Question

ch 6 water and atmospheric moisture: precipitation
for hail to occur, what factors or conditions must exist?
tornados
strong up drafts
abundance of supercooled cloud droplets
cumulostratus clouds

Explanation:

Hail forms when there are strong updrafts (which keep ice particles aloft, allowing them to grow by accretion of supercooled cloud droplets). Supercooled cloud droplets (liquid water droplets below \(0^{\circ}C\)) are necessary for the growth of hailstone as they freeze upon contact with ice particles. Tornados are not a necessary condition for hail (though both can occur in severe thunderstorms). Cumulostratus is not a standard cloud type (the relevant cloud for hail is cumulonimbus).

Answer:

Strong up drafts, Abundance of supercooled cloud droplets.