Hail can only form in very specific conditions, and only in a very specific part of a very energetic thunderstorm. Rain or snow doesn't even need a thunderstorm - just any old storm will do.
For hail to form there needs to be a convective cycling of warm liquid water upwards at the front of a storm which then freezes. At that point it falls down towards the lower bits of the storm where the temps are above the freezing point. That ice ball then gets coated in liquid water, will cycle upwards again to freeze another layer over the first, and so on. At some point, it's so heavy that updraft winds can't carry it upwards, and it falls to the ground. It's shown more completely in [this diagram](https://i.imgur.com/pl1DDLX.jpg
As a result, the only place hail can really efficiently form is right at [the edge between the leading updraft and the trailing downdraft](https://i.imgur.com/gbG9Koj.jpg
), leaving a relatively narrow ground track of the place where hail can actually fall to the ground.
You can also determine the number of convective cycles the hail went through before falling to the ground by [looking a the cross section of a hail stone](https://i.imgur.com/ZgwHvS3.jpg
). Each layer there was formed from a single cycle of liquid coating and refreezing.