Lifting
•In cool season (late fall, winter, and
early spring), lifting occurs along boundaries between air masses è fronts
•When fronts are more distinct, very long
lines of thunderstorms can develop along frontal boundaries è frontal
squall lines.
•In warm season (late spring, summer,
early fall), lifting can be provide by less distinct boundaries, such as the
leading edge of a cool air outflow coming from a dying thunderstorm.
•Thunderstorms developed along these subtle
boundaries in the warm season often undergo a self-organized process
and lead to the a kind of severe storm called “mesoscale convective system” (MCS).
•“Meso-scale” refers to atmospheric
processes that occurs on a scale of a few hundreds hundreds
kilometers.