Tmmorris
I have flown that area a lot and the mountain route is really spectacular especially if you drop down to levels you would never admit too over miles of deserted landscape
Chances are even if the hills to the East of Snowdonia are clear you often get cloud build ups over Snowdonia but appreciate what you are saying!
There is no need to get a radar let down as over flying Caernarfon and then letting down over the sea works well but all to their own.
Pace