On Monday, March 2, 2020 at 12:11:22 PM UTC, Julian Mayes wrote:
I thought I would pose this question here as there is a concentration of retired and (maybe?) current Met Office staff here with experience of observation networks.

In the current issue of Weather - in Weather Log - we find that 14 of the 21 UK sites listed give figures for days with snow lying and fog. Meanwhile, a further 4 just have a fog figure. 3 sites have no such data at all. My question is - does the existence of data imply that a station is staffed or part or maybe all of a day or is it simply a reflection of the appropriate sensor being installed? Are the observations comparable - for example, the snow depth sensor cannot find a representative patch of ground in the enclosure as the human can.

On a separate issue, no sunshine data is now available for Valley, Durham and Cambridge, each sites with long term records of sunshine on the old Campbell-Stokes instrument. (off hand I can't remember if it is Cambridge NIAB or the Botanic Gardens shown). It is even worse for the Europe list, including many capital cities which really must have sunshine data.

Many thanks, Julian
Molesey, Surrey.

I have never worked for the MetO, but my observation is that days of fog reported are highly misleading for a host of reasons

In the case of Camborne (manned) the issues are down to the 'fog in the vicinity' being reported as fog. (Camborne is close to an area prone to sea fog.) On one occasion Camborne recorded fog all day, when it was also the sunniest place in the UK (according to the MetO)

In reverse, Scilly (unmanned) can report sun all day when it's foggy. I did query that and got a reply that it was 'feature of the equipment used'. On a par when I queried different forecasts for St. Marys, Scilly heliport & airport, when they are the same place and got the reply the forecasts are different because 'they are based on different locations.'

The whole reporting of 'fog' seems a bit of a mess to me, as the recent fog at 09:00 thread shows. Not that the reporting of reduced visibility due to snow is a particular issue in Penzance!

Graham
Penzance