Figure 4-14. Thunderstorm Penetration

AVIATION WEATHER

CHAPTER FOUR

severe in top 2/3 of the cell (Figure 4-13). However, with the strong updrafts and downdrafts,

adequate terrain clearance should also be considered in the selection of a penetration level.

When crossing a line of thunderstorms (a squall line for example), attempt to determine the

orientation of the line and penetrate the line at right angles (Figure 4-14). During the penetration

of a thunderstorm, do not attempt to turn back once you are inside the storm. Remember, single-

cell thunderstorms are only about one to five miles in diameter, and turning around will only

increase your time in the storm. Turning around can also result in a pilot becoming disoriented

and flying in the storm for a considerably longer period of time than continuing directly through

the storm in the first place. With no other information to make a decision, a penetration altitude

between 4000 and 6000 feet AGL should be adequate.

Figure 4-13 Through the Thunderstorm

Figure 4-14 Thunderstorm Penetration

Thunderstorms

4-15