never heard of that. the crackling doesnt sound too good, though.

That actually sounds like a discharge.

If correctly installed the antenna has a DC connection to the earth grounding rod.

At RF where it is operating it is NOT grounded.

If the local voltage of the earth changes then the antenna can become a discharge path.

Long before an actual lightning bolt forms there is local discharge from the earth to the air.

If you drive some ground stakes a decent distance apart and then run wire between them you can often measure very high voltages between the stakes.

During an active thunderstorm VERY high voltages.
As a charged cloud move above you a current flows in the earth (called a displacement current) induced by the now moving 'static' charge in the cloud.

You should check the condition of the antenna's lightning arrestor and the connection to ground, but it sounds like things are operating as they should.

Maybe it was excited about the new fall TV schedule...