QPF verification of the 4 model versions at 7 km res. (COSMO-I7, COSMO-7, COSMO-EU, COSMO-ME) with the 2 model versions at 2.8 km res. (COSMO-I2, COSMO-IT)

Specifications:

• Dataset: high resolution network of rain gauges coming from COSMO dataset and Civil Protection Department 1300 stations

• Method: 24h/6h averaged cumulated precipitation value over 90 meteo-hydrological basins

•Model selection: run 00UTC, D+1

Precipitation verification comparison in 2008/2009 among the several COSMO-Model versions (Elena Oberto, Massimo Milelli - ARPA Piemonte)

The aims

• Long period verification (seasonal trend) (from djf’04 to mam’09)

1. Statistical indices for low thres (0.2mm/24h)

2. Statistical indices for high thres (20mm/24h)

• Verification ovest last year (200806-200905)

1. Cosmo-7/Cosmo-EU comparison

2. Cosmo-I7/Cosmo-ME comparison

3. Driving model comparison: ecmwf/Cosmo-I7/Cosmo-I2

4. Driving model comparison: ecmwf/Cosmo-ME/Cosmo-IT

5. Diurnal cycle for all the model

6. Spatial error distribution (latest season: MAM’09)

% correctly forecasted not-

events (specificity)

Seasonal trend (low thres)

• Bias reduction trend

• Seasonal cycle: big peak during summertime

• Biggest overestimation peak for cosmo-I7

• Underestimation for cosmo-7 during latest seasons

Seasonal trend (low thres)

• Stable trend/slightly worsening in time

• Best performance during spring/summertime

• Worsening for Cosmo-7 during latest seasons

Seasonal trend (low thres)

• False alarm number reduction esp. in wintertime

• Worse performance during summertime, esp. for Cosmo-I7

Seasonal trend (low thres)

• Slightly improvement trend

• Seasonal cycle: better during moist seasons, worse during dry seasons

Seasonal trend (high thres)

• Bias reduction trend, at least during last year

• Seasonal cycle: big peak during spring-summertime (convective period) seems to disappear during last summer (… why?)

• General good performance during last year

• Pronounced underestimation for Cosmo-7 during last seasons

Seasonal trend (high thres)

• Slightly improvement in time

• Worse performance during summertime (except 2007)

• Worsening for Cosmo-7 during last seasons

Seasonal trend (high thres)

• False alarm number reduction

• Worse performance during summertime

Seasonal trend (high thres)

• Slightly improvement trend

• Worse performance during summertime (except 2007)

Last year verif.: Cosmo-7/Cosmo-EU vs. thres

• Good performance for Cosmo-EU

• Underestimation for Cosmo-7

• More correctly forecasted non-events for Cosmo-7

Last year verif.: Cosmo-7/Cosmo-EU fixed thres, seasonal

• Good performance for Cosmo-EU

• Underestimation for Cosmo-7

• Positive trend for both the models

Last year verif.: Cosmo-I7/Cosmo-ME vs. thres

• Similar (good) performance: slightly better for Cosmo-ME

Last year verif.: Cosmo-I7/Cosmo-ME fixed thres, seasonal

• Similar (good) performance: slightly better for Cosmo-ME

• Positive trend for both the models

Driving model comp: Ecmwf/Cosmo-I7/Cosmo-I2 vs. thres

• Big gap between Ecmwf and Cosmo-model

• Cosmo-I7 slightly overestimation; Cosmo-I2 underestimation; Ecmwf overest. for low thres/ underest. for high thres.

• I7 equivalent or slightly better then I2 (even if less false alarm for I2)

Driving model comp: ecmwf/Cosmo-I7/Cosmo-I2 fixed thres, seasonal

• Big gap between Ecmwf and Cosmo-model

• Positive trend for both I7 and I2

• I2 Underestimation tendency

• I7 is generally better

Driving model comp: Ecmwf/Cosmo-ME/Cosmo-IT vs. thres

• Big gap between Ecmwf and Cosmo-model

• IT and ME –> quite similar, it is difficult to decide the winner

• IT tendency to overestimation

Driving model comp: ecmwf/Cosmo-ME/Cosmo-IT fixed thres, seasonal

• Big gap between Ecmwf and Cosmo-model

• IT and ME –> quite similar, it is difficult to decide the winner

• IT tendency to overestimation

Last year verif.: diurnal cycle for all the versions

Low thres High thres

• Bias overestimation peak during midday

• Spin-up problem for all the models especially COSMO-I7 and COSMO-I2

• General worsening with forecast time

• The spin-up seems to disappear, underestimation during the first 6h

• Bias overestimation peak during midday

• COSMO-7 underestimates

In general: slight improvement with respect to the previous year

To sum up• Long period verification (seasonal trend) (from djf’04 to mam’09)

1. General improvement trend

2. For low thres (rain/no rain): overestimation during spring/summertime with more probability of

detection but also more false alarms

3. For high thres: the worse skills during spring/summertime (convective period)

4. General Cosmo-7 worsening during last year

• Verification over last year (200806-200905)

1. Good performance for Cosmo-EU

2. Similar performance Cosmo-I7/ Cosmo-ME (slightly better Cosmo-ME)

3. Cosmo-I7/ Cosmo-I2 comparison: similar skill, underestimation I2

4. Cosmo-ME/Cosmo-IT comparison: similar skill, overestimation IT

5. Diurnal cycle: bias overestimation peak during midday, in general slight improvement with respect

to previous year

COSMO-7 COSMO-ME

COSMO-EU COSMO-I2COSMO-IT

COSMO-I7BIAS

200806-200905

10mm/24H

COSMO-7 COSMO-ME COSMO-I7Rel Error

MAM ‘09

COSMO-EU COSMO-IT COSMO-I2

COSMO-7 COSMO-ME

COSMO-I2

COSMO-I7POD

200806-200905

10mm/24H

COSMO-ITCOSMO-EU