L. Docine et al., Evaluation of a simplified dynamical rainfall forecasting model from rain events simulated using a meteorological model, PHYS CH P B, 24(8), 1999, pp. 883-887
Citations number
15
Categorie Soggetti
Earth Sciences
Journal title
PHYSICS AND CHEMISTRY OF THE EARTH PART B-HYDROLOGY OCEANS AND ATMOSPHERE
This paper presents an evaluation of a simplified dynamical model from simu
lated rain events. This model is based on conservation of the rainwater con
tent of an atmospheric column and uses multi-scan radar data and surface me
teorological observations. A test of the model using radar data from Oklaho
ma City (USA) and the Cevennes region (France) has not clearly shown the mo
del efficiency compared to the simple extrapolation of radar observations.
This statement can be explained by the limited number of rain events availa
ble for testing the model and errors inherent in radar measurements. The pr
oposed evaluation is based on a mono-dimensional microphysical and meteorol
ogical model, which serves to simulate reference rainfall. The outputs of t
he meteorological model: rainwater content, cloud top temperature, surface
temperature, pressure and dew point are used for initialising the simplifie
d dynamical model as in the case of observed rain events. The evaluation of
the simplified dynamical model is performed by comparing forecasts to refe
rence rainrates. This comparison shows that the simplified dynamical model
performs better than the simple extrapolation method for short lead-times u
p to 30 min. This time is related to the response time of the rainwater atm
ospheric column. For longer lead-times, the dynamics of the simplified mode
l tends to a steady state characterised by a constant rainfall rate control
led by the source term. This result which has still to be confirmed makes t
he model adapted to requirements of urban hydrology. (C) 1999 Elsevier Scie
nce Ltd. All rights reserved.