Chapter 8Chapter 8 Section 3-5Section 3-5

(section 1-2 info is in your (section 1-2 info is in your Water Cycle Presentation)Water Cycle Presentation)

Section 3 Air Masses- Section 3 Air Masses- a huge a huge body of air that has similar body of air that has similar

temperature, humidity, and air temperature, humidity, and air pressure at a given height.pressure at a given height.

Types of air masses:Types of air masses:• Maritime TropicalMaritime Tropical• Maritime PolarMaritime Polar• Continental TropicalContinental Tropical• Continental PolarContinental PolarMaritime-over the ocean, Maritime-over the ocean,

humidhumidContinental-over land, low Continental-over land, low

humidityhumidityTropical-warmTropical-warmPolar-coldPolar-cold

How air masses move-How air masses move-• Prevailing Westerlies- Prevailing Westerlies-

major wind belt over major wind belt over US, usually west to US, usually west to east.east.

• Jet Streams- high speed Jet Streams- high speed air masses embedded air masses embedded in the westerlies.in the westerlies.

• Fronts- the boundary Fronts- the boundary where two air masses where two air masses meet.meet.

Types of FrontsTypes of Fronts• Cold fronts- cool, Cold fronts- cool,

dense airdense air

• Warm fronts- Warm fronts- warm, less dense warm, less dense airair

• Stationary fronts- Stationary fronts- when cold and when cold and warm air meet, warm air meet, neither one can neither one can movemove

• Occluded fronts- Occluded fronts- where a warm air where a warm air mass is caught mass is caught between two cold between two cold air massesair masses

Section 4 Storms!Section 4 Storms!• A violent disturbance in the atmosphere.A violent disturbance in the atmosphere.• Thunderstorms with heavy precipitation, including Thunderstorms with heavy precipitation, including

thunder, the sound of an explosion, and lightning, an thunder, the sound of an explosion, and lightning, an electrical charge.electrical charge.

• Tornadoes- a rapidly whirling, funnel-shaped cloud over Tornadoes- a rapidly whirling, funnel-shaped cloud over land that reaches down from a storm cloud to the earth.land that reaches down from a storm cloud to the earth.

• Snow storms- large amounts of precipitation in the form Snow storms- large amounts of precipitation in the form of snow.of snow.

• Hurricanes-tropical cyclone, which is a swirling center of Hurricanes-tropical cyclone, which is a swirling center of low air pressure, winds of 119 kph at least, begins over low air pressure, winds of 119 kph at least, begins over water, the “eye” of a hurricane is the calm inside the water, the “eye” of a hurricane is the calm inside the middle.middle.

• Floods- after a major downpour of rain, flash floods can Floods- after a major downpour of rain, flash floods can occur.occur.

Section 5 Predicting Section 5 Predicting WeatherWeatherMeteorologist- scientists who Meteorologist- scientists who

study the causes of study the causes of weather and try to predict weather and try to predict it. They use maps, charts it. They use maps, charts and computers to forecast and computers to forecast the weather.the weather.

Reading a weather map:Reading a weather map:Symbols, color for Symbols, color for

temperature and lines are temperature and lines are used to show the direction used to show the direction of winds, fronts, etc.of winds, fronts, etc.