Supercell Thunderstorms

Ø  Forward and rear flank downdrafts are rapping around the updraft which is occlusion

Ø  Occlusion (pg. 162 – Figure 9.7)

Ø  New updraft will form on the triple point of the occlusion

Ø  V-Notch

̶        Strong updraft

̶        Goes around the updraft

̶        Inflow notch

Ø  Beaver’s Tail

̶        Flat cloud that lines up on the forward flank gust front

̶        Connected to the rain free base

Ø  Tail Cloud

̶        Attached to wall cloud

Ø  SCUD – Scattered Cumulus Under Deck

̶        Cooler air from the forward flank is drawn into the storm and reaches saturation below the cloud’s LCL

̶        Often the wall will lean toward the precipitation

̶        Strong motions are often apparent to the spotter

Ø  HP (High Precipitation)

̶        These storms are difficult to spot for two primary reasons:

1.    Obscuration and misplacement of important features and safety. The best place to spot the tornado is usually in its path

2.    Originally, HP supercells were considered rare. In reality, perhaps half of all supercells are HP

̶        HP supercells are also prolific tornado producers, much more than originally thought.

̶        These are usually big and scary storms.

̶        Great deal more precipitation in the RFD with rain actually falling through the rain free base (not really a rain free base)

̶        2 reasons they are EASY to find

1.    Visual Vault

2.    Beaver’s Tail

̶        Beaver’s tail is INFLOW into the storm

Ø  LP (Low Precipitation)

̶        Storm without a rear flank downdraft

̶        These storms are easy to identify marked by light precipitation in the main downdraft

̶        LP’s tornadic potential is somewhat limited

̶        They do produce damaging hail and can change modes throughout their lifetime

̶        Prolific producers of large hail

̶        IF tornadoes do form the storm may be becoming more like a supercell