1. Latest results in verification over Poland Katarzyna Starosta, Joanna Linkowska Institute of Meteorology and Water Management, Warsaw 9th COSMO General Meeting, 18-21 September 2007, Athens (Greece )

2. Work report – WG5, Poland: 1.Verification of surface parameters using 56 SYNOP stations. 2.Verification of precipitation using 308 rain gauges. 3.Verification of upper-air parameters using 3 TEMP stations 4.Case study – verification in QPF experiments 5.CVS – compilation of package

3. The results of verification of surface parameters for period January 2007 - June 2007 will be presented. The following meteorological elements were analysed: 2m temperature, 2m dew point temperature, sea level pressure, 10m wind speed. The meteorological variables forecasted by the model were compared with synoptic data from 56 Polish synoptic stations. Mean error (ME) and root mean square error (RMSE) were calculated using 12 forecast terms (spaced every 6 hours) taken for a 72 hour forecast starting at 00 UTC. The error estimators were calculated for all stations and for whole country area. Verification of surface parameters using 56 SYNOP stations

4. Standard deviation and mean error at Polish SYNOP stations vs. Forecast from 00 UTC

5. Mean error, diurnal cycle, the first day of forecast

6. The results of verification of 24-h accumulated precipitation from January 2007 to June 2007are presented below. For precipitation we calculated indices from the contingency table for 24h accumulated forecast data and data from 308 rain gauge stations for 3 day forecast range (1-day, 2-day, 3-day). Thresholds 0.5, 1, 2.5, 5, 10, 20, 25, 30 mm were used for a verification of precipitation. For each threshold the following scores were calculated: FBI (Frequency bias index), POD (Probability of detection of event), PON (Probability of detection of non-event) FAR (False alarm rate), TSS (True skill statistics), HSS (Heidke skill score), ETS (Equitable skill score).

7. Indices for 24h accumulated precipitation, 3 days

8. Indices for 24h accumulated precipitation day1 day2 day3 January June

9. The precipitation over Poland is over predicted. The overestimation is much higher for heavy precipitation especially in the summer. The major criteria used for selection of the events were the overestimation of maximum values or false prediction of precipitation occurrence. The four precipitation events were selected : 3 May,4 May,10 June, 9 August. The cases choosen were dominated by grid scale precipitation. The following versions of the COSMO model were used in experiments: 3.19 for 1st set of experiments (20) and 4.0 for 2nd set (5) of experiments were used. Case study, QPF project.

10. QPF, experiments 0-20, 10 June 2005, statistics

11. QPF, experiments A1-A6, POD-FAR indices

12. Conclusions The monthly and seasonal variation for the scores of 2m temperature is observed. The diurnal cycle of ME for 2m dew point temperature is observed. The RMSE and ME increases with the forecast time for sea level pressure. The ME is positive and increases during the forecast for 10m wind speed.