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Chapter 3.2 World Geography
Weather Factors
Pg. 46
Precipitation

Process that changes water from a liquid to
a gas is evaporation.
 Most water vapor that becomes rain is
evaporated from the oceans.
 The amount of water vapor in the air is
called humidity.
 The higher the temperature the more water
vapor the air can hold.
continued

When the air cools, it cannot hold the
amount of water vapor and condensation
occurs. Condensation is when water vapor
changes from a gas into liquid droplets.
 Clouds, dew, fog, or frost.
 May fall as rain.
Elevation and Mountain
Effects

High Elevation affects weather and climate.
 Increase in elevation – height on Earth’s
surface above sea level – causes a drop in
temperature.
 Orographic effect – occurs when moist air
pushes against a mountain, forces the air to
rise. This cools and condenses the air
resulting in precipitation.
continued

The side facing the wind received a lot of
rain fall.
 The other side (leeward) receives little to no
rain fall. This is known as the rain shadow.
 Deserts are located in these areas.
Storms

Sudden weather events. Cause high winds,
flooding, snow, lightning and turbulent seas.
 Middle latitude storms occur along polar
fronts. From when cold dry polar air mixes
with moist warm air from the tropics.
 Produce thunderstorms and tornados.
Thunderstorm
Continued
Tropical storms differ from middle –latitude
storms.
 Hurricanes are the most powerful and
destructive tropical cyclones.
 Bring heavy rain, and winds higher than
155 miles per hour.
 Known as typhoons in the western Pacific.

Hurricane
Weather Satellites
Because of Satellites – areas are given
warning of upcoming storms.
 Satellites carry special cameras that make
use of both visible light and invisible
infrared light.
