A pilot with airborne weather radar should remember that radar does not eliminate the hazards of
the thunderstorm. It merely helps to locate the most severe conditions. Since the radarscope
indicates only precipitation areas within thunderstorms, hazards can be encountered even in soft
spots. Thunderstorms having frequent, vivid lightning discharges are especially dangerous.
Airborne weather radar should be used as an avoidance rather than penetration tool. The pilot
should take time to properly evaluate scope indications and watch for trends in order to avoid the
most intense echo patterns. The pilot without airborne weather radar should make no attempt to
find soft spots on the basis of radar information not current up-to-the-minute.
FLIGHT TECHNIQUES IN THE VICINITY OF THUNDERSTORMS
Since thunderstorms have so many potential hazards, it is appropriate to list some recommended
practices for pilots who must cope with these "uninvited guests." As far as flying is concerned,
there is no such thing as a small thunderstorm, so some common sense recommendations are
If at all possible, avoid thunderstorms.
Do not venture closer than 20 miles to any storm cloud with overhanging anvils because of
the possibility of encountering hail.
Do not attempt to fly under thunderstorms in mountainous regions even if the area on the
other side of the mountains can be seen. Strong enough winds providing the lifting action to
produce the thunderstorms can also create extreme turbulence between mountain peaks.
If at all possible, avoid flying under thunderstorms because updrafts and downdrafts can
exceed the performance of the aircraft.
Do not take off or land if a thunderstorm is approaching. Sudden wind shifts or
microbursts can cause control problems.
Do not fly into a cloud mass containing scattered embedded thunderstorm without airborne
radar. Radar is necessary to "see" storms in the cloud mass. Scattered thunderstorms can be
circumnavigated visually unless they are embedded.
developed or dissipated thunderstorm. Aircraft should also avoid clouds downwind of
The brighter and more frequent the lightning, the more severe the thunderstorm.
Regard any thunderstorm with tops 35,000 feet or higher as severe.
Avoid thunderstorms if at all possible using the following recommendations, listed in order of
Fly around (circumnavigate) the storm.
Fly over the top of the storm.