Summer 2016

[DAVID SNOW]

10 minutes ago, Nick L said:

Gladly. Got it down to 17c today and it feels great. Anything above 22-23c in my room and I find it stuffy and uncomfortable. The problem being that my bedroom is on the ground floor, so I can't keep the windows open when I'm out. It can get really uncomfortable in the summer when sleeping for night shifts.

You could hire a small AC unit, for as little as 30 quid a week? Would solve your problem during hot and  humid spells, just a thought.

[Weather-history]

Not the greatest start to August

 

[Nick L]

44 minutes ago, DAVID SNOW said:

You could hire a small AC unit, for as little as 30 quid a week? Would solve your problem during hot and  humid spells, just a thought.

I don't think my landlord would appreciate it seeing as he's the one who foots the leccy bill!

Edited August 1, 2016 by Nick L

[Matthew.]

Chart 1:1 August 1962, Chart 2: 1 August 2016. Certain similarities The surpressed Azores high being the main difference of course.

Edited August 1, 2016 by Matthew Wilson

[Summer Sun]

The beeb are relatively confident warm air and high pressure will move in around mid-August

http://www.bbc.co.uk/weather/features/36947625

Edited August 1, 2016 by Summer Sun

[Wildswimmer Pete]

3 minutes ago, Summer Sun said:

The beeb are relatively confident warm air and high pressure will move in around mid-August

http://www.bbc.co.uk/weather/features/36947625

Jam next week? Like it's been since the beginning of June.  In the meantime yet another trough will shove the warmth well away.

[B87]

Our forecast showing below average temperatures and sun dominating August yet again.  Impossible to get a normal or good August these days!

[I remember Atlantic 252]

7 minutes ago, B87 said:

Our forecast showing below average temperatures and sun dominating August yet again.  Impossible to get a normal or good August these days!

I'll settle for those temps! wish it could be that warm in crappy area I live, too exposed to the NW

[B87]

Just now, I remember Atlantic 252 said:

I'll settle for those temps! wish it could be that warm in crappy area I live, too exposed to the NW

After a decade of crap Augusts, I won't be happy with anything less than average.  Fed up of 21-22c days with cloud and rain.

[MP-R]

14 minutes ago, B87 said:

Our forecast showing below average temperatures and sun dominating August yet again.  Impossible to get a normal or good August these days!

Got a nice weekend to come, and after that is anyone's guess. I think too many long range forecasts just default to sunny intervals and 21/22C when they don't know what to forecast lol. With high pressure over the UK and sunshine, London will not be 21/22C.

Meanwhile in the outback desert that the West Country has been for the last two months, we've had 17mm of rain today, which is 11mm less than July's total!

[weatherguru14]

22 minutes ago, B87 said:

Our forecast showing below average temperatures and sun dominating August yet again.  Impossible to get a normal or good August these days!

ha    the normal average for London is about 22c in August and that's what its basically saying.. You look at August 1995 and then that's  all you see.

[B87]

1 minute ago, weatherguru14 said:

ha    the normal average for London is about 22c in August and that's what its basically saying.. You look at August 1995 and then that's  all you see.

The normal average for August is 23.2c.  24c in early August and 22c in late August.  Most of that forecast has below normal temps and sunshine.

Edited August 1, 2016 by B87

[weatherguru14]

you are complaining about 1c  either way??..

[B87]

5 minutes ago, weatherguru14 said:

you are complaining about 1c  either way??..

Yes, because pretty much the last 11 Augusts have all been cooler and cloudier than normal.  We got 'lucky' in a few years like 2009, 2012 and 2013 which had normal or slightly above average temps, but were still very cloudy compared to the long term average.. 

Go back to 2000-2005, and all of those Augusts had normal temps and sun (apart from 2003 obviously, which was above). 

Edited August 1, 2016 by B87

[weatherguru14]

You take what you are given in the UK weather..August wont be blistering   hot and sunny...If we can get a fair amount of good days in there. You accept it.. This summer asnt been outstanding. But its not been  2007 or 2012.They were diabolical  even for the UK.

Edited August 1, 2016 by weatherguru14

[B87]

4 minutes ago, weatherguru14 said:

You take what you are given in the UK weather..August wont be blistening  hot and sunny...If we can get a fair amount of good days in there. You accept it.. This summer asnt been outstanding. But its not been  2007 or 2012.They were diabolical  even for the UK.

But a standard August in this part of the UK should see highs of 23c with over 200 hours of sun.  That isn't asking for much, that's just our typical August climate.  We haven't seen that since 2005, and the wait seems to be getting longer every year.

With an average high of 23c, you'd expect to see a couple of months with average highs between 21-22c in a decade.  You also expect to see a couple of months with average highs of 24-25c and we haven't seen any, we've only had the poor ones.

Edited August 1, 2016 by B87

[cheese]

15 minutes ago, weatherguru14 said:

ha    the normal average for London is about 22c in August and that's what its basically saying.. You look at August 1995 and then that's  all you see.

