flow away
flow off

In this situation atmosphere simply flows off into space, driven by thermal energy.

Five large glaciers flow off the slopes of the mountain.

It seemed to gradually dissolve and flow off into other matters.

But then you win that last point and the relief just flows off you.

Once words began flowing off his tongue, he was not certain he could control them.

The artifact flowed off its stand as if it were mercury.

The woman was slim, attractive, with long brown hair flowing off her shoulders.

One tributary flowed off across the ground floor, but the main stream was up on the first.

His name flowed off her tongue without effort or pain.

Water flowed off her body and back to the lake like a series of waterfalls.