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Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology Meteo. Swiss

Federal Department of Home Affairs FDHA Federal Office of Meteorology and Climatology Meteo. Swiss Conditional verification of all COSMO countries: first results COSMO General Meeting, September 2012, Lugano by the members of WG Verification

Objectives of conditional verification ü Contribute to COSMO model development ü Improve the understanding

Objectives of conditional verification ü Contribute to COSMO model development ü Improve the understanding of forecast errors ü Identify possible sources of errors in COSMO ü Contribute to guidelines on how to use COSMO forecasts Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 2

Feedback loop within COSMO operational application and development Physical aspects (atmosphere and soil) Data

Feedback loop within COSMO operational application and development Physical aspects (atmosphere and soil) Data assimilation Predictability and EPS Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch Conditional verification 3

Common conditional verification results • Cloud cover clearly stratifies the COSMO T 2 M

Common conditional verification results • Cloud cover clearly stratifies the COSMO T 2 M for overcast conditions forecast error of T 2 M (no matter whichsky conditions T 2 M for clear diagnostic) • Under observed clear sky conditions, the mean RMSE error has a pronounced daily cycle: All models underestimate daytime T 2 M and overestimate nighttime T 2 M ME • Under observed overcast conditions, this behaviour is not observed Autumn Spring 2012, 2011, ME and RMSE for many COSMO models Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 4

Searching for clues… • Additional stratification to look at cases with stable boundary layer

Searching for clues… • Additional stratification to look at cases with stable boundary layer → distinguish between dynamical and radiation dominated processes Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 5

COSMO-ME Conditional Verification T 2 m when observed TCC ≤ 25%

COSMO-ME Conditional Verification T 2 m when observed TCC ≤ 25%

COSMO-ME Conditional Verification T 2 m when observed TCC ≤ 25% & wind speed

COSMO-ME Conditional Verification T 2 m when observed TCC ≤ 25% & wind speed ≤ 2 m/s

COSMO-7 Conditional Verification T 2 m when forecast TCC ≤ 25%

COSMO-7 Conditional Verification T 2 m when forecast TCC ≤ 25%

COSMO-7 Conditional Verification T 2 m when forecast TCC ≤ 25% & wind speed

COSMO-7 Conditional Verification T 2 m when forecast TCC ≤ 25% & wind speed ≤ 2. 5 m/s

Searching for clues… • Additional stratification to look at cases with stable boundary layer

Searching for clues… • Additional stratification to look at cases with stable boundary layer → distinguish between dynamical and radiation dominated processes → in calm wind conditions, the underestimation of the daily temperature amplitude is even more pronounced→ overestimated thermal mixing (minimal diffusion coefficient? ) Nighttime overestimation from insufficient radiative cooling? Thermal conductivity of the soil? Daytime underestimation from underestimated sensible heat flux? Impact of soil moisture? Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 10

T 2 M with fcst soil moisture condition ME, RMSE dry conditions ME, RMSE

T 2 M with fcst soil moisture condition ME, RMSE dry conditions ME, RMSE wet conditions ME, RMSE no conditions Similar systematic error properties as for cloud cover conditions, but phase slightly shifted and different data sample → new box opened… Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 11

Precipitation with CAPE conditions ETS Unstable (CAPE>=50 J/kg) Stable (CAPE<50 J/kg) FBI Overestimation of

Precipitation with CAPE conditions ETS Unstable (CAPE>=50 J/kg) Stable (CAPE<50 J/kg) FBI Overestimation of preci amount for lower thresholds in high CAPE cases and ETS a bit reduced WG 5 COSMO General Meeting, Lugano 2012

Precipitation with CAPE conditions FBI Unstable (CAPE>=50 J/kg) Stable (CAPE<50 J/kg) ETS Conditional Verification

Precipitation with CAPE conditions FBI Unstable (CAPE>=50 J/kg) Stable (CAPE<50 J/kg) ETS Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 13

Precipitation with CAPE FBI Higher performance (in terms of ETS, also POD) in stable

Precipitation with CAPE FBI Higher performance (in terms of ETS, also POD) in stable conditions, CAPE condition displaced Unstablebut (CAPE>=50 J/kg) Stable (CAPE<50 J/kg) → find appropriate time period, other condition ETS Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 14

Conclusions ü Conditional verification provides us with tools for analysing rather complex COSMO model

Conclusions ü Conditional verification provides us with tools for analysing rather complex COSMO model errors ü Use of intensive measurement sites (e. g. sensible and latent fluxes for clear sky temperature error, soil moisture for temperature and dewpoint error) and radiosoundings ü Identify suitable stratifications for precipitation (e. g. appropriate time integrations for CAPE or convective time scale, so far no success with weather classes) ü Tight interaction with WG 3 and others Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 15

Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. stauch@meteoswiss. ch 16

Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 16

CAPE>50 CAPE<50 Very high POD values for unstable conditions, FAR not so different WG

CAPE>50 CAPE<50 Very high POD values for unstable conditions, FAR not so different WG 5 COSMO General Meeting, Lugano 2012

2 m. T, Td with dry or wet soil conditions Fall Winter Spring W_SO

2 m. T, Td with dry or wet soil conditions Fall Winter Spring W_SO Water content of first soil layer(kg/m 2) 1 cm. Td: Higher error in dry soil and larger underestimation 2 m. T: Higher error in wet soil and larger understimation Fall Winter WG 5 COSMO General Meeting, Lugano 2012 Spring

TD 2 M with soil moisture condition ME, RMSE dry conditions ME, RMSE wet

TD 2 M with soil moisture condition ME, RMSE dry conditions ME, RMSE wet conditions ME, RMSE no conditions Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 19

FF 10 M with grid point height ME, RMSE all stations ME, RMSE gp

FF 10 M with grid point height ME, RMSE all stations ME, RMSE gp height > 800 m ME, RMSE gp height < 800 m Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 20

FF 10 M scatter plot Winter 2012 Conditional Verification | COSMO-GM 2012, Lugano Vanessa

FF 10 M scatter plot Winter 2012 Conditional Verification | COSMO-GM 2012, Lugano Vanessa Stauch, vanessa. [email protected] ch 21