Hot week - guess the temperature competition

[matt111]

On 22/07/2019 at 19:33, matt111 said:

38.8°C in Kent on Thursday. 

So close (maybe)

[ItNeverSnowsInWindsor]

So what’s the chances of the quality control being successful for the 38.7c reading taken at Cambridge Botanic Garden ? It’s 0.6c higher than at Cambridge!

[chrisbell-nottheweatherman]

32 minutes ago, Summer Sun said:

Let's see how verification goes with the guidelines stated by the WMO

This is supposed to be the station

https://library.wmo.int/pmb_ged/wmo_8_en-2012.pdf page 20

That site does not appear to meet the requirements quoted at all...

[kold weather]

There were a lot of PWS showing 101-102f in the region. I see no reason why it wouldn't be realistic.

If it is, we have broken the record!

[sunnijim]

8 minutes ago, prolongedSnowLover said:

So what’s the chances of the quality control being successful for the 38.7c reading taken at Cambridge Botanic Garden ? It’s 0.6c higher than at Cambridge!

It will be great entertainment value I'm sure,claiming the highest UK temperature surrounded by greenhouses.

Seriously though,I would give it a 50/50 chance as we have no way of knowing when the site was last quality controlled by the Met office.

[sunnijim]

13 minutes ago, chrisbell-nottheweatherman said:

That site does not appear to meet the requirements quoted at all...

Why?

[chrisbell-nottheweatherman]

4 minutes ago, sunnijim said:

Why?

Bare soil near the screen, hedges not fences which will trap heat, in addition to which it's close to a huge glasshouse.

[Candice]

9 minutes ago, chrisbell-nottheweatherman said:

Bare soil near the screen, hedges not fences which will trap heat, in addition to which it's close to a huge glasshouse.

Actually, it's nowhere near the glasshouses.  It's now on a much grassier site as well

Edited July 26, 2019 by Candice

[chrisbell-nottheweatherman]

3 minutes ago, Candice said:

Actually, it's nowhere near the glasshouses.

Thanks for the clarification.  It'll be interesting as to whether the Met Office verifies it.

[Nick L]

If it's not a suitable site then I'll ask the question why are they even bothering to receive data from it?

I think it's fine.

[Earthshine]

All the experts are coming out now.  I'm sure if the site itself wasn't suitable the Met Office would not even consider the temperature reading.

[Derecho]

According to WMO guidelines here is my take. This is an aerial shot of the site or has it moved?

 

Class 1 - the highest

• T1) Ground within a 10m radius ‘mostly’ covered with lawn or natural and low vegetation (generally less than 10cm) representative of the region. Probably a fail as the path covers a good deal of the 10m radius. I'd fail it here due to the bare soil, class 2 I think but still over grass
o Open patches of bare ground acceptable if natural and representative of the region. but here I don't believe it is

• T2) Generally flat area within 10m of sensor. This area surrounded by generally open space with a slope of less than 1:3 (19°) that is considered to be representative of the large scale area. PASS, its flat

• T3) No irrigation or routine lawn watering system operational within 30m radius. Pass I presume

• T4) Sensor located at more than 100m from significant heat sources or reflective surfaces (buildings, roads, concrete surfaces, car parks, unnatural exposed ground areas, etc.). This also includes expanses of water even if only seasonal. Fail thanks to the greenhouse but its not too close....

o Open water can be excluded if representative of the region such as open coastal or large scale inland water/swamp/muskeg (ie. 25% of 100km radius, approximately equal in most directions).

A ‘significant’ source of heat (or expanse of water) is defined to have an impact if it comprises more than 10% of the horizontal surface within a 100m radius surrounding the sensor, comprises more than 5% of the horizontal surface within 30m radius or comprises 1% of the horizontal surface within a 10m radius.
10% of 100m radius circle = 3142 sq.m (32,212 sf)
5% of 30m radius circle = 141 sq.m (1368 sf)
1% of 10m radius circle = 3 sq.m (33 sf)

• T5) Sensor away from any subjectively determined heat source such as nearby infrastructure (ie. electronics boxes, metal mounting structures, etc.) that will have any affect on sensor. Minimum distance from sensor to nearby other objects at least 2x the height of the object away (2:1). Pass here.

• T6) Site not subjected to any jet blast, prop wash or helicopter downwash. No routine significant aircraft ground movement/parking or significant paved public highways within 100m. Fail but quite far away from roads etc.

• T7) Sensor in a ventilated solar radiation shield or enclosure. PASS

• T8) Sensor mounted between 1.2m and 2.0m above ground level. PASS

• T9) The maximum anticipated (subjective and non-extreme) snowdepth will remain at least 1m below the bottom surface of sensor shield or enclosure. Maybe a fail if a 1947 style winter came along but not relevant here

• T10) Sensor radiation shield away from all significant shade when the Sun is higher than 5 deg. above local geographic horizon. Fail due to the nearby trees.

So I'd say it should be official if none of the concerning factors got in the way of the highest temperature being recorded. My main concern would be the bare ground around the enclosure but there is at least 5 sq metres of grass surrounding the station in question.

Edited July 26, 2019 by Quicksilver1989

[sunnijim]

7 minutes ago, Quicksilver1989 said:

According to WMO guidelines here is my take. This is an aerial shot of the site:

Class 1 - the highest

• T1) Ground within a 10m radius ‘mostly’ covered with lawn or natural and low vegetation (generally less than 10cm) representative of the region. Probably a fail as the path covers a good deal of the 10m radius. I'd fail it here due to the bare soil, class 2 I think
o Open patches of bare ground acceptable if natural and representative of the region. but here I don't believe it is

• T2) Generally flat area within 10m of sensor. This area surrounded by generally open space with a slope of less than 1:3 (19°) that is considered to be representative of the large scale area. PASS, its flat

• T3) No irrigation or routine lawn watering system operational within 30m radius. Pass I presume

• T4) Sensor located at more than 100m from significant heat sources or reflective surfaces (buildings, roads, concrete surfaces, car parks, unnatural exposed ground areas, etc.). This also includes expanses of water even if only seasonal. Fail thanks to the greenhouse...

o Open water can be excluded if representative of the region such as open coastal or large scale inland water/swamp/muskeg (ie. 25% of 100km radius, approximately equal in most directions).

A ‘significant’ source of heat (or expanse of water) is defined to have an impact if it comprises more than 10% of the horizontal surface within a 100m radius surrounding the sensor, comprises more than 5% of the horizontal surface within 30m radius or comprises 1% of the horizontal surface within a 10m radius.
10% of 100m radius circle = 3142 sq.m (32,212 sf)
5% of 30m radius circle = 141 sq.m (1368 sf)
1% of 10m radius circle = 3 sq.m (33 sf)

• T5) Sensor away from any subjectively determined heat source such as nearby infrastructure (ie. electronics boxes, metal mounting structures, etc.) that will have any affect on sensor. Minimum distance from sensor to nearby other objects at least 2x the height of the object away (2:1). Pass here.

• T6) Site not subjected to any jet blast, prop wash or helicopter downwash. No routine significant aircraft ground movement/parking or significant paved public highways within 100m. Fail

• T7) Sensor in a ventilated solar radiation shield or enclosure. PASS

• T8) Sensor mounted between 1.2m and 2.0m above ground level. PASS

• T9) The maximum anticipated (subjective and non-extreme) snowdepth will remain at least 1m below the bottom surface of sensor shield or enclosure. Maybe a fail if a 1947 style winter came along but not relevant here

• T10) Sensor radiation shield away from all significant shade when the Sun is higher than 5 deg. above local geographic horizon. Fail due to the nearby trees.

So I'd say it should only be official if none of the concerning factors got in the way of the highest temperature being recorded. My main concern would be the bare ground around the enclosure.

Unless all the areas you have "failed' the site on are recent developments ( changed since the last yearly inspection) then there is nothing to suggest a problem from what I can diduce from the image available.

I find it hard to believe they would suddenly erect a glass house too close to the Stevenson screen,but possible I suppose!

[Derecho]

15 minutes ago, sunnijim said:

Unless all the areas you have "failed' the site on are recent developments ( changed since the last yearly inspection) then there is nothing to suggest a problem from what I can diduce from the image available.

I find it hard to believe they would suddenly erect a glass house too close to the Stevenson screen,but possible I suppose!

Well on closer look I think its a class 2 which is fine. If its moved to the location shown on the right then I think the bare soil isn't an issue. As you mention it depends on how recent site developments are as well. If changes had just appeared in the past 2 months or something like that then I could see the issue.

Edited July 26, 2019 by Quicksilver1989

[pandit-scholar]

27 minutes ago, Quicksilver1989 said:

According to WMO guidelines here is my take. This is an aerial shot of the site or has it moved?

 

Class 1 - the highest

• T1) Ground within a 10m radius ‘mostly’ covered with lawn or natural and low vegetation (generally less than 10cm) representative of the region. Probably a fail as the path covers a good deal of the 10m radius. I'd fail it here due to the bare soil, class 2 I think
o Open patches of bare ground acceptable if natural and representative of the region. but here I don't believe it is

• T2) Generally flat area within 10m of sensor. This area surrounded by generally open space with a slope of less than 1:3 (19°) that is considered to be representative of the large scale area. PASS, its flat

• T3) No irrigation or routine lawn watering system operational within 30m radius. Pass I presume

• T4) Sensor located at more than 100m from significant heat sources or reflective surfaces (buildings, roads, concrete surfaces, car parks, unnatural exposed ground areas, etc.). This also includes expanses of water even if only seasonal. Fail thanks to the greenhouse but its not too close....

o Open water can be excluded if representative of the region such as open coastal or large scale inland water/swamp/muskeg (ie. 25% of 100km radius, approximately equal in most directions).

A ‘significant’ source of heat (or expanse of water) is defined to have an impact if it comprises more than 10% of the horizontal surface within a 100m radius surrounding the sensor, comprises more than 5% of the horizontal surface within 30m radius or comprises 1% of the horizontal surface within a 10m radius.
10% of 100m radius circle = 3142 sq.m (32,212 sf)
5% of 30m radius circle = 141 sq.m (1368 sf)
1% of 10m radius circle = 3 sq.m (33 sf)

• T5) Sensor away from any subjectively determined heat source such as nearby infrastructure (ie. electronics boxes, metal mounting structures, etc.) that will have any affect on sensor. Minimum distance from sensor to nearby other objects at least 2x the height of the object away (2:1). Pass here.

• T6) Site not subjected to any jet blast, prop wash or helicopter downwash. No routine significant aircraft ground movement/parking or significant paved public highways within 100m. Fail

• T7) Sensor in a ventilated solar radiation shield or enclosure. PASS

• T8) Sensor mounted between 1.2m and 2.0m above ground level. PASS

• T9) The maximum anticipated (subjective and non-extreme) snowdepth will remain at least 1m below the bottom surface of sensor shield or enclosure. Maybe a fail if a 1947 style winter came along but not relevant here

• T10) Sensor radiation shield away from all significant shade when the Sun is higher than 5 deg. above local geographic horizon. Fail due to the nearby trees.

So I'd say it should be official if none of the concerning factors got in the way of the highest temperature being recorded. My main concern would be the bare ground around the enclosure but there is at least 5 sq metres of grass surrounding the station in question.

I have been to the Cambridge University Botanic gardens many times, since I study for a PhD at Cambridge. The Botanic Gardens is a very big site, and most of the greenhouses, if not all, are sited in one area of the gardens, well away from the weather station. 

 

Edited July 26, 2019 by pandit-scholar

[johnholmes]

From the Met Office

https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2019/provisional-hottest-day-on-record

Maybe (!) this will stop theamateur experts saying what is right or wrong about the site. Once Met Have inspected it then we will get the definitive answer=en of story?

[Derecho]

3 minutes ago, pandit-scholar said:

I have been to the Cambridge University Botanic gardens many times, since I study for a PhD at Cambridge. The Botanic Gardens are huge, and most of the greenhouses, if not all, are sited in one area of the gardens, well away from the weather station. 

Yup, the first site does appear to be close to buildings only and not a greenhouse (thought that was what it was from the aerial view). This is also from a class 1 perspective so these are guidelines for the very best meteorological stations. Still meets the required standard I think as I can't imagine there are many class 1 stations, as many of these are long running stations that came along before the guidelines anyway.

I think the record will stand.

[Derecho]

Additionally even if its not a class 1 station, comparisons between Kew and Heathrow from July 2015 dispel any concerns with regards to the data.

https://www.carbonbrief.org/met-office-wind-data-dispels-doubt-about-cause-of-heathrow-high-temperatures

[Wilxy]

Another picture of that site possibly recording the 38.7C but can't tell for sure as it was the only angle I could get!

[DaveL]

32 minutes ago, pandit-scholar said:

I have been to the Cambridge University Botanic gardens many times, since I study for a PhD at Cambridge. The Botanic Gardens is a very big site, and most of the greenhouses, if not all, are sited in one area of the gardens, well away from the weather station. 

 

I think the concerns are more about the open area surrounding the station enclosure, as it looks from supposedly 2019 Google Maps images to be bare earth or something else with a dark colour. Could be that it's all changed by now of course as there seems to be significant ongoing development there,  and grass grows. Have you seen it recently and if so is it back to a more normal area of short grass?

Edited July 26, 2019 by DaveL

[feb1991blizzard]

35 minutes ago, johnholmes said:

From the Met Office

https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2019/provisional-hottest-day-on-record

Maybe (!) this will stop theamateur experts saying what is right or wrong about the site. Once Met Have inspected it then we will get the definitive answer=en of story?

What i don't get though John is they can definitively say somewhere that reached 38.1 is validated immediately, yet somewhere else has 38.7, oh well we will have to have a look at it, surely they should validate it as an official weather station if it is fit for purpose and then any readings from then on are official, its almost like some stations are semi-pro and some are pro.

[James102]

Hi, I visited the Cambridge Botanic Garden site this morning and have uploaded three photos to Wikimedia Commons where you can see the current extent of bare soil and vegetation:

https://commons.wikimedia.org/wiki/File:Cambridge_Botanic_Garden_Weather_Station_from_the_South_West.jpg

https://commons.wikimedia.org/wiki/File:Cambridge_Botanic_Garden_Weather_Station_from_the_North_West.jpg

https://commons.wikimedia.org/wiki/File:Cambridge_Botanic_Garden_Weather_Station_from_the_West.jpg

 

 

Edited July 26, 2019 by James102

[Mapantz]

I was right! It is down to that wheelbarrow!

[Mapantz]

12 minutes ago, feb1991blizzard said:

 its almost like some stations are semi-pro and some are pro.

That's exactly what they are. Some stations are automated, delivering data every minute, while others are manually checked.

[feb1991blizzard]

Just now, Mapantz said:

That's exactly what they are. Some stations are automated, delivering data every minute, while others are manually checked.

Think they need to standardise it tbh to avoid confusion, i am not for one minute suggesting anything sinister is going on or any bias towards higher temperatures by any stretch of the imagination but other people will think it, just think it pays in this day and age to have it uniform.