I have noticed the following on a few occasions and wonder if there is any
definite relationship. For instance, the other day the morning started off
virtually cloudless, by 9am (4 hours before midday) cloud started to form on
the Cuillins (mountains) at about 700 meters, this cloud persisted until
just after 5pm (4 hours after midday) when the cloud started to break up and
clear. A few weeks back the cloud that arrived on the tops at 11am was gone
by 3pm (2 hrs before - 2 hrs after)!. I also note this occurring regularly
in the winter months when cloud arrives at sun up and goes at sun down.

Any explanations, thought etc.