Mechanism of rainfall formation Precipitation that results from buoyant upward motion of warmer, lighter air parcels relative to surrounding air is called:

Introduction / Context:
Understanding the mechanisms that produce precipitation helps engineers interpret storm intensities used in design. Principal mechanisms include convective, orographic, and cyclonic (frontal) lifting.

Given Data / Assumptions:

• Air parcel is warmer and less dense than its surroundings.
• Upward motion is driven by positive buoyancy.

Concept / Approach:
Convective precipitation forms when surface heating creates unstable air that rises, cools adiabatically, and condenses. It is often intense and short-duration, typical of thunderstorms. Orographic precipitation arises from forced ascent over topography. Cyclonic precipitation is associated with fronts and large-scale ascent.

Step-by-Step Solution:

Verification / Alternative check:
Convective storms typically show high intensities used for urban drainage design (short time of concentration).

Why Other Options Are Wrong:

• (a) Cyclonic is frontal lifting, not buoyant thermals.
• (c) Orographic requires terrain-forced ascent.
• (d) Incorrect by elimination.
• (e) Not a standard term in this context.

Common Pitfalls:
Confusing convective showers with stratiform rain from fronts or upslope drizzle produced orographically.

Final Answer:
Convective precipitation