Re: Hailstorm.
It seems that there was a small low pressure air mass that was building to the north with the summer heat supplying the warm, moist air. Storm development was accelerated by orographic lifting over the mountains to the north, followed by cooling/condensing/raining as the storm moved south.
All the while, the surrounding front or air mass was supplying more energy into the storm, which allowed droplets to move up in the storm, freeze, fall, cool - and continue to take in enough energy to force the hailstones upward and form more layers. The whole up-down-layering-like-an-onion cycle repeated with the hailstones getting larger until they became to too heavy to be supported by the updrafts in the storm and fell.
The storm hail-making machine kept right on going because the energy that would have normally dissipated when the hail fell was continued to be fed by nearby warm/moist air mass that was all but staying in one place.
It was, you see, a perfect storm!