1. ARPS( Advanced Regional Prediction System ) Version 4.5.1. Center for Analysis and Prediction of Storms (CAPS), Oklahoma University tridimensional compressible non hydrostatic resolution 1km Navier-Stokes equations Generalized coordinate system Parameterized microphysics (Kessler and Lin)

2. Main Equations Prognostic equations for u, v, w,, p’ and Where: : water vapor, cloud water, rain water, cloud ice, snow and hail (graupel) Equation of state

3. Conservation equations for mixing ratios (vapor q v, cloud water q c, rain water q r, cloud ice q i, snow q s and hail q h. ) advection sedimentation mixing Sources (microphysical processes)

4. General simulation parameters. Domain: 90x96x20 km Horizontal Resolution : 1 km Vertical Resolution : 0.5 km Time Resolution: 6 s Lateral Boundary Conditions: Open (Klemp and Wilhemson, 1978) Top and Bottom B.C. Zero normal gradient Considered: Orography, Radiative effects, Land Use, Coriolis. July 2, 2001 Severe storm

5. Convection initiated with an ellipsoidal perturbation Θ max = 4  K Central coordinates: x=50 km, y=37 km, z=1.5 km Dimensions: 10x30x1.5 km (Simulating the form and dimensions of a preexisting storm) Control output : every 60 s Total simulation time: 3 h

6. Environment: Radiosounding 13:00 LST Camagüey, Cuba (21°25' N, 77°10' W)

7. Domain: Camagüey, Cuba (A 90 x 90 km square, with lower-left vertix at 21°25' N, 77°10' W)

8. Domain: Camagüey, Cuba (A 90 x 90 km square, with lower-left vertix at 21°25' N, 77°10' W)

9. Sounding for July 21, 2001

10. Hodograph

11. t = 30 min., t = 50 min., t = 70 min Vertical Vorticity (x 10 -5 s -1), z = 6 km w(m/s) Vertical Vorticity, z = 9 km

12. t=50 min, z=9 kmt=70 min., z=9 km Reflectivity (dBZ)n and w (m/s) W(m/s) 32 48 60

13. q c and q R (g/kg) for the W max. slice in the Y-Z plane q i and q H (g/kg) for for the W max. slice in the Y-Z plane

14. q c and q R (g/kg) for theW max. slice in the Y-Z plane q i and q H (g/kg) for theW max. slice in the Y-Z plane

15. Trajectories of the centers of both cells and the center of the system. Point labels indicate simulation time. Left moving cell Center of the system Right moving cell Left moving cell Center of the system Right moving cell

16. CAPPI 3-4 km

17. CAPPI 9-10 km

18. CONCLUSIONS Low precipitations supercell system, generated in an environment of high instability, and clockwise turning hodograph with low wind speeds at the lower levels and strong, and nearly unidirectional wind shear at heights from 6 to 12 km. Split storm structure, more clear at upper levels Left moving cell disspated by the entrainment of cold air, generated in the central downdraft at low and middle levels, conditioned by the wind profile.