Since the 1960s, meteorologists, climatologists and others have relied on the Palmer Drought Severity Index to tell them if a drought occurs.
The index developed by Wayne Palmer also allows users to determine the current severe drought.
It considers several different factors. The index will enable users to understand better water balance, which involves many different factors.
Precipitation
The index's first factor is precipitation. Obviously, the more rain or snow falls, the less likely an area is to be in a drought.