Download Weather Study Guide

Weather Study Guide
Clouds form when water condenses.
Know the main types of clouds.
Cumulus clouds are puffy clouds that look like cauliflower. They form when
large areas of warm, moist air float upward from Earth’s surface. These clouds appear in
sunny, summer skies.
Stratus clouds are low clouds that often bring drizzle. They are like flat gray
blankets that seem to cover the sky. Stratus clouds form when a flat layer of warm, moist
air rises very slowly.
Cirrus clouds look like commas in the sky. They are often a sign that rainy or
snowy weather is on its way. Cirrus clouds form when the air rises high enough for ice
crystals to form.
A weather forecaster is someone who makes predictions about the weather. To predict
the weather, a forecaster must consider the temperature, air pressure, cloud types,
humidity, wind speed, and wind direction.
An air mass is a body of air that has the same general temperature and air pressure
throughout.
A front is a place where two different types of air masses meet.
A cold front forms when a cold air mass moves into a warm air mass. Cold fronts often
produce thunderstorms.
A warm front forms when a warm air mass moves into a cold air mass. Warm fronts
often bring light rain.
A weather map shows many conditions of Earth’s air at a given time and place. A
forecaster studies the model, interprets the data, and then predicts the weather.
A thunderstorm is a storm that produces heavy rain, strong winds, lightning, and
thunder. You see lightning before you hear thunder because light travels faster than
sound.
Hurricanes are large, violent storms that form over warm ocean water.
A tornado is a funnel-shaped storm that occurs over land.
Know that fog is actually a cloud that forms near the ground.
Humidity is the amount of water vapor in the air.
High pressure areas are areas where pressure is higher than the surrounding air; air
particles are closer together than those in the surrounding air; cooler air has higher
pressure because its air particles are closer together.
Low pressure areas are areas where air pressure is lower than the surrounding air; air
particles are farther apart than those in the air around them; warm air has a lower pressure
because the air particles are farther apart.
Know the different weather instruments.
Barometer-a device used to measure air pressure; a dropping barometer reading
means that the air pressure is also dropping.
Wind vane-a device used to find wind direction
Wind sock-a cloth bag that is narrow at one end and open at both ends; air enters
the wide end and causes the narrow end to point in the direction that the wind is blowing.
Anemometer-a device used to measure wind speed.
Rain gauge-a device used to measure the amount of precipitation
Hygrometer-measures humidity (the amount of water vapor in the air)
Thermometer-measures the temperature (how hot or cold the air is)
Know the steps in the water cycle and be able to explain each step. (Evaporation,
condensation, precipitation, and accumulation)
Know weather symbols and what type of weather each brings. See class notes. Be
prepared to forecast the weather using a weather map.
Freezing point of water is 32 F or 0 C
Boiling point of water is 212 F or 100 C
Heat makes molecules expand.
Cold makes molecules contract.