Three supercell storm environments were utilized which produced a range of supercell storm types, roughly encompassing the range of low precipitation (LP) to classic (or moderate precipitation) to high precipitation (HP) supercells. A number of experiments were also performed with a low-shear environment (airmass storm). All three supercell environments were characterized by 0-5km shear magnitudes of about 30m/s. The HP supercell environment had no shear above 5km. The LP storm had very strong 5-10km shear, and the classic supercell had moderately strong 5-10km shear.
The airmass and HP supercell storms used the same temperature and moisture profiles which are the analytical functions used by Weisman and Klemp (1984). Both storm environments used half-circle hodographs with the wind shear confined to the lowest 5km, as in Weisman and Klemp (1984). The only difference in the environments of the two storms was the arc length of the hodograph: The airmass storm had a hodograph arc length (Us) of 10m/s, whereas the HP supercell storm had Us = 50m/s. These storms had Convective Available Potential Energy of about 2200J/kg.
The LP supercell hodograph was constructed by Straka and has slight curvature (veering) in the lowest 5km. In the 5-10km layer the shear is nearly linear with a magnitude of about 35m/s. The temperature profile was the same as for the HP storm, but the moisture was reduced above 3km altitude.
The classic supercell hodograph had strong curvature (veering) up to 3km and strong shear through 14km. It is a composite of two soundings from June 2, 1995, in the Texas panhandle (Gilmore, 2000). The CAPE for the classic storm was about 3000J/kg.
All the simulations used horizontally homogeneous initial conditions. Each storm was initiated with a warm, moist spheroid of radii 1.5
10 10km (12km for the classic supercell). Vertical grid spacing was fixed at 500m and horizontal spacing was 1.0-1.5km, depending on the storm type. The time step was 5.0s, and runs were carried out to 105min after initiation.