Science Source

Characterization of increased persistence and intensity of precipitation in the northeastern United States

Presents evidence of increasing persistence in daily precipitation in the northeastern United States that suggests that global circulation changes are affecting regional precipitation patterns
Analyzes meteorological data from 222 stations in 10 northeastern states—Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New York, Pennsylvania, Vermont, West Virginia, and the District of Columbia—using Markov chain parameter estimates to demonstrate that a significant mode of precipitation variability is the persistence of precipitation events
Finds that the largest region-wide trend in wet persistence (i.e., the probability of precipitation in 1 day and given precipitation in the preceding day) occurs in June (+0.9% probability per decade over all stations)
Finds that the study region is experiencing an increase in the magnitude of high-intensity precipitation events
Finds that the largest increases in the 95th percentile of daily precipitation occurred in April with a trend of +0.7 mm/d/decade
Discusses the implications of the observed precipitation signals for watershed hydrology and flood risk