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⚖ Weather · PHAK Chapter 12, Weather TheoryWX-020 · 123 of 261

What are the three stages of a thunderstorm cell in the correct sequence?

AFormation, active, and dissipating.
BCumulus, mature, and dissipating.
CBuilding, peak, and collapse.

Why →A thunderstorm progresses through: Cumulus Stage (strong updrafts, vertical development), Mature Stage (updrafts and downdrafts coexist and precipitation reaches the surface: the most hazardous phase, with lightning, hail, and wind shear), and Dissipating Stage (downdrafts dominate, updraft supply cut off, storm weakens).

The trap →"Formation, active, dissipating" is plausible-sounding but non-standard: the FAA terms are cumulus, mature, dissipating. And it is the mature stage, not a "peak," that is most dangerous.

Field note →Mature-stage updrafts can reach 6,000 fpm. The dissipating stage is still not flyable; it carries embedded lightning and hail. There is no safe stage of a thunderstorm for sUAS.

SOURCE → PHAK Chapter 12, Weather TheoryCHECKED JUL 16ACS III.B.K1MED