UNIT 4: WEATHER AND NATURAL DISASTERS

Severe Weather

UNIT 4: WEATHER AND NATURAL DISASTERS

Part 1: Clouds and Precipitation

Unit Objectives Upon completion of the unit, TSWBAT:

1. Explain the causes behind natural disasters2. Read and interpret satellite images and map data3. Discuss how natural disasters affect humans as well as the environment4. Describe various types of weather

What is Weather? Weather is the state of the atmosphere at

any given time and place. Weather occurs all over the world all the

time. Weather is something that anybody can

talk about. Weather can be one extreme in one coast

of the country and another extreme on the opposite coast.

Air Temperature Air temperature (Also termed surface

temperature in meteorology). The ambient temperature indicated by a thermometer exposed to the air but sheltered from direct solar radiation.

Air temperature is measured by a thermometer.

What causes air temperature? The temperature of the air is caused by

the combination of air, water, and land working together. Those three factors heat and cool areas at different rates. Temperature also varies by the time of day, the season, or even the year.

Wind also affects air temperature. This is the movement of air in the atmosphere.

Humidity is also a factor in air temperature.

Humidity is the amount of water vapor present in the atmosphere.

Clouds Clouds are masses of small water

droplets or tiny ice crystals that float in the air.

Three main types are cirrus, cumulus, and stratus.

Other clouds are a mixture of these three main types.

How do clouds form?

Types of Clouds

Cirrocumulus Cirrostratus

Stratocumulus Cumulonimbus

Precipitation There are four main types of

precipitation: rain, sleet, snow, and hail.

Rain

Snow

Sleet

Hail

Air Masses A large body of air that has properties similar to

the part of the Earth’s surface over which it develops.

Air masses that “come together” form frontal boundaries.

These boundaries can cause severe weather such as hail, tornadoes, blizzards, and floods.

Air Mass Map

Weather Fronts

Tornadoes

Tornado Map