grando-, grandi-, grani- +

(Latin: hail [ice], hail storm; sleet)

granineus
Hail shower.

Hail, what it is

Hail is said to be precipitation in the form of balls or lumps of ice, usually called hailstones.

Hail forms when strong currents of rising air, known as updrafts, carry water droplets high enough into a thunderstorm for the water droplets to freeze.

A strong updraft allows hailstones to grow large enough to reach the ground. In general, the stronger the updraft, the larger the hail.

While hailstones are ice, hail is mostly a spring and summer phenomena because the strong thunderstorms needed to produce hail are much more common during warm weather.

Ice that falls during the winter is almost always sleet; such as, raindrops that freeze on the way down to the surface of the earth. Winter storms can bring ordinary rain, freezing rain, and sleet; as well as, snow.

Other related "ice" units: crystallo; glaci-.