Question 1 of 15
What is a puffy fair-weather cloud called?
Why: Cumulus clouds look like cotton balls in blue sky.
Question 2 of 15
What high, wispy cloud is made entirely of ice?
Why: Cirrus clouds form above 20,000 feet where temps are below freezing.
Question 3 of 15
What cloud type produces thunderstorms?
Why: The 'nimbus' part means 'precipitating'.
Question 4 of 15
What is virga?
Why: Virga looks like streaks hanging beneath a cloud that never reach the ground.
Question 5 of 15
What are mammatus clouds?
Why: They form on the underside of a thunderstorm anvil after severe weather.
Question 6 of 15
What lens-shaped cloud forms above mountains?
Why: Lenticular clouds form in standing waves of air over ridges.
Question 7 of 15
What creates a rainbow?
Why: Sunlight enters a droplet, reflects off the back, and refracts on exit.
Question 8 of 15
What creates a double rainbow?
Why: The secondary bow forms from light that reflects twice inside droplets.
Question 9 of 15
What is a 'wall cloud'?
Why: Wall clouds often precede tornado formation.
Question 10 of 15
What is a shelf cloud?
Why: Shelf clouds mark the leading edge of a storm's cool outflow.
Question 11 of 15
What is a roll cloud?
Why: Roll clouds are detached from the parent storm, unlike shelf clouds.
Question 12 of 15
What color scatters most in the atmosphere, giving the sky its color?
Why: Blue light scatters more (Rayleigh scattering); violet scatters even more but our eyes are less sensitive to it.
Question 13 of 15
What is a halo around the sun or moon caused by?
Why: Cirrus ice crystals refract light at 22°, forming a ring.
Question 14 of 15
What is fog?
Why: Fog is essentially a stratus cloud at ground level.
Question 15 of 15
What are noctilucent clouds?
Why: Noctilucent clouds glow at high latitudes in summer twilight.