Weather and Climate: Types of Clouds, Rainfall, and Winds

Geography Notes: Weather and Climate

1. Types of Clouds

Clouds are classified based on appearance and altitude:

A. High-Level Clouds (Above 6 km)

Cirrus (Ci): Wispy, feather-like, indicates fair weather but can signal a change.

Cirrostratus (Cs): Thin, sheet-like, often covers the sky, can cause halos around the sun or
moon.

Cirrocumulus (Cc): Small, white patches, ripple-like, indicate fair but cold weather.


B. Mid-Level Clouds (2–6 km)

Altostratus (As): Gray/blue, cover the sky, often bring continuous rain.

Altocumulus (Ac): White/gray, patchy, indicate unsettled weather.


C. Low-Level Clouds (Below 2 km)

Stratus (St): Gray, uniform layer, drizzle possible.

Stratocumulus (Sc): Lumpy, gray, may bring light rain.

Nimbostratus (Ns): Thick, dark, produce continuous rain or snow.


D. Clouds with Vertical Development

Cumulus (Cu): Fluffy, white, flat base, fair weather.

Cumulonimbus (Cb): Towering, thunderstorm clouds, heavy rain, lightning, hail.


2. Rainfall Formation

Rainfall occurs when water vapor condenses and falls to the ground. Main types:

A. Convectional Rainfall