pressure systems low pressure: an area where the atmospheric pressure is lower than the surrounding...
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Pressure Systems and Weather Fronts
Pressure SystemsLow pressure: an area where the
atmospheric pressure is lower than the surrounding areaAir rises then it cools and condensesWeather: cloudy and rainy
Pressure SystemsHigh pressure: an area where the
atmospheric pressure is higher than the surrounding areasAir is sinking Weather: light winds, dry, clear skies
High vs. Low pressure air movement LOW PRESSURE HIGH PRESSURE
Warm FrontWarm air mass moves into
a cold air massWeather: overcast or rain http://www.phschool.com/atschool/
phsciexp/active_art/weather_fronts/index.html
Cold FrontCold air mass gets pushed into warm air massWeather: Abrupt weather changes http://www.classzone.com/books/earth_science/terc/content/
visualizations/es2002/es2002page01.cfm?chapter_no=visualizatione
Occluded FrontsA warm air mass is caught
between 2 colder air masses
Weather: Severe storms
Stationary FrontWarm and cold air mass meet but neither has
greater force behind it to move the other mass
Weather: Fog, clouds, rain, snow
Severe WeatherThunderstorm: rain, hail, wind and lightning
Formation: rapidly rising air, warm or cold front
Lightning: small ice crystals that are positively charged collide with large ice crystals that are negatively charged
Tornado: a violently rotating column of air extending from a thunderstorm cloud
Severe WeatherCyclone: a tropical storm that is a low
pressure region surrounded by spiral thunderstorms that produces heavy rain and strong winds
Hurricane: a tropical cyclone that forms in the southern Atlantic, Caribbean Sea or the Gulf of Mexico
Severe WeatherBlizzard: a severe snow storm characterized
by strong winds and heavy snowfallDrought: an extended period of time when a
region does not receive rainfallFlash Flooding: rapid flooding caused by
heavy rainfall or rapid snow and ice melt
Severe WeatherEl Nino: The abnormal warming of the Pacific
OceanCauses: droughts in Asia, Flooding in Americas
La Nina: The abnormal cooling of the Pacific OceanCauses: flooding in Asia, Droughts in Americas
Severe WeatherMonsoon Wind: a change in the direction of
the wind due to abnormal heating of the surface of Earth
Monsoon Rain: a rainy season that can last for months caused by the change in wind direction