1. WINDSOR TORNADO STUDY - STMAS (updated 10/21/2009 by Huiling Yuan and Yuanfu Xie)

2. Simulation of Windsor tornado case, 22 May 2008, 1.67 km run STMAS initialization 1.67 km 301 x 313, test 21 and 41 levels background model: RUC 13km, 17 UTC hot start (cloud analysis) balance package from LAPS performed Boundary conditions (BCs): RUC 13km, 3-h RUC forecast (initialized at 15 UTC) WRF-ARW 1.67 km, 1-h forecast, 35 levels (81 levels tested) Thompson microphysics 10 min output Postprocessing: reflectivity

3. 00-01hr 800mb reflectivity initialized at 17 UTC 22 May 2005, mosaic radar vs. WRF forecast (STMAS), 1.7 km

6. 00-01hr reflectivity cross-section initialized at 17 UTC 22 May 2005, mosaic radar vs. WRF forecast (STMAS), 1.7 km

9. 00-01hr omega cross-section initialized at 17 UTC 22 May 2005, WRF forecast, 1.7 km

10. Simulation of Windsor tornado case, 22 May 2008, 800 m run STMAS initialization 800 m 257 x 257 background model: RUC 13km, 17 UTC hot start (cloud analysis) balance package from LAPS performed Boundary conditions: RUC 13km, 3-h RUC forecast (initialized at 15 UTC) WRF-ARW 800 m, 1-h forecast, 81 levels Thompson microphysics 10 min output Postprocessing: reflectivity

11. 00-01hr 800mb reflectivity initialized at 17 UTC 22 May 2005, mosaic radar vs. WRF forecast (STMAS), 800m

14. 00-01hr reflectivity cross-section initialized at 17 UTC 22 May 2005, mosaic radar vs. WRF forecast (STMAS), 800 m

17. Summary of Windsor tornado case, 22 May 2008 Initial conditions are the most important factor Little BC impacts for 1-h forecast Tested 5km, 1.7km, with different RUC BCs (e.g., 3-h fcst from15 UTC, RUC analysis at 18 UTC, etc.) Forecasts initialized at finer analysis are better than inner nesting. Hot start initialization is very important for tornado forecasting Resolutions (both horizontal and vertical) in initialization play an important role; parameters in model less important (vertical resolution).

18. Future Modeling Considerations Resolution (horizontal & vertical) Microphysics scheme Reflectivity calculation Impact of balance package