Prestatyn DCNN 7418 – Foehn Effects, Car Park effects or Dramatic effects?

53.34160 -3.41204 Met Office assessed CIMO Class 4 Installed 1/1/1932

For the purposes of supplying data towards the historic temperature records, weather stations should be representative of the natural environment of their region. The principal objective of the WMO CIMO Classification is to ensure minimum standards are met for national and international comparison. The Met Office has classified this site as Class 4 and are no doubt “correct” to the measured minimum requirements. But are main roads and large car parks typical of any region outside urban areas?

A reminder of the distances involved is here:

I doubt the authors of these international standards anticipated such literal interpretations rather than common sense guidance – a main thoroughfare and large car park in a busy sea side tourism centre is hardly representative of anywhere other than the immediate artificial heat island. Even on a low traffic day this site is still surrounded by large areas of black tarmac and concrete areas as shown below. The often floodlit “crazy-golf” alongside is equally unnatural and disruptive. On busy summer season holidays the often static queuing traffic will only ever elevate temperatures.

There are, however, other topical issues relevant to this and other north Wales weather site readings.

The all time “record” temperature nationally for the 24th November was 17.2°C recorded in 1970 at Prestatyn. However, yesterday 24/11/2024, this record was broken at Class 5 “Topsy Turvey” Santon Downham

This day’s weather event was somewhat sensationalised by a representative of the Met Office

Marco implores his X audience “To all other weather accounts out there..never feel afraid to post on twitter through fear of receiving harsh, often unjustified comments. If you’ve got the evidence to support your point your views and opinions are as important and relevant as any one elses“

Well taking Marco up on his offer (I do feel I qualify as a “weather account”)…….following his online statement yesterday of “Incredibly mild start to the day and with 18C in places still this morning the previous date record of 17.2C Prestatyn 1970 has been smashed” I pointed out that on the 23rd November 1906 (118 years plus one day ago) a temperature of 20°C was recorded in Lairg Scotland and asked him why he was sensationalising ( “Prestatyn 1970 has been smashed”) what was well within historic ranges. He chose not to respond.

The issues with Prestatyn are straightforward. It is poorly sited and over generously claimed to be CIMO Class 4 (potential inaccuracy by siting of 2°C) when in reality the site is so site compromised by extraneous heat sources that it should be dismissed as Class 5 (potential inaccuracy by siting of 5°C) . Its data should not be used for the historic climate record. Additionally the area is well known to exhibit Foehn Effect. The Met Office over emphasizes such rare events as demonstrated both in north wales and at sites such as Achfary and Cassley . To add such dramatic and sensational “reporting” from senior Met Office officials indicates a modern culture of “Record chasing” rather than a balanced evaluation of events.

Source: https://tallbloke.wordpress.com/2024/11/25/prestatyn-dcnn-7418-foehn-effects-car-park-effects-or-dramatic-effects/