Regional Climate Model Simulation of Extreme Precipitation in North America

Friday, 19 December 2014: 5:15 PM
Kenneth Kunkel1, Xungang Yin2, Anne Frigon3 and Jacinthe Clavet-Gaumont3, (1)CICS-NC/NCDC, Asheville, NC, United States, (2)ERT, Inc., Falls Church, VA, United States, (3)Ouranos, Montreal, QC, Canada
Regional climate model (RCM) simulations from the North American Regional Climate Change Assessment Project (NARCCAP) and additional simulations from the Canadian RCM (CRCM) were analyzed for changes in extreme precipitation. Metrics of extreme precipitation included annual maxima and 30-yr maxima of 24-yr, 48-hr, 72-hr, and 120-hr total precipitation. These are being compared with U.S. observations of these extremes for the reference period of 1971-2000. One particular aspect of interest is the spatial variability of extreme amounts in the model simulations. Preliminary results indicate that this spatial variability is quite large. This is of central interest because these simulations are being used to estimate future changes in extreme rainfall engineering design values. We are addressing two questions. One, is the model-simulated variability similar to observed variability. Two, how should this variability be interpreted, specifically how much is sampling noise and how much is forced by local features.