High resolution model simulation of precipitation and evaluation with Doppler radar observation

Surface precipitation is a key input parameter for hydrologic models. Validation of the precipitation field simulated by an atmospheric model is a first step in the development of a coupled atmospheric-hydrologic model. The objective of the present study is to simulate the surface precipitation using MC2 (Mesoscale Compressible Community Model) in a self-nesting mode. Two heavy rain cases in Quebec are examined. Using the first case (October 14-15, 1995), model parameters are adjusted to obtain a good simulation of the precipitation, when compared with that retrieved from Doppler radar measurements. The model is then applied to the second case (November 8-9, 1996) with no further tuning. The highest resolution used in both studies is 6 km. The spatial distribution of the simulated precipitation is very similar to that retrieved from radar measurements. The difference between the magnitude of the MC2 precipitation and radar estimates is of the same order as the uncertainty of the latter. A time shift is found in the simulated precipitation fields, which increases with the forecast lead time.