Numerical Weather Prediction at MeteoSwiss

1
Numerical Weather Predictionat MeteoSwiss
29th EWGLAM meeting

• 8th of October 2007

2
Preoperational chain COSMO
COSMO-7 at 6.6km resolution
COSMO-2 at 2.2km resolution
Mesh sizes 3/50 6.6km 1/50 2.2kmMaximum
height 3122m 3950mDomains 393x338x60
7'970'040 GP 520x350x60 10920000 GPBoundary
conditions every 3h from IFS/ECMWF hourly from
COSMO-7 Forecasts 2 x 72h forecasts per day 8 x
24h forecasts per day (every 3h) Initial
conditions nudging to observations same, use of
radar (latent heat nudging) Pre-operational now
(operational beginning of 2008) 390 Gflops
sustained (816 processors 9 of peak) on Cray
XT4 at CSCS, Manno
3
Fuzzy verification for high resolution
precipitation
Fuzzy scores provide a wealth of information,

• but
• the results seems to be contrasting
• their interpretation is sometimes difficult
• contain too many numbers

4
Evaluation of the fuzzy scores
Application
Testbed
5
Evaluation of the fuzzy scores
Application
Testbed
6
A Fuzzy Verification testbed
Virtual truth (Radar data, model data, synthetic
field)
Fuzzy Verification Toolbox
Perturbation Generator
Analyzer
Realizations of virtual erroneousmodel forecasts
Realizations ofverification results

• Assessment of
• sensitivity (mean)
• reliability (STD)

• Two ingredients
• Reference fields, e.g. radar derived rain fields,
• Perturbations

Result Evaluation of the scores
7
Warning of extreme eventsusing calibrated
COSMO-LEPS products
30 years reforecasts 1 deterministic
run calibrate with climatology