You are embarrassing yourself at this point. Just stop.

[weatherguru14]

Look i keep  mentioning our climate... You can look at stats until you are blue in the face..Does not mean the weather will behave as you want it to.. aslong as we get some summer days now and then.it will bide us over.. I agree we have been lacking long settled spells in summer for numerous years....But that's the way it is.

[weatherguru14]

3 minutes ago, cheese said:

You are embarrassing yourself at this point. Just stop.

are you a mouse?? is that why you are called cheese??

[Evening thunder]

1 hour ago, B87 said:

Our forecast showing below average temperatures and sun dominating August yet again.  Impossible to get a normal or good August these days!

Ah well, hopefully the UKMO/ECM would be better if they came off.

Anyway, 182.8 hours or 98% of average sun at Heathrow in July according to this link: http://www.met.reading.ac.uk/~brugge/PREV.html 

For sites including Heathrow it says: 'Climatological averages are for 30-years of pseudo-KZ observations in this case' which suggests that KZ sensors do indeed record lower totals than CS recorders here and in this case the average has been corrected to that. In other words with the current recording method you shouldn't expect 200 hours a month, indeed 2014's 183.6 hours is 97% of the estimated average on that site.
 

[B87]

25 minutes ago, Evening thunder said:

Ah well, hopefully the UKMO/ECM would be better if they came off.

Anyway, 182.8 hours or 98% of average sun at Heathrow in July according to this link: http://www.met.reading.ac.uk/~brugge/PREV.html 

For sites including Heathrow it says: 'Climatological averages are for 30-years of pseudo-KZ observations in this case' which suggests that KZ sensors do indeed record lower totals than CS recorders here and in this case the average has been corrected to that. In other words with the current recording method you shouldn't expect 200 hours a month, indeed 2014's 183.6 hours is 97% of the estimated average on that site.
 

Every other country that has introduced KZ sensors has seen an increase in sun hours.  They have a lower recording threshold than the CS recorder does. This study suggests that electronic sensors recording at 120W/m2 record about 10% more sun over the year than the CS. http://link.springer.com/article/10.1007/s00704-014-1125-z

Why have the Met Office adjusted the sun figures on the historic data page downwards?  July 2006 recorded 302 hours with a KZ sensor, yet on that page it has been adjusted to 266 hours to fit with CS measurements.  That is the case with many if not all months, but that and July 2013, Feb 2008 and June 2012 were other ones that I've noticed have changed from when they were first published.

KZ vs CS

Jul 2006: 302 vs 266 hrs (13.5% higher with KZ)

Feb 2008: 138 vs 130 hrs (6.1% higher with KZ)

Jun 2012: 132 vs 118 hrs (11.8% higher with KZ)

Jul 2013: 303 vs 268 hrs (13.1% higher with KZ)

 

The sunniest July and cloudiest June on this graph are 2006 and 2012 respectively, recorded with KZ sensor.  On the historic data page they have been adjusted downwards, to correspond with CS records.

"Currently, Kipp & Zonen monthly totals are adjusted to Campbell-Stokes equivalent values prior to generating the sunshine grids."

http://www.metoffice.gov.uk/climatechange/science/monitoring/ukcp09/faq.html

 

Edited August 1, 2016 by B87

[conor123]

Main problem with this summer, two warm spells surrounded by 50 days of consistent sunless grot!!! lost count now of how many mornings i've woke up to gloom!

[I remember Atlantic 252]

9 hours ago, weatherguru14 said:

are you a mouse?? is that why you are called cheese??

cheese gets upset about posts on here, his problem! never worry he'll grow out of it I hope, no surprise though about models downgrading though, ECM in particular seems to often underestimate low pressure and the Atlantic, go with GFS here, even that I think showing weekend 'too nice' to be true, underestimating the Atlantic

[Evening thunder]

10 hours ago, B87 said:

Every other country that has introduced KZ sensors has seen an increase in sun hours.  They have a lower recording threshold than the CS recorder does. This study suggests that electronic sensors recording at 120W/m2 record about 10% more sun over the year than the CS. http://link.springer.com/article/10.1007/s00704-014-1125-z

Why have the Met Office adjusted the sun figures on the historic data page downwards?  July 2006 recorded 302 hours with a KZ sensor, yet on that page it has been adjusted to 266 hours to fit with CS measurements.  That is the case with many if not all months, but that and July 2013, Feb 2008 and June 2012 were other ones that I've noticed have changed from when they were first published.

KZ vs CS

Jul 2006: 302 vs 266 hrs (13.5% higher with KZ)

Feb 2008: 138 vs 130 hrs (6.1% higher with KZ)

Jun 2012: 132 vs 118 hrs (11.8% higher with KZ)

Jul 2013: 303 vs 268 hrs (13.1% higher with KZ)

 

The sunniest July and cloudiest June on this graph are 2006 and 2012 respectively, recorded with KZ sensor.  On the historic data page they have been adjusted downwards, to correspond with CS records.

