain is that it is a case of when not if 1976 will get beaten, and it will happen sooner rather than later.

Just out of interest, could somebody list every summer with a CET of 17C+, i believe that 1976, 1995, 2003 and 2006 achieved this, however i am not sure which others did.

[johnholmes]

try the cet site

[North-Easterly Blast]

Just out of interest, could somebody list every summer with a CET of 17C+, i believe that 1976, 1995, 2003 and 2006 achieved this, however i am not sure which others did.

Summer 1983 also achieved a CET above 17*C.