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Meteorology

They occur as a dense line along a front. Most common in the summer but rare

in Europe, and they are not as strong as other types of thunderstorms.

Because the CB cloud is hidden in the warm front's NS layer, it cannot be seen,

making it impossible to avoid.

3.9.4.5 Cold front thunderstorms

Cold front thunderstorms form

along a cold front.

They can occur at any time of day,

but are strongest in the afternoon

due to solar heating.

If you have to pass through a cold

front, it is important to pass it

perpendicular to the front to avoid

thunderstorm showers.

3.9.4.6 Squall-Line thunderstorms

Squall-line thunderstorms are the most severe form of thunderstorms. Squall

lines typically form in the afternoon and die down in the evening.

Here is a diagram of a squall

line

For a squall line, SIGMETs are

always issued

3.9.4.7 Thunderstorm warnings

When thunderstorms are expected or reported, a SIGMET (meteorological

message issued for significant weather) can be issued.

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 329