"Currently, Kipp & Zonen monthly totals are adjusted to Campbell-Stokes equivalent values prior to generating the sunshine grids."

http://www.metoffice.gov.uk/climatechange/science/monitoring/ukcp09/faq.html

 

Hmm, better email Reading Met Department and Rogger Bruuge.

The thing is, that is odd to me and goes against what various informed people and forum members have said before, CS sensors of course see (sometimes significant) over-reading due to exception of burn marks and observer interpretation differs between observers.

Anyway, since CS recorders are supposed to also have a threshold 120W m⁻², (which has been carried forward and implemented electronic sensors), surely that should eliminate under-recording due to a  'late wake up' effect? Indeed this standard was originally recommended in 1981 based on the average burn threshold of existing CS recorders at the time.

There are various of sources suggesting they over-read, some quotes from sources I found this morning:

Referring to the CS recorder, the WMO state:

Quote

It should be noted that the aforementioned problem of burns obtained under variable cloud conditions indicates that this instrument, and indeed any instrument using this method, does not provide accurate data of sunshine duration.

https://www.wmo.int/pages/prog/gcos/documents/gruanmanuals/CIMO/CIMO_Guide-7th_Edition-2008.pdf (chapter 8 p5)

 

Quote

An initial study by the Met Office to understand the relationship between the `new’ and `old’ type of sun- shine measurements suggests an average 10% reduction in sunshine from the KZ sensor com- pared with measurements made by cs recorders

http://onlinelibrary.wiley.com/doi/10.1256/004316502760195885/pdf


And this study by the Met Office (http://opensample.info/comparison-of-daily-sunshine-duration-recorded-by-campbell-stokes-and-kipp-and-zonen-sensors) describes the methods used to calculate the equations that are used to convert KZ to CS measurements, using actual overlaps in data recorded with both KZ and CS recorders at many UK stations:

A few quotes are

Quote

The main reason for the over reading of C–S recorders is the spreading of the burn during times of broken cloud, especially when the Sun is high and solar radiation is intense.

and

Quote

"On days that are overcast or with unbroken sunshine, however, there is little difference between the two measurements."

 

Quote

in the mid-range we see that C–S daily sunshine amounts typically exceed the KZ readings, due to overburn on days of intermittent sunshine, but towards the top end the values agree much more closely, and there is even a hint in spring and summer that the KZ values sometimes exceed the C–S values on the sunniest days

So perhaps on the sunniest days KZ values are a touch higher, but that is clearly outweighed by the most or almost all days that are not completely sunny in this country. I find it odd the Met Office would go against their own methods and adjust down (are you sure you didn't see the adjusted value and they then removed it or don't display it on the historic station data page to fit their description that "Sunshine data using a Kipp and Zonen sensor have been indicated by a "#" after the value", and "No allowances have been made for small site changes and developments in instrumentation."
That would make more sense to me.

This Heathrow anomaly just goes against all the evidence I have seen myself such as regional and district sunshine totals/anomalies, sunshine maps, that Reading uni page, and what I have seen this morning and before, and I find it hard to believe that for 10 years an odd persistently low sunshine anomaly has existed there, compared to the surrounding region. I basically made these posts because I am quite confident about this and think that if you don't realise it you will continue to be mostly disappointed in the future.

Edited August 2, 2016 by Evening thunder

[B87]

37 minutes ago, Evening thunder said:

So perhaps on the sunniest days KZ values are a touch higher, but that is clearly outweighed by the most or almost all days that are not completely sunny in this country. I find it odd the Met Office would go against their own methods and adjust down (are you sure you didn't see the adjusted value and they then removed it or don't display it on the historic station data page to fit their description that "Sunshine data using a Kipp and Zonen sensor have been indicated by a "#" after the value", and "No allowances have been made for small site changes and developments in instrumentation."
That would make more sense to me.
 

I am 100% certain that they posted up the KZ values originally for those 4 months, and then edited them to their current values several months/years later.  They added those KZ values onto that sun graph I posted, but didn't edit them back to CS.

It seems like different papers show different outcomes, regarding the translation of CS to electronic sun hours.  It's commonly thought that US hours are over-inflated, as they are around 150-300 hours sunnier than Canadian locations on the border.  Canada uses 120W/m2 whereas the US varies between 87W/me, 100W/m2 and the CS (in Boston).

On another forum I'm a member of, there are a couple of NZ members who have said that the change to KZ has caused an increase in sun hours.  Warsaw, Berlin and Paris have too (they all record similar sun hours to London ~1600-1700, but since adopting electronic sensors they are recording 2000+, 1800, 1750 hours respectively).

The CS recorder in use at Kew Gardens had a burn threshold of 139.5W/m2, as opposed to the KZ 120W/m2.  

Summers now seem a lot cloudier than they did pre-2006, even without looking at the data.  The rest of the year seems unchanged.  

Edited August 2, 2016 by B87