Hastings DCNN 5490- “Human Error.”

50.85580 0.56993 Met Office CIMO Rating Class 1 …but now Class 4 Installed 1/1/1934

In March this year via Freedom of Information Act I obtained from the Met Office the full list of Synoptic and Climate reporting weather stations, assessed for Temperature and Humidity by CIMO Classification.

Hastings was shown as Class 1. Looking at google maps above this rating appeared to be completely wrong. I visited the site to verify it was still there (it is) , take my own photographs and some measurements. Alongside the often traffic gridlocked A21 through route , adjacent to public toilets, surrounded by pathways and car parks, in a not inconsiderable urban heat island with shading trees and artificial vegetation this was certainly no Class 1 site. The response to my subsequent inquiry to the Met Office was very enlightening.

“Dear Mr Sanders

Thank you very much for your enquiry. This has highlighted an issue in our database. My original recorded inspection data was ‘CIMO Class 4’ (and I’ve reviewed the exposure diagram, which confirms), with the Stevenson screen exposure recorded as ‘Acceptable’ (and Satisfactory overall, taking into account the CIMO 4 rating).

The default CIMO rating is 1 on our site visit application (and Met O ‘Excellent’), so it looks like the class hasn’t been entered correctly, human error.

I trust this answers your question.

Sincerely

Angus Bruce BSc MIET

Regional Network Manager (South East England)”

I feel that response is perfectly clear – The Met Office system automatically assumes ALL their sites are both CIMO Class 1 AND “Excellent” (the latter their own unique assessment procedure) unless manually altered downwards. An analogy for this unusual “mark down” procedure would be an examiner assuming all students papers were a 100% score, only deducting marks for errors – a blank paper could potentially reflect perfection.

For clarity below is the Met Office justification for continuing to use their own assessment system alongside the CIMO ratings.

https://www.metoffice.gov.uk/weather/learn-about/how-forecasts-are-made/observations/observation-site-classification

The issue of a system loaded to perfection in default positions is obviously problematic where there is no apparent independent supervision and begs my question, “Would Hastings have continued in its star performer rating had I not intervened? ” Whilst this may seem a trivial point, there are significant practical implications to siting standards and derived “average” temperatures from these sites. A future post will cover “Cold Weather Payments” and how poor station siting can adversely affect these.

A further related issue is the covert nature the Met Office adopts with some of its data. I start my posts with freely available detail regarding each site such as location, elevation, drainage area etc. taken from their CEDA Archive. However,obtaining the CIMO rating of site quality is not openly available online.

The case of Hastings “Human Error” led me to query other site’s assessed quality with some surprising results – this will be followed up in my next post regarding the “Cassley” mystery.

Source: https://tallbloke.wordpress.com/2024/08/29/hastings-dcnn-5490-human-error/