Unfortunately, Weekdays only,
https://www.gov.uk/government/publications/operational-low-flying-training-timetable
I think Llanbedr is the nearest airfield (surely there are others), it is mainly gliding but they are relaxed for visiting aircrafts, Cad East is the spectator point if coming by car
Seems someone got some training on how to fly the CJ at USAF acedemy 
