Supercell Features

• Rain Free Base or area of storm (Vault) -- area in which updraft is so strong that no precipitation can fall through to the ground;
• Dynamic Pipe Effect -- updraft becomes so strong that no air can pass into the center of it from the sides, but can from above and at its bottom; updraft is so strong that it can be visualized as a solid object deflecting ambient flow outside of the storm;
• Rear Flank Downdraft -- lower mid tropospheric air (in the Elevated Mixed Layer) encounters the storm from the upwind (usually southwest) side; some is deflected around the storm and some deflected downward to the ground and is called the Rear Flank Downdraft that has its own outflow boundary/gust front;
• Back-sheared Anvil -- divergence at the top of the storm is so strong that the anvil spreads backwards against the southwest flow in the mid troposphere, producing a lip to the anvil (knuckles)
• Wall Cloud -- area in which the moistest inflow air is tilted into the updraft with a very low LCL, producing a cloud feature that hangs down from the cloud base in the vault area;
• Tail Cloud -- elongated narrow cloud extending into the wall cloud, sometimes referred to as a Beaver Tail, formed by either gradual ascent or by parcel lofting along forward flank outflow boundary;
• Flanking Line -- storm towers along the Rear Flank Downdraft building into the main updraft instead of developing into separate thunderstorms.