Re:Humid atmosphere

> Indoors or out on a same temperature very humid summer evening the
streamers >are about 4 feet long.  That's a full 25% improvement!  I've seen
this coil behave >this way over and over again. I'm certainly convincved!

Same conditions with me.  Definitely longer sparks in humid atmospheres.
Maybe you have a bleed off to ground.  Elevate your system.  And check all
your ground connections.  Good luck!
*** Magic Bill ***