AEMET-γ-SREPS: convection-permitting EPS at the Spanish Meteorological Agency
Alfons Callado Pallares
Spanish Meteorological Agency
Noon Mar 1 in Room 2155
Abstract: Since 2004 the Spanish Meteorological Agency
(AEMET) has been running operationally a limited area ensemble
prediction system (LAM-EPS) for the Iberian Peninsula. Until 2014 and
nearly for a decade, this 25-km LAM-EPS called AEMET-SREPS (AEMET Short
Range EPS) provided probabilistic products to forecasters with a
performance which largely overcome ECMWF-EPS.
Since 2014 a
2,5-km convection-permitting LAM-EPS named AEMET-γ-SREPS has been
developing with the main goal to forecast mesoscale high impact events
as heavy precipitations estimating their uncertainty.
The
AEMET-γ-SREPS, as its AEMET-SREPS predecessor, is a multi-model
multi-boundary conditions EPS. This configuration has turned out to be
the best EPS technique based on probabilistic verification when
compared with other single-model techniques. AEMET-γ-SREPS initial and
boundary conditions’ synoptic uncertainties are dealt through analyses
and forecasts coming from 5 deterministic global NWP models with
independent assimilation processes: IFS from ECMWF, GFS from NCEP,
ARPEGE from MeteoFrance, GSM from JMA (Japanese) and GEM from CMC.
Model errors and uncertainties are taken into account using HARMONIE (2
configurations), WRF-ARW and WRF-NMM convection-permitting models. As a
result a 20 member EPS is achieved, combining 5 BCs with 4 NWP models.
AEMET-γ-SREPS
is currently daily running without assimilation and the work plan is to
provide the first probabilistic forecast products during the
forthcoming spring.
Future improvement prospects for 2016 are
to use LETKF (Local ensemble Kalman Filter) assimilation technique and
complement model uncertainties with SPPT (Stochastic Perturbations of
Parameterisations’ Tendencies) and surface parameters perturbations.