It especially shows up in the 300 inches a year lake effect snowfalls in
northern NY. You can hear it on 6 and 2 quite well. These were DC
grounded yagi antennas on all elements, so no corona available here,
thank you.

What makes you think the charge gradient and corona goes away with a
grounded element? Because there is never lightning and lightning never
hits a grounded object? Where dod you get that idea?

The earth is one terminal, the air and things in the air (like clouds)
have a charge difference.

Since the "sky" is one terminal and the earth the other with large
charge differential, why would you think connecting a tall sructure to
earth REDUCES the charge differential?

Also, K1RQG, who is net control of the EMENet on 14345 Sat and Sun
mornings, had it so bad from rain last weekend that he couldn't copy
most of the participants for a few minutes. And in a heavy rainstorm, I
have doubts that it had much to do with corona.

Why? Maybe you can answer this.....

Do we have more lightning, which is caused by a charge difference
between clouds and earth so severe it actually arcs for thousands of
feet, in heavy rain or on clear dry days?

Do the leaders and streamers form on clear dry days, or when the
weather is nasty?

You have it exactly backwards Tom. Grounding the element doesn't reduce
corna or reduce the charge difference between air and things in air
around the element and the element, it INCREASES the difference. If we
could float the element and allow the element to charge to the
potential of things around the element, the voltage gradient between
the element and things around the element would be reduced. Why do you
think the element, if we float the feedline, arcs to earth? It does
that because the air around the element is greatly different in
potential than the earth.

As for moisture, you also might do another test. Blow gently on a CRT
anode lead. See if your hot humid breath increases corona or decreases
it. Now go get a Windex bottle full of water and spray a mist on the
anode lead and see if the corna goes away, or gets worse.

I wonder how many people really understand there is a huge potential
difference between the air and earth even on a calm clear day, and
nasty weather can just make it worse.

73 Tom