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Weather PowerPoint Presentation

Weather

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Weather

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Presentation Transcript

  1. Weather • The sun provides energy that drives the Earth’s weather. • The state of the atmosphere at a specific time and place • Conditions such as temperature, wind, air pressure, amount of moisture

  2. Temperature – measure of average amount of motion of molecules Fast = warm Slow =cool Air Temperature

  3. Air moving in a specific direction Speed is measured by an anemometer Direction by a wind vane or wind sock Wind

  4. The amount of water vapor in air Warmer air can have more water vapor than cooler air Cool air favors condensation Humidity

  5. Measure of the amount of water vapor compared to amount needed for saturation Increases with temp 50% RH means the air contains 50% of water needed for air to be saturated. Relative Humidity

  6. The temperature at which air is saturated and condensation forms Dew point changes with the amount of water vapor in the air Ex: water droplets on the outside of a glass of water Dew Point

  7. Clouds form as warm air is forced up, expands and cools. RH = 100% Water vapor condenses around small particles Water droplets collide and form a cloud Cloud Formation

  8. Classifying Clouds • Shape • Stratus = layers or smooth sheets • Fair weather, rain or snow • Cumulus = puffy, white w/ flat bases • Fair weather, thunderstorms • Cirrus = thin, white, feathery • Fair weather, approaching storms

  9. Classifying Clouds • Height • Cirro – high clouds • Alto – middle clouds • Strato - low clouds

  10. Precipitation • Water falling from clouds • Type of precipitation depends on air temperature • 4 types: • Rain • Snow • Sleet • Hail

  11. Hailstones

  12. Air Masses • A large body of air that has properties similar to the part of Earth’s surface over which it develops. • 6 air masses affect the US

  13. Anticyclone Clockwise Air moves out of Fair weather Cyclone Counterclockwise Air moves into Cloudy & rainy High Pressurevs.Low Pressure

  14. High Pressurevs.Low Pressure

  15. Boundary between 2 different air masses Clouds, precipitation, storms Fronts

  16. Types of Fronts

  17. Severe Weather • Thunderstorms • Tornadoes • Hurricanes • Blizzards

  18. Movement of air in a storm cloud causes oppositely charged regions which create a current: lightning Rapid expansion and contraction of superheated air causes thunder Thunderstorms

  19. A violently rotating column of air in contact with the ground Caused by winds of different speeds and directions Measured by Fujita Scale (F0 – F5) Tornadoes

  20. Large swirling low-pressure system that forms over the warm tropical Atlantic Hurricanes

  21. Hurricane Ike

  22. Hurricane Ike

  23. Blizzard • Wind speed of 56 km/hr • Low temperature • Visibility is less than 400 m in falling or blowing snow • 3 hours or longer