Module 8 precipitation Flashcards
Is dew considered a form of precipitation?
No, because it does not fall from a cloud.
What is the size range of cloud droplets?
10-20 µ (1/100 mm to 2/100 mm).
What happens when cloud droplets condense and stick together?
They grow larger and can eventually fall as rain.
How much larger are raindrops compared to cloud droplets?
10 to 1,000 times larger.
What is required for droplets to be classified as rain?
Droplets must be larger than 0.5 mm in diameter.
What is drizzle?
Precipitation made up of tiny water drops less than 0.5 mm in diameter.
What causes freezing rain?
Rain cools below freezing and freezes on contact with cold surfaces.
What is the danger posed by freezing rain?
It can create ice storms that damage trees and power lines.
What is sleet?
Rain that begins to freeze as it falls.
How does hail form?
Frozen raindrops are tossed around in thunder-type clouds, collecting layers of ice.
What is the minimum diameter for a hailstone?
More than 5 mm.
What is a snowflake?
A six-sided ice crystal formed when water vapor freezes.
What instrument is used to measure liquid precipitation?
A rain gauge.
How is solid precipitation like snow measured?
With a ruler or measuring stick.
What is orographic lifting?
The process where water vapor rises up a mountainside, cooling and condensing into rain.
What is the windward side of a mountain?
The side that receives more rain as the wind blows directly on it.
What causes the rainshadow effect?
The inability of clouds to pass over a mountain, leading to dry conditions on the leeward side.
What regions typically experience low precipitation due to sinking air?
The North Pole, South Pole, and the Sahara desert.
Fill in the blank: The primary cause of precipitation is the ______.
[evaporation, convection, and cooling of water vapor]
