Weather modification is the act of intentionally manipulating or altering the
weather. The most common form of weather modification is
cloud seeding to increase rain or snow, usually for the purpose of increasing the local
water supply. Weather modification can also have the goal of preventing damaging weather, such as
hail or
hurricanes, from occurring; or of provoking damaging weather against the enemy, as a tactic of
military or
economic warfare. Weather modification in warfare has been banned by the
United Nations.