The weekly update to the US Drought Monitor was released on Thursday with some locations in central Iowa, like Ames, degraded to a D1 (Moderate) drought classification. This degradation is due to a "flash drought" situation as this area has seen an abrupt change from adequate precipitation to very little during a high water demand period of the year. The featured chart nicely illustrates this change with trailing 31, 91, and 365 trailing day precipitation departures plotted in units of standard deviation. The coincident drought monitor classification is underlain. The rapid drop off in 31 and 91 day departures is juxtaposed with one year departures still well above average. It is getting very late in the growing season for rainfall events to make a difference for rapidly maturing crops, but any rains that do come soon will help!

Voting:
Good = 17
Bad = 0