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Dec.20,2018 You need: Clean paper / pencil
HW: What did you learn from the BrainPop? 3rd period: What will happen to Little Rock and to Nashville? Warm Up: If we talk about a cold front, what symbol do we use? Which air mass is “winning”? I CAN: determine cloud types and storm categories Dec.20,2018
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Water in the Atmosphere
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Water Cycle The movement of water between the atmosphere and earth’s surface is the water cycle.
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How does water get into the air?
EVAPORATION – is the process where liquid water molecules escape into the air as water vapor. 3 things affect how quickly water evaporates: 1) Temperature 2) Wind 3) Humidity of the air
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How much water can air hold?
HUMIDITY is the measure of how much water vapor is in the air. TEMPERATURE affects how much water vapor the air can hold… Warm Air Cold Air holds MORE water vapor. holds LESS water vapor. That’s why air feels more “HUMID” on hot days!
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What is the “Dew Point”? As air cools, the amount of water vapor it can hold decreases. At a certain temperature, the water vapor in the air will CONDENSE back into water droplets or ice. This temperature is the “DEW POINT”.
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Climate vs Weather Global vs Local winds
LARGE scale = overall pattern, trend small scale = daily, weekly, small times Global vs Local winds LARGE scale = Over the entire Earth small scale = tiny area…usually land beside water.
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Global winds 1 2 3 4 5 Polar easterlies Prevailing westerlies
Horse latitudes 4 Trade winds 5 Equator / Doldrums
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Coriolis Effect – the effect on the air caused by the rotation of the earth.
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United States of America
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Air Masses & Fronts
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What is an AIR MASS? WARM COLD WET DRY
An air mass is a huge body of air that influences weather. Scientists classify air masses based on: TEMPERATURE and HUMIDITY WARM COLD WET DRY
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Air Masses are named based on where they FORMED…
= TROPICAL = POLAR = MARITIME (means sea… wet) = CONTINENTAL (means land… dry) WARM COLD WET DRY
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North American Air Masses
MARITIME POLAR CONTINENTAL POLAR MARITIME POLAR MARITIME TROPICAL MARITIME TROPICAL CONTINENTAL TROPICAL
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How do these air masses move?
MARITIME POLAR CONTINENTAL POLAR MARITIME POLAR Jet Stream That’s why weather generally moves WEST to EAST in the U.S. Jet Stream Prevailing Westerlies Prevailing Westerlies MARITIME TROPICAL MARITIME TROPICAL CONTINENTAL TROPICAL
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What happens when air masses meet?
Air masses don’t mix easily. The line between air masses is called a front.
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COLD FRONTS
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WARM FRONTS
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Watch the BrainPop video on “Weather” and write down 2 things you learned.
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Compare/Contrast Chart - Types of Fronts
How it Forms Type of Weather Cold A fast-moving cold air mass overtakes a warm air mass. Clouds form. If warm air is humid, rain/snow may fall. Possible thunderstorms. Warm Front A warm air mass overtakes a slow-moving cold air mass. Scattered clouds. Light rain or snow. May last several days. Stationary Front Cold and warm air meet, but neither can move the other. Creates “standoff” Rain, snow, clouds, or fog that may last for days. Occluded Front A warm air mass is caught between 2 cooler air masses. Warm air mass is pushed up. Temperature gets cooler. Clouds and rain may form.
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Surface Map (Fronts & Precipitation)
Warm Front H High Pressure Occluded Front L Low Pressure Cold Front Stationary Front
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Temperature Map
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H L What will happen to the weather in Little Rock?
Which direction is the warm front moving? L H 12°C 19°C 14°C 20°C 25°C Tuesday Weather Little Rock, AR Clouds & Rain Warmer = 21°C Wednesday Weather Little Rock, AR Partly Sunny Warmer = 26°C Monday Weather Little Rock, AR Sun & clear skies Cool = 15°C 28°C 21°C 26°C 15°C 30°C Warm Front H High Pressure Occluded Front L Low Pressure Cold Front Stationary Front
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Which direction is the cold front moving?
What will happen to the weather in Nashville? 10°C 8°C 18°C 10°C 11°C Thursday Weather Nashville, TN Partly Sunny Warm = 20°C Saturday Weather Nashville, TN Sunny Cool = 10°C Friday Weather Nashville, TN Thunderstorms Cooler = 15°C 10°C 20°C 15°C Warm Front H High Pressure Occluded Front L Low Pressure Cold Front Stationary Front
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BrainPop Yesterday! Log in: carrington1 Password: cougars
Watch the WEATHER video and write what you learn. Watch WIND, HUMIDITY, CLOUDS – video for each. Write two things you learn from each. Yesterday!
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Clouds Log in: carrington1 Password: cougars
Watch CLOUDS video. Write two things you learn from the video. Create your foldable.
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Storms
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