IEM Daily Feature
Wednesday, 09 February 2022

85% of month in one day

Posted: 09 Feb 2022 05:34 AM

From the somewhat obscure stats department, the featured chart presents the frequency of one day within a given month providing at least 85% of that month's total precipitation. Such an occurrence happened back on January 14th, with 1.03 inches of precipitation reported for Des Moines and the monthly total only reaching 1.21 inches making for 85.1% of the monthly total falling on that one day. The labels above the bar include the year of last occurrence and November 2021 is shown reaching the criterion with 1.35 inches falling on the 10th and only 1.54 total for the month! It is sort of interesting to see the large difference between November and December, which may be due to November being a dry month to begin with, but still subject to the occasional thunderstorm or single significant snow storm. Anyway, these events are very infrequent during the summer as heavy rainfall events like to beget other heavy rainfall events (positive feedback) and monthly totals are much higher on average making a single day total less likely to reach it.

Good = 11
Bad = 0