1. I NVESTIGATION OF THE IMPACT OF M ICROPHYSICS O PTIONS ON I DEALIZED WRF S UPERCELL Catrin M. Mills Sara T. Strey-Mellema

2. M ICROPHYSICS Kessler: Warm rain – no ice Idealized microphysics (read- simple) Time-split rainfall Thompson: Replacement of Thompson et al. (2007) 6-class microphysics with graupel with ice and rain number concentrations (rather than idealized) predicted (double-moment ice) Time-split fall terms Millbrandt: New in Version 3.2 7-class microphysics with separate graupel and hail Number concentrations predicted for all six species water/ice species (double-moment) – 12 Time-split fall terms

3. H YPOTHESIS The microphysics scheme that best represents ice particles will have the strongest updrafts and strongest mesocyclone Model studies have shown that simulating ice effects storm dynamics, such that vertical vorticity is enhanced throughout the storm We expect that the more sophisticated schemes are necessary in generating cold pools that can generate horizontal vorticity and downdrafts that can tilt it into the vertical

4. A DVECTION T ERM : T HOMPSON VS. K ESSLER

5. D IVERGENCE T ERM : T HOMPSON VS. K ESSLER

6. T ILTING T ERM : T HOMPSON VS. K ESSLER

7. A DVECTION T ERM : T HOMPSON VS. K ESSLER

8. W- W IND kessler thompson millbrandt