Weather

Weather Weather refers to the state of the atmosphere at a specific time and place. Weather refers to the state of the atmosphere at a specific time and place. The one thing that you can talk to anybody about The one thing that you can talk to anybody about If you don’t like the weather in Texas just wait around it will change If you don’t like the weather in Texas just wait around it will change

Weather Components temperature, wind, clouds, humidity and precipitation, air pressure and air masses temperature, wind, clouds, humidity and precipitation, air pressure and air masses List the component and tell what it is and how it affects the weather on a daily basis List the component and tell what it is and how it affects the weather on a daily basis

Temperature Temperature is a measure of the energy of air molecules Temperature is a measure of the energy of air molecules High temperature means fast movement, low temperature means slower movement High temperature means fast movement, low temperature means slower movement

Wind Wind is air moving in a specific direction Wind is air moving in a specific direction As the Sun warms the air it expands and becomes less dense and low pressure. As the Sun warms the air it expands and becomes less dense and low pressure. Cooler air is more dense and sinks with higher pressure Cooler air is more dense and sinks with higher pressure Wind results because air moves from high pressure to low pressure (cool to warm) Wind results because air moves from high pressure to low pressure (cool to warm)

Wind Measurement Wind can be measured with a tool called an anemometer Wind can be measured with a tool called an anemometer

Clouds A visible body of water droplets or ice particles suspended in the atmosphere A visible body of water droplets or ice particles suspended in the atmosphere

Cloud Classification

Precipitation Water that falls from the clouds Water that falls from the clouds Air temperature determines the form of precipitation that falls Air temperature determines the form of precipitation that falls 4 main types of Precipitation: Rain, Sleet, Snow and Hail 4 main types of Precipitation: Rain, Sleet, Snow and Hail

Types ofPrecipitation Types of Precipitation Rain Sleet Snow Hail

Humidity Humidity is the amount of water vapor present in the air Humidity is the amount of water vapor present in the air Warmer air contains more water vapor than cooler air Warmer air contains more water vapor than cooler air Which has more water vapor? Which has more water vapor?

Humidity cont’d Relative humidity is the measure of the amount of water vapor present compared to the amount needed for saturation Relative humidity is the measure of the amount of water vapor present compared to the amount needed for saturation Dew point is the temperature at which the air is saturated and condensation forms Dew point is the temperature at which the air is saturated and condensation forms The closer the temperature is to the dew point, the more humidity there is The closer the temperature is to the dew point, the more humidity there is

Humidity Measurement Humidity can be measured with a tool called a psychrometer Humidity can be measured with a tool called a psychrometer

Pressure and Air Masses An air mass is a large body of air that has properties similar to where it developed An air mass is a large body of air that has properties similar to where it developed For example, one that forms over land will be dry. One that forms in the tropics will be warm For example, one that forms over land will be dry. One that forms in the tropics will be warm As these air masses move, weather changes occur As these air masses move, weather changes occur High pressure systems are usually fair and dry High pressure systems are usually fair and dry Low pressure systems are usually cloudy and wet Low pressure systems are usually cloudy and wet

Worldwide Air Mass Map c=continental m=maritime p=polar t=tropical e=equatorial

Isobars Lines that connect areas of equal pressure Sketch this picture

Fronts A front is a boundary between two air masses of different density, moisture or temperature A front is a boundary between two air masses of different density, moisture or temperature Cold fronts occur when cold air moves towards warm air. They usually bring thunderstorms Cold fronts occur when cold air moves towards warm air. They usually bring thunderstorms

Front’s Cont’d Warm fronts form when warmer air moves over colder air. These usually form hours or days of wet weather Warm fronts form when warmer air moves over colder air. These usually form hours or days of wet weather

Fronts Cont’d Stationary fronts occur when the boundary between two fronts stops advancing. They may remain in place for several days Stationary fronts occur when the boundary between two fronts stops advancing. They may remain in place for several days