In reply to Neil Anderson:
Weather Brecon Beacons National Park:
Mostly cloudy with scattered showers, mainly during the morning, locally heavy with a low risk of thunder. Hill fog will be persistent and extensive, especially during the morning. A slow thaw of lying snow.
Visibility: Mostly poor or very poor in hill fog during the morning, perhaps moderate later.
Hill fog:Periods of hill fog above 200 metres, slowly lifting.
Maximum winds above 400m Southeasterly 25 to 35 mph, backing easterly 15 to 20 mph.
Temperature: Valleys Plus 3 rising to plus 7 Celsius.
800 m Plus 2 Celsius.
Freezing level 1500 metres.
It won't be in on Wed. Colder Temps not forecast for another Week or so.