Do hail stone fall down just when it is created?

In the moist air of the clouds, the water condenses on dust particles. At the altitude where this happens, it is usually below the freezing point of water, so it quickly freezes. If winds and updrafts keep these particles of ice in the moist air, they collect more water. Eventually, the weight of the ice particles overcome the updrafts and fall to the surface.

Edit: The updrafts are always present, due to the nature of the storm clouds.

Hailstones - or anything like sleet, snow, etc - are formed by the freezing of water. Water droplets rise up, and as the temperature keeps decreasing, they freeze at a certain point into a stone, after which this stone would start falling.

Certain studies say that the stone after falling, can enter an area with differenct conditions - causing it to maybe melt and start rising again. This keeps on happening and the stone keeps going up and down, until it doesn't encounter any more of the 'uplifting' conditions.

Whether hailstones are formed, or sleet or simply snow - depends on a lot of weather conditions.