Here we go again.
Forecast max temperature underestimated again for Plymouth Mt Batten in these conditions.
Forecast sunny all day. Correct.
Forecast max temperature 13°C. Wrong.
Actual max temperature 15.2°C.
Max temperature in my garden Stevenson screen 17.0°C.

Can't understand why UKMO model always messes up in these conditions.
Surely having forecast cloudless conditions, it is comparatively easy to forecast max temperature?

Len
Wembury, SW Devon