Anvil - As the equilibrium level is reached, the air and cloud material spreads out and the anvil is formed.  If the anvil is thick, smooth-edged and puffy like the lower part of the storm, then the storm probably has a strong updraft and is a good candidate to produce severe weather.  Also, if the anvil is streaming away from the storm in one particular direction, then the storm will be well ventilated by strong upper winds.

Overshooting Top - the storm has a vigorous updraft.  Persistent (more than 10 minutes) overshooting tops indicate updraft strong enough to produce severe weather.

Most of the mid-level features are associated with the storm's main updraft tower.  If the clouds in the updraft tower are sharply outlined with a distinct cauliflower appearance, then the storm has a strong updraft which may produce severe weather.

Flanking Line - thunderstorms with good storm-scale organization typically have a series of smaller cloud towers to the south or southwest of the main storm tower.  These smaller towers usually have a stair-step appearance as they build towards the main tower.

Striations - are streaks of cloud material that give the storm tower a "corkscrew" or "Barber pole" appearance  and strongly suggest rotation

Mid-Level Cloud Band - a ring of cloud material about halfway up the updraft tower encircling the tower like ring around a planet.  This is another sign of possible rotation.

As a storm grows in size and intensity, it will begin to dominate its local environment.  If cumulus clouds and other storms of interest dissipate, it may be a sign that the storm is taking control of the local area.

Rain-Free Base - the flat, smooth cloud base beneath the main storm tower from which or no precipitation falls.  The rain-free base is usually to the rear (south or southwest) of the precipitation area.  This marks the area of INFLOW.

Inflow Bands - ragged bands of cumulus clouds that extend from the main storm tower to the southeast or south and suggest the gathering of low-level air from several miles away.

Tail Cloud (Beaver's Tail) - a smooth, flat cloud band that extends from the eastern edge of the rain-free base into the rain-base.

• Suggests inflow/updraft

• Attached to rain-free cloud base

• Maintains position with respect to rain

• May contain a tail cloud that slopes upward from precipitation into storm

• Suggests downdraft/outflow

• Leading edge of gust front, moving away from rain

• Slopes downward away from the precipitation area

• Often associated with a squall line

• Funnel clouds rotate, usually rapidly, extending downward from the cloud base

• As opposed to scud clouds, funnel clouds typically have laminar or smooth appearance

• Funnel clouds are located near the updraft, usually vertical and several orders of magnitude smaller than parent wall cloud

• Tail clouds (Beaver's Tail) are often horizontal and funnel-like, but do not rotate; they should not be confused with actual funnel clouds for these reasons.  Beaver's clouds extent from the updraft tower into the rain0free base.

A local region of clearing skies or reduced cloud cover, indicating an intrusion of drier air; often seen as a bright area with higher cloud bases on the west or southwest side of a wall cloud.  A clear slot is believed to be a visual indication of a rear flank downdraft (RFD) and RFD may contribute to the formation of tornadoes.

• Wall clouds and tornadoes are typically on the right or front side of storm with respect to their movement.  This makes knowledge of storm motion important!

• The safest and best viewing angle is with the storm moving to your right as you look at it (Right Hand Rule)

• Viewing on the left or rear flank of the storm or with the storm moving to your left, often results in poor viewing with the line of sight obscured by rain and/or hail

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