This is terminology used by
storm chasers which indicates the area of the most intense
storm activity in a severe
thunderstorm which should be avoided if possible. The bear's cage is usually
northeast of the
mesocyclone region where the
tornado can be found. Dangers in the bear's cage include intense
lightning,
downburst winds,
flash floods, giant
hail, and intense
rainfall.
Storm chasers tend to approach a tornado from the southern side of the supercell where the weather is calmer.