It is early summer, and all day the weather has been developing toward thunderstorms. By late in the afternoon, dark clouds are banking up, and rain is threatening.

Eventually it begins, a gentle precipitation that patters on the dry woodland floor. The first peals of thunder roll across the sky, receding into the distance. Frogs begin calling softly, welcoming the moisture.

A first stormfront passes over, and for a while thunder rumbles ominously around the horizon. Soon another dark cloud bank approaches, and winds gust through the treetops. Small birds flit for shelter as the storm gathers and thunder gets closer.

This recording was made at our home in the bush in southeastern Australia. In late spring and early summer, we frequently have moisture-laden weather systems which move down across the continent from more tropical regions. Thunderstorms develop toward the afternoon, bringing with them unusually humid and muggy conditions (for our part of the world).

Recording these storms can be tricky; wind gusts get strong and buffet the microphone, and just when the storm gets really close and interesting, the rain often begins falling in bucketloads. So I had to wait for the right circumstances to make this recording.

A highlight, inaudible on the recording, was a flock of Spine-tailed Swifts, which unexpectedly appeared overhead. For a brief minute or two, I had 200 or so birds above me, streaking across the stormy skies as they surfed the stormfront. As suddenly as they appeared, the flock had passed over and disappeared.