IEM Daily Feature
Tuesday, 20 July 2021
Tuesday, 20 July 2021
Waterloo Aridity Index
Posted: 20 Jul 2021 05:32 AM
Waterloo reported all of an inch of rainfall last week during Wednesday, which was the largest one
daily total so far this year for the site. Did that amount of rainfall make any dent in the drought
situation for the site? One way to measure that impact is to consider the aridity index, which
combines temperature and precipitation departures into one standardized value. The larger the
positive value, the higher the indicated water stress (demand for water from the atmosphere). This
metric is evaluated over trailing 30, 90, and 120 day windows. So while the rainfall and cooler
weather last week did help lower the 30 day aridity, it did not put much dent into the value over longer
time scales. Much of Iowa continues to need rainfall and the forecast is not very optimistic at the
moment of it arriving any time soon.
Voting:
Good = 9
Bad = 1
Voting:
Good = 9
Bad = 1