Not a training base as such, its just the right conditions and a suitable place to do it. Base Training as its known (circuits) for new pilots is generally determined where it will take place on the morning its self. Favourite places are usually somewhere with a decent runway, not too much traffic and benign weather. Usual favorites are Teesside, Prestwick, Doncaster, Newquay etc. If the weather isnt suitable at one place, they will go else where. My own base training was planned to take place at East Midlands but due to weather we ended up doing it at Shannon. My colleagues ended up doing theirs at Ostend. Basically, it can vary day to day.