Fish, A.K., D. Santos-Munoz, F. Valero, Universidad Complutense de
Madrid, Spain
A ten member
short range ensemble prediction system has been created based on the WRF model
using the ARW dynamic core. The
SREPS is a multi-analysis, multi-physics system using 5 different physics
configurations, and 2 sets of initial conditions provided by the ECMWF IFS, and
NCEP GFS systems. The SREPS is based on an earlier system developed by Santos
et al using the Penn State MM5 model, in order to make a comparison of the two
systems the same domains and vertical structure was used, and where possible
the same physics parameterisations. The SREPS is composed of an outer domain
with a 30 km resolution covering the North Atlantic, and a two way nested
domain with a 10km horizontal resolution covering the Iberian Peninsula. 36
hour simulations have been produced for a 4 month period from 1st
September 2006, to the 31st of December 2006. The SREPS 10m wind speeds
were verified at 73 sites across the Iberian Peninsula, with measurements every
6 hours.
The WRF based
ensemble has been shown to outperform the MM5 SREPS, obtaining better results
at both 1 and 2 sigma levels, and lower RMSE and BIAS scores. The improvements
in quality are likely to be as a result of improvements in the dynamics of the
models.