Four Cloud Types Study Guide WEATHER TERMS Weather Tools CIRRUS Weather (SOL 4.6) Grade 4 Created by Jennie M. Carr – Rockingham County Public Schools – 2010 Revised by J. Segerson and J. Copeland – Loudoun County Public Schools - 2010 WEATHER TERMS Temperature - The measure of the amount of heat energy in the atmosphere. It is measured in degrees Celsius or Fahrenheit Air Pressure - The weight of the air, which is determined by several factors including the temperature. Low pressure signals stormy weather Wind: the movement of air. Wind Speed is how fast the wind is blowing. It is measured in miles per hour. Air moves from an area of HIGH pressure to an area of LOW pressure Precipitation - The amount of water, which falls from the sky. Can be in the form of snow, sleet, hail or rain. Collects in clouds Humidity – The amount of moisture or water vapor in the air. HIGH humidity means a greater chance of precipitation Weather Tools Thermometer measures Temperature Barometer measures Air Pressure Anemometer measures Wind Speed Rain Gauge measures Precipitation Wind Vane measures Wind Direction Hygrometer measures Humidity Low Pressure: usually brings clouds, rain, and wind; formed when air is warmed. High Pressure: usually brings dry, clear conditions; formed when air is cooled. BE ABLE to identify and explain the steps of the Water Cycle CIRRUS . CUMULONIMBUS Dark, tall, billowing cloud that produces rain and thunderstorms. Most common high cloud. Thin, feathery , wispy clouds Associated with fair weather Four Cloud Types STRATUS Gray, smooth cloud, sheetlike Covers whole sky blocks all sunlight. Light rain or drizzle usually occur. FOG is example CUMULUS White, fluffy cloud, cottonball Flat bottom that rises up. Usually indicating fair weather.

A dark, tall, billowing cloud that produces rain and thunderstorms. Study Guide Weather (SOL 4.6) Grade 4 Created by Jennie M. Carr – Rockingham County Public Schools – 2010 Revised by J. Segerson and J. Copeland – Loudoun County Public Schools - 2010 WEATHER TERMS Temperature - The measure of the amount of heat energy in the atmosphere. Air Pressure - The weight of the air, which is determined by several factors including the temperature. Wind Speed – How fast the wind is blowing. Precipitation - The amount of water, which falls from the sky. Wind Direction - The direction in which the wind blows. Humidity – The amount of moisture in the air. Weather Tools Thermometer measures Temperature Barometer measures Air Pressure Anemometer measures Wind Speed Rain Gauge measures Precipitation Wind Vane measures Wind Direction Hygrometer measures Humidity F R O N T Air Mass Air Mass A meteorologist uses weather instruments and data to predict weather patterns. A front is a boundary between air masses of different temperature and humidity. A cold front is formed when a cold air mass pushes into a warm air mass; may produce thunderstorms. A warm front is formed when a warm air mass pushes into a cold air mass; may produce light rain. Different atmospheric conditions produce the four types of precipitation: rain, snow, sleet, and hail. Low Pressure: usually brings clouds, rain, and wind; formed when air is warmed. High Pressure: usually brings dry, clear conditions; formed when air is cooled. CIRRUS A feathery cloud, usually associated with fair weather, but often indicates rain or snowfall in several hours. Four Cloud Types CUMULONIMBUS A dark, tall, billowing cloud that produces rain and thunderstorms. STRATUS A gray, smooth cloud that covers the whole sky and blocks all sunlight. Light rain and drizzle usually occur. CUMULUS A white, fluffy cloud with a flat bottom usually indicating fair weather. EXTREME atmospheric conditions create a variety of storms: Thunderstorm: A common storm with winds, rain, thunder, and lightning. Hurricane: A storm which forms over water with heavy winds. Tornado: A violent storm with a rotating column of air.