Moisture in the Air MOISTURE IN THE AIR

Weather Present state of the atmosphere and current conditions

Climate Weather over a long period of time Example: Subtropical, desert, etc….

Factors that influence weather Temperature Amount of moisture in air Air pressure Wind

Water Cycle

Precipitation Falling water out of sky Water droplets stay small will stay suspended in clouds When water droplets reach > 0.2 mm they fall out of sky as precipiation

Types of precipitation Rain, snow, sleet, and hail Air temperature determines what will fall out of sky Above freezing (32 o F) = rain Below freezing = snow Water freezes as ice = hail Snow, then melts, then refreezes = sleet

Snow

Sleet

Freezing Rain

Humidity Amount of water in the air Depends on temperature – High temp. – more water air can hold – Low temp – less water air can hold – CHANGES IN HUMIDITY INDICATE CHANGES IN WEATHER

Relative Humidity Measure of amount of water vapor in air compared to total amount of water vapor it has room for at a particular temperature Stated as a percent Example: 50 % humidity – air is only holding 50% of the water vapor that it can hold

Saturation When air is holding all the moisture it can at a particular temperature Saturated air = 100% humidity

Dew point Temperature at which air is saturated and condensation takes place.

Clouds Made of millions of water droplets Form as humid air is cooled and reaches its dew point and condenses Condensed water vapor forms tiny drops of water around dust particles in atmosphere Millions get together = cloud

Clouds are classified into a system that uses Latin words to describe the appearance of clouds as seen by an observer on the ground. Latin Root TranslationExample cumulus stratus cirrus nimbus heap layer curl of hair rain fair weather cumulus altostratus cirrus cumulonimbus

Clouds: Five Types of Clouds 1. High-Level Clouds: Usually found at greater than 20,000 ft. Usually made of ice crystals Examples include Cirrus, Cirrostratus

Clouds: Five Types of Clouds 2. Mid-Level Clouds: Usually found between 6,500 and 20,000 ft. Usually made of water droplets, but can be made of ice Example is altocumulus

Clouds: Five Types of Clouds 3. Low-Level Clouds: Usually found lower than 6,500 ft. Low, lumpy clouds that produce weak to moderate precipitation Examples include Nimbostratus and Stratocumulus

NSF North MississippK-8 Clouds: Five Types of Clouds 4. Vertically developed: These clouds are thick and puffy and extend very far upwards Examples include Cumulonimbus and Fair Weather Cumulus Ordinary Cumulus clouds can quickly become Cumulonimbus clouds that start strong thunderstorms

Clouds: Five Types of Clouds 5. Other: These are miscellaneous clouds These clouds do not really fit into any category, and all have different characteristics Examples include billow clouds, contrails, mammatus, orographic, and pileus