Langen, 24-26 September 2003

COSMO-LEPS objective verification

Chiara Marsigli, Francesco Boccanera, Andrea Montani, Fabrizio Nerozzi,

Tiziana Paccagnella

ARPA-SMR, Bologna, Italy

COSMO-LEPS suite @ ECMWF

COSMO-LEPS INTEGRATION DOMAIN

LOKAL MODELL

10 KM HORIZONTAL RESOLUTION

COSMO-LEPS

Lokal Model scenarios

Probability Maps

       prob of 24h rainfall exceeding 20,50,100,150

mm

prob of 24h Tmax exceeding 20,30,35,40 C

         prob of 24h Tmin below -10,-5,0,+5 C

         prob of 24h Vmax exceeding 10,15,20,25 m/s

         prob of 24h snowfall exceeding 1,5,10,20 mm of equivalent water

Probability Maps

       prob of 24h rainfall exceeding 20,50,100,150

mm

prob of 24h Tmax exceeding 20,30,35,40 C

         prob of 24h Tmin below -10,-5,0,+5 C

         prob of 24h Vmax exceeding 10,15,20,25 m/s

         prob of 24h snowfall exceeding 1,5,10,20 mm of equivalent water

Deterministic products for each of the 5 LM runs:

Precipitation

Mean Sea level pressure

700 hPa Geopotential

850 hPa Temperature

Deterministic products for each of the 5 LM runs:

Precipitation

Mean Sea level pressure

700 hPa Geopotential

850 hPa Temperature

Transfer to Cosmo Partners

and other interested

Member States

Verification domain and stations

November 2002 – January 2003

Northern Italy

Bilinear interpolation

24h total precipitation

> 20mm/24h

> 10mm/24h

> 1mm/24h

> 50mm/24h

> 30mm/24h

> 50mm/24h

COSMO-LEPS

EPS SE+24h

COSMO-LEPS

EPS SE+96h

PROXY RAIN

LOKAL MODELL - 10 KM

FC +12h - +36h

PROXY RAIN

15/11 12UTC

PROXY RAIN

16/11 12UTC

November 2002

Northern Italy

Nearest point

24h total precipitation

> 20mm/24h

> 10mm/24h

> 1mm/24h

> 50mm/24h

> 30mm/24h

Weighting procedure

It is possible to decide (in real-time) if it is better to weight or not to weight?

Dependence from ensemble spread?

Flow dependence?

Concluding remarks

COSMO-LEPS is always more skillful than the 5RM EPS, sometimes also than SE, but more statistics is needed for high thresholds

Weighting both COSMO-LEPS members and ECMWF RMscauses a worsening of the scores

Verification against proxy-rain gives better results for higher thresholds

Verification will be soon extended to other COSMO countries (new data-set)

Fine