Extremely heavy rainfall or high terrain can reduce the ability of the
radar to penetrate and present a full picture of the weather area. This is
called radar attenuation. Use MAP mode along with the weather
modes to identify areas of shadowing. Observe the ground returns in
the area behind the strong weather echo. With very heavy intervening
rain, the ground returns behind the echo will not be present but rather
will appear as a shadow. This may indicate a larger area of
precipitation than appears on the weather display.
apparent clear weather behind the
storm cells. If the MAP display shows
a shadow in this area, there may be
weather here that the radar cannot see.
Principles of Weather Radar Use
IntuVue RDR-4000 Weather Radar Pilot's Guide
Note the area of
Corresponding MAP display.
radar returns in the circled areas indicates
that terrain or very heavy rain in front of
those areas prevents the radar signal from
penetrating any farther.
Rev 1, December 2014
The lack of