Published on

Published in: Education, Technology, Business
1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. Clouds and Precipitation Alyssa Goodwin
  2. 2. Adiabatic Temperature Changes and Expansion and cooling • When air is allowed to expand, it cools, and when it’s compressed, it warms. • Temperature changes that happen even though heat isn’t added or subtracted. It’s the result of compressed air. • Expansion and cooling happens because there are fewer and fewer gas molecules.http://apollo.lsc.vsc.edu/~wintelsw/MET1010LOL/chapter06/
  3. 3. Orographic Lifting• When elevated terrains act as barriers to air flow.• As air goes up a mountain slop, adiabatic cooling generates clouds and precipitation.• By the time air reaches the leeward side of a mountain, much of it’s moisture has been lost. https://fp.auburn.edu/fire/weather_elements.htm
  4. 4. Frontal Wedging• Warm and cold air collides• Cool, dense air act like a barrier then the warmer, less dense air rises.• Usually creates rain https://fp.auburn.edu/fire/weather_elements.htm
  5. 5. Convergence • When air in the lower atmosphere flows together. • Air goes up because it cant go down. • This leads to cloud formation.http://apollo.lsc.vsc.edu/classes/met130/notes/chapter6/lift_converge.html
  6. 6. Localized Convective Lifting • Unequal heating of the Earth’s Surface • The air above a warmer, dense area will rise • When warm parcels of air rise above condensation level, clouds form.http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/dvlp/cnvrg.rxml
  7. 7. Stability (Density Differences and Stability and weather) • Stable air remains in it’s original position, unstable air rises. • Stable air resists upward movement. • Clouds won’t form when stable air resists upward movement.http://www.santabarbara.com/community/weather/
  8. 8. Condensation • For any of these forms of condensation to occur, the air must be saturated. • It happens when water vapor changes to a liquid. • Saturation occurs mostly when air is cooled to its dew point or when water vapor is added to the air.http://shoalwater.nsw.gov.au/Education/condensation.htm
  9. 9. Types of Clouds • Clouds are classified by their form and height. • Cirrus-curl of hair, Cumulus-a pile, stratus-a layer. • All other clouds reflect one of these three basic form or are combinations or modifications of them.http://eo.ucar.edu/webweather/cloud3.html
  10. 10. High Clouds • Cirrus, Cirrostratus and Cirrocumulus. • High clouds are thin and white and often made up of ice crystals • Low temperatures and small quantities of water vapor are present at high altitudes.https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Ffire%252Fs290%252Funit6%252Fprint_2.htm
  11. 11. Middle Clouds • Clouds in the middle range have the prefix alto- as part of their name. • Altocumulus clouds are larger and denser that Cirrocