Received Met. wisdom was "many a forecast has been ruined by looking at the actual from Valentia".
You would expect, in all innocence, that west and SW Irish obs would provide brilliant info on the onset of, or clearance of, rain.
That way madness lies.
This is not a dig at the observers, just a wry commentary on "sh1t happens"
Another folk lore aspect was "reconnaisance rain". This happened at Finningley more often than not. A confident, highly skilled [not to say expert] forecast of rain arriving at, say , 1200Z was rewarded with rain at 1000, causing the forecast to be amended, then ceasing by 1100, only to resume at the allotted time.