The type of cloud from which thunderstorms and heavy rain are experienced in the Tropics is

Step 1: Analyze the question The question asks which cloud type produces thunderstorms and heavy rain in the Tropics. So we need a cloud with great vertical development, strong convection, and large amounts of moisture.

Step 2: Concept: cloud types

• Altostratus (A): A grey, sheet-like middle-level cloud. It may bring light, steady rain or drizzle, but not thunderstorms.
• Cirrus (B): A thin, wispy, high-level cloud made of ice crystals. It gives no rain and usually signals fair weather, or an approaching change in weather.
• Cumulus (C): A white, fluffy, heaped cloud. Fair-weather cumulus gives little or no rain. It can grow into a rain-bearing cloud, but on its own it does not usually cause thunderstorms.
• Cumulo-nimbus (D): A massive, towering, anvil-topped cloud that can reach 10-15 km in height. It forms through intense convection in hot, humid conditions. It produces lightning, thunder, heavy downpours, and sometimes hail.

Step 3: Apply to the Tropics In the Tropics (including Nigeria), strong daytime heating causes air to rise rapidly (convectional rainfall). The rising moist air cools and condenses, forming huge cumulo-nimbus clouds. These give the short, intense afternoon thunderstorms we often see, especially at the start and end of the rainy season.

Step 4: Answer The correct option is D. cumulo-nimbus.

Exam tip: The word "nimbus" means rain. Whenever you see "nimbus" in a cloud name (cumulo-nimbus or nimbo-stratus), think rain. Add "cumulo" (heaped, towering) and you get thunderstorms. Remember: "Cumulo-nimbus = Cloud of Thunder."