I find that the Met Office and BBC weather centre forecasts are only randomly accurate - i.e. useless.
In fact they are usually wrong about the current weather - so it is not surprising that the forecasts are so often wrong.
(I suspect - from the emphasis of their web pages - that these organization expend most of their effort, these days, on pretending to predict the long term future of the climate.)
Anyway, this means that - like a farmer in the old days, I need to do my own weather forecasting when deciding how to prepare for the day ahead.
This proves to be reasonably accurate based on three pieces of information.
1. Current weather. Generally weather in the next few hours resembles current weather.
2. Wind strength. No wind means the weather usually stays as it is currently, strong wind means that the weather could change a lot.
3. Wind direction.
South brings warm humid days and torrential rainstorms/ thunder in the evening.
South West (the prevailing wind in England, supposedly) is usually overcast but little or no rain (it falls on the Pennines before it gets to us).
West is often very windy, and can bring heavy rain (it comes straight off the Atlantic through the Tyne Gap).
North Winds are cold, and North East winds often rainy as well.
East winds bring very heavy rain showers, sometimes with deceptive dry patches between.
Looking at the type of clouds adds a bit of precision - but the above is good enough.