High pressure day; cumulus clouds are squashed up against the inversion and spread out, killing the lift as sun no longer strikes the ground .
Low pressure day, probably no inversion, nothing to squash the cu and they just grow and grow and turn black ..... and later in the day may generate an interesting cu nimb, with off the scale lift....
Which I experienced in Russia....I was just tucking under the edge, the rain was going up instead of down, and suddenly there was a flash and bang. The glider did an uncommanded 180 and we got the hell out of there! All you spam cans don't need to worry, you are flying around in your own Faraday cage. But even airliners ought to be a bit nervous. A K21 glider near Dunstable encounted a flash and bang, and the canopy disintegrated, the wings exploded, and both pilots did not need to eject as there was very little glider left to climb out of. One sprained his ankle on landing, I believe. The other one found the hair on the back of his head had been sizzled. When the wreckage of the K21 was recovered and studied by the boffins, the voltage of that particular lightning bolt turned out to be considerably in excess of the protection built into airliners......