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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 COSMO Priority Project ’Tackle deficiencies in quantitative precipitation forecasts’ – how to evaluate results from the sensitivity runs? PP QPF Workshop, 8 March 2007, Langen

Classification by area mean and maximum precipitation - quantitative comparison of relative changes -

Classification by area mean and maximum precipitation - quantitative comparison of relative changes - Quick overview -ascii data of your mean and maximum values + documentation of the format you send PP QPF S. Dierer et al. 2

Classification of cases DATE INSITUTION Overestimation (+)/underestimation (-) Stratiform (strat)/convective(con) 06. 12. 2004 LM-DWD

Classification of cases DATE INSITUTION Overestimation (+)/underestimation (-) Stratiform (strat)/convective(con) 06. 12. 2004 LM-DWD + strat warm sector 18. 03. 2005 LM-DWD + strat orography 03. 05. 2005 LM-DWD + Strat+conv Warm front 21. 06. 2005 LM-DWD - conv Cold front 02. 2005 a. LMo + strat Cold front 22. 03. 2005 a. LMo + strat Warm front 12. 07. 2005 a. LMo + conv - 17. 12. 2005 a. LMo + Mainly strat orography 24. 09. 2004 LAMI - conv Cold front 10. 04. 2005 LAMI + conv Occluded front 17. 08. 2006 LAMI +/- conv front 09. 2005 LAMI + conv - 27. 03. 2005 LAMI - strat/conv front 01. 12. 2005 Euro. LM ? mainly strat ? 03. 12. 2005 Euro. LM ? Strat/conv ? 17. 12. 2005 Euro. LM ? strat/conv ? 15. 09. 2005 LM-HNMS + conv orography 23. 11. 2005 LM-HNMS + Strat+conv Cold front 26. 11. 2005 LM-HNMS +/- Strat+conv Warm+cold front 03. 05. 2005 LM-IMGW + strat Warm front 04. 05. 2005 LM-IMGW +/- conv cold front 09. 06. 2005 LM-IMGW - conv occluded 09. 08. 2005 LM-IMGW +/- ? cold front 23. 06. 2005 LM-NMA + strat+conv cold front 02. 07. 2005 LM-NMA +/- strat Cold front 12. 07. 2005 LM-NMA + conv - PP QPF S. Dierer et al. classification: - stratiform over- and underestimation and - convective over- and underestimation ? ? ? 3

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum in the sensitivity studies 06. 12. 2004 PP QPF S. Dierer et al. 18. 03. 2005 4

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum in the sensitivity studies 02. 2005 5 dt 20 6 lfsl 3 O ctrl 7 Rksl 3 1 wso 80 2 Wso 120 8 rkbott 3 Qv 090 9 rktp 4 Qv 110 10 oro PP QPF S. Dierer et al. 22. 03. 2005 11 micro 1 12 micro 2 13 micro 3 14 conmod 15 conkfb 16 conoff 17 rlam 01 18 rlam 50 19 sto 050 20 sto 250 21 sea 01 22 sea 40 5

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum in the sensitivity studies 17. 12. 2005 O ctrl 1 wso 80 2 Wso 120 3 Qv 090 4 Qv 110 PP QPF S. Dierer et al. 5 dt 20 6 lfsl 3 7 Rksl 3 8 rkbott 9 rktp 10 oro 11 micro 1 12 micro 2 13 micro 3 14 conmod 15 conkfb 16 conoff 17 rlam 01 18 rlam 50 19 sto 050 20 sto 250 21 sea 01 22 sea 40 6

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum

Winter cases with overestimated precipitation - change of 24 h area average precipitation sum in the sensitivity studies 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 06. 12. 2004 18. 03. 2005 02. 2005 22. 03. 2005 17. 12. 2005 O ctrl 1 wso 80 2 Wso 120 3 Qv 090 4 Qv 110 PP QPF S. Dierer et al. 5 dt 20 6 lfsl 3 7 Rksl 3 8 rkbott 9 rktp 10 oro 11 micro 1 12 micro 2 13 micro 3 14 conmod 15 conkfb 16 conoff 17 rlam 01 18 rlam 50 19 sto 050 20 sto 250 21 sea 01 22 sea 40 7

Summer cases with overestimated precipitation - change of 24 h area average precipitation sum

Summer cases with overestimated precipitation - change of 24 h area average precipitation sum in the sensitivity studies 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 03. 05. 2005 23. 06. 2005 ? 02. 07. 2005 ? 12. 07. 2005 O ctrl 1 wso 80 2 Wso 120 3 Qv 090 4 Qv 110 PP QPF S. Dierer et al. 5 dt 20 6 lfsl 3 7 Rksl 3 8 rkbott 9 rktp 10 oro 11 micro 1 12 micro 2 13 micro 3 14 conmod 15 conkfb 16 conoff 17 rlam 01 18 rlam 50 19 sto 050 20 sto 250 21 sea 01 22 sea 40 8

First ideas from the results… • None of the studies completely solves a QPF

First ideas from the results… • None of the studies completely solves a QPF problem, but some give a significant improvement for single cases like • changes of snow microphysics for winter precipitation overestimation • Initial humidity is of great importance • Runge-Kutta reduces mean precipitation in most of the cases • Decreased vertical exchange of heat and moisture (RLAM) tends to decrease mean precipitation PP QPF S. Dierer et al. 9

Rising some questions: • What’s the reason why Runge-Kutta reduces mean precipitation in a

Rising some questions: • What’s the reason why Runge-Kutta reduces mean precipitation in a lot of cases, especially stratiform winter cases? • What’s the effect of decreased vertical exchange decreasing mean precipitation? • Time step also effects results – due to increased call of physical schemes? • More detailed analysis of case studies is necessary to understand these changes… PP QPF S. Dierer et al. 10

Next steps will be… • Complete statistics for all runs and suitable classification •

Next steps will be… • Complete statistics for all runs and suitable classification • Find changes that have an effect for precipitation forecast • More detailed analysis of cases that show significant changes, especially if there’s no direct relation between change and precipitation, e. g. Runge-Kutta PP QPF S. Dierer et al. 11