Abstract
The characterization of changes over the full distribution of
precipitation intensities remains an overlooked and underexplored
subject, despite their critical importance to hazard assessments and
water resource management. Here, we aggregate daily in situ Global
Historical Climatology Network precipitation observations within
seventeen internally consistent domains in the United States for two
time periods (1951-1980 and 1991-2020). We find statistically
significant changes in wet day precipitation distributions in all
domains – changes primarily driven by a shift from lower to higher wet
day intensities. Patterns of robust change are geographically
consistent, with increases in the mean (4.5-5.7%) and standard
deviation (4.4-8.7%) of wet day intensity in the eastern U.S., but
mixed signals in the western U.S. Beyond their critical importance to
the aforementioned impact assessments, these observational results can
also inform climate model performance evaluations.