The Met Office Library holds millions of daily rainfall observations in its archives. Though anyone can access these physical treasures in person, and on request by email, a lot of these records taken before 1960 remain hidden away.
Yet these data provide an excellent insight into the behaviour of our weather on a local scale. As good as computer models are they are still a distance away from being able to forecast thunderstorms and frontal rain at smaller resolutions. Data from the literally hundreds of smaller rainfall stations set up in Victorian times would provide local government agencies the ability to identify where rainfall is historically heaviest and therefore areas where flash flooding is a greater risk.
For a number of years some of the archives have been digitised with the help of citizen science campaigns; the records of the Ben Nevis Summit Observatory being one historic station now digitised.
Though AI has improved computers still struggle with handwritten records; the best method is still to scan them all by hand before an army of volunteers get to input them onto online spreadsheets.
The cost to scan the rainfall archive pre-1960 would be £100,000. Though this sounds a lot for a ‘nice to have’ digital archive it could save millions in the cost of reactionary local authority work thanks to measures taken to plan against problems with flash flooding before they appear.
Tracking the rolling 12-month daily rainfall total allows a ‘real-time’ look whether an area is experiencing a drought or a deluge.
This week’s figure represents the 8th highest at this date since 1962. So not unusual. Until you look at the jump since last year. Some 303.6mm the past 12-months just pips the same period in 1976-77.
What is perhaps most noticeable is that this year follows last year’s negative fall which was the largest since 1961.
It’s one rainfall station BUT the results suggest a climate that is swinging more violently from one extreme to the other.
The current site hosting Wanstead’s weather station has been running for 11 years next month; the automatic station uploading data every 10 minutes to the internet.
The 10-year averages from the station are now good enough to be listed on the Climatological Observers Link.
A look at the tenth month shows some interesting trends…
The 9am air pressure readings were not included in previous climate summaries owing to analogue barometers only giving approximate air pressure readings. The advent of AWS has changed that, particularly for independent amateur observers.
A look at the below graphic shows pressure lowest around the 21st, the stormiest weather of the month. Storm Babet in 2023 is proof of that.
Average daily windrun is how much wind there’s been during a 24 hour period. Again the 21st comes out as windiest.
Wanstead Meteo 
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