Honeywell Primus 880 Pilot's Manual page 149

PRIMUSr 880 Digital Weather Radar System
EXTRAPOLATION TO DIFFERENT CLIMBS
General comment: Severe storms are associated with an atmospheric
stratification marked by large values of moisture in low levels, relative
dryness in middle levels, and strong wind shear. It is well known that
this stratification of moisture permits excessive magnitudes of
convective instability to exist for an indefinite period until rapid
overturning of air is triggered by a suitable disturbance. Regions of the
atmosphere which are either very dry or very moist throughout
substantial depths cannot harbor great convective instability. Rather,
a more nearly neutral thermal stratification is maintained, partially
through a process of regular atmospheric overturning.
Desert Areas - In desert areas, storms should be avoided on the
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same basis as described in the above paragraphs. While nonstorm
turbulence may, in general, be expected more frequently over desert
areas during daylight hours than elsewhere, THE SAME
TURBULENCE CONSIDERATIONS PREVAIL IN THE VICINITY
OF THUNDERSTORMS.
Tropical- Humid Climates - When the atmosphere is moist and only
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slightly unstable though a great depth, strong radar echoes may be
received from towering clouds which do not contain vertical velocities
as strong as those from storms over the U.S. plains. Then it is a matter
of the pilot being informed with respect to the general atmospheric
conditions accompanying storms, for it is well known that
PRACTICALLY
THUNDERSTORMS ARE OCCASIONALLY VISITED BY SEVERE
ONES.
USE OF AIRBORNE RADAR
Airborne radar is a valuable tool; HOWEVER, ITS USE IS
PRINCIPALLY AS AN INDICATOR OF STORM LOCATIONS FOR
AVOIDANCE PURPOSES WHILE ENROUTE.
Federal Aviation Administration (FAA) Advisory Circulars
A- 14
ALL GEOGRAPHIC AREAS HAVING
A28- 1146- 102- 00