Evening ridge lift or wave?

There was some intriguing soaring this evening. The wind was fairly brisk, 15 knots, but it wasn't as turbulent as Tuesday, The thermals were long gone at 7pm but something was definitely happening downwind of the Borstal between 1000 and 1400 feet.

The air would start to bubble and turn into a gentle 'whoosh' of lift. Strangely, the lift was stronger at 1200 feet than it was at 1400 feet. It was also very difficult to stay in if you circled.

Could this be a tiny bit of wave, or a dollop of ridge lift?

I think next time these conditions re-occur we'll fly along the 'contours' and see if we can stay at 1200 feet by making 'beats' back and forth on our side of the airfield. If it is ridge lift, then we should be able to stay up for ages!

Evening flying does make you very determined to stay up - and patient enough to work every hint of lift!