Cranwell WMO 03379 – What “World Weather Attribution” didn’t know nor probably cared about.

53.03124 -0.50353 Met Office CIMO assessed Class 1 Installed 1/1/1917

The weather station was installed at RAF Cranwell on its original construction in the very early days of aviation. Archived temperature records run from 1920 in paper form up to 1939 with digital records from 1930 to date. The original manual records are unusually to the nearest tenth of a degree Fahrenheit which required well trained observers to be consistently accurate reading such a small unit though these would be effectively professionals in their field. The questions regarding Cranwell revolve more around modern standards rather than those of the original.

The original records show the site at 53.03219 -0.51218 some 600 metres away from the current location and near the present day medical centre as below.

The digital records overlap these manual copies, however, the former all erroneously show the coordinates of the current location and NOT the site detailed above.

For someone researching and trying to reconstruct an alternative temperature record (i.e. like me) this is very frustrating – it demonstrates the modern digital archives are not entirely trust worthy. Without detailed checking it would appear Cranwell has an unbroken record from the same site when it does not. The exact date of relocation is not evident and, indeed, there may have been more than one move as this major training aviation college developed over time. This is just one of the many quirks about this site – however, a close up view reveals a major issue.

My original list of stations by CIMO classifications showed Cranwell as Class 2, the updated list showed it actually “improved” to Class 1…….really what changed? Apparantly nothing. So is this really a Class 1 or even 2 site anyway?

Invaluable assistance from poster TonyF helped identify the large structure to the west of the screen as a combined diversion chamber/settlement tank. These are very common on airfields. Further research revealed the following.

“Purpose: A diversion chamber is used to control the flow of runoff water, directing it to appropriate outlets based on its quality or quantity. It helps manage stormwater and potential contaminants like fuel, oil, or de-icing chemicals that may accumulate on runways, taxiways, or aprons.

Purpose: A settlement tank (also called a settling basin or separator) is designed to remove suspended solids, oils, and other contaminants from runoff water before it is discharged or further treatment.

Importance at Airfields: Runoff from airfields often contains pollutants like jet fuel, hydraulic fluids, or rubber particles from tires. Settlement tanks reduce the risk of these contaminants harming ecosystems or clogging drainage systems, which could lead to flooding on runways.

At an airfield, a diversion chamber and settlement tank often function as part of an integrated drainage system:

1. Runoff from runways, taxiways, or other surfaces flows into the drainage system.
2. The diversion chamber assesses the water quality (manually or via sensors) and directs it appropriately:
   • Clean water to stormwater drains.
   • Contaminated water to the settlement tank.
3. In the settlement tank, pollutants are separated, and the treated water is either discharged safely or sent for further processing.

Taking this a step further, just how much these tanks are likely to hold was quite surprising.

“Typical Size Range

Settlement tanks at airfields are generally designed as part of oil-water separators or stormwater treatment systems. Based on civil engineering guidelines and drainage system designs:

Large Airfields (e.g., major international airports, large military bases):

• Capacity: 100,000 to 500,000 liters (26,400 to 132,000 gallons) or more per tank, with multiple tanks often used.
• Dimensions: Can exceed 15 meters long, 5–8 meters wide, and 3–4 meters deep (50 ft x 16–26 ft x 10–13 ft).
• Designed for high aircraft volumes and extensive paved surfaces.

I have indicated the tank at Cranwell above as 15 metres long and 6 metres wide thus only assuming 3 metre depth equates to 270,000 litres – 4 metre depth would give 360,000 litres. So what is this tank’s proximity to the Stevenson screen? Bear in mind what the CIMO regulations say for Class 2 { the Met Office suggestion of Class 1 is too preposterous to even contemplate and must be one of their “human errors” of default classification}

Below are the 10 metre and 30 metre annuli described as requirements above of meeting Class 2

THIS CONCLUSIVELY PROVES CRANWELL WEATHER STATION DOES NOT MEET CIMO CLASS 2.

So what about Class 3 i.e. –

Well its come down to millimetres from the actual tank structure but the tank surroundings and enclosure break the rules

Again millimetres to those minimum quarter million litres of settlement base and that tank enclosure fence will break the shade rule particularly being to the west.

This site does not meet Class 3 either so at very best Cranwell is Class 4 with an additional error margin due to siting of +/- 2°C.

The reason I have gone into such detailed research regarding Cranwell is to demonstrate just how important hard facts and data actually are to science – points which seem to be lost on institutions such as World Weather Attribution (WWA). This political organisation was established to enhance the ability to litigate against alleged “Climate criminals” and also to supply the likes of BBC News with suitably biased reports and “scientists say” type quotes.

On the 28th July 2022 WWA had miraculously managed to “research” , evaluate and publish their “findings” on a weather event of just 9 days earlier and then come to this quite astonishing headline grabbing conclusion.

“At three individual stations the 1-day maximum temperatures are as rare as 1 in 500 years in St James Park in London, about 1 in 1000 years in Durham and only expected on average once in 1500 years in today’s climate in Cranwell, Lincolnshire. “

This organisation (featuring Dr Frederike Otto) did not seem to be able to verify the likely accuracy of data from their chosen (i.e. cherry picked) comparison sites. Bear in mind this from the CIMO regulations. Class 5 (additional estimated uncertainty added by siting up to 5 °C)

St James Park is the lowest possible CIMO standard of Class 5S situated in the very centre of one of the world’s most intense urban heat islands. The London population of 500 years ago was just 50,000 compared to today’s 9 million. One does marvel at WWA’s immense “skills” at deriving the “odds” given the dramatic changes to the area.

Durham is also the lowest possible CIMO standard of Class 5, has experienced multiple relocations with bonded datasets, dubious metrology standards and again subject to urban encroachment…..but WWA somehow filtered all that out over a millennial time scale.

So to Cranwell (a site not open to general public scrutiny being on a military airfield) with over 12,000 feet of concrete runways, plus taxiways, hangars, aprons, buildings, jet aircraft et alia and sited with a Diversion/Settlement tank for extremely close company, we have a site prone to at least a Class 4 (additional estimated uncertainty added by siting up to 2 °C). However, add in likely jet blast effects from this busy training centre and this site is clearly unsuitable for any “climate” readings. For WWA to claim they can supply likelihoods of recurring weather events from such a massively altered landscape over the last 1,500 years is proof positive they are NOT a science body of any credibility whatsoever.

This whole charade demonstrates that the Met Office, and those to whom it supplies such site corrupted data for analysis, are untrustworthy.

Source: https://tallbloke.wordpress.com/2025/04/13/cranwell-wmo-03379-what-world-weather-attribution-didnt-know-nor-probably-cared-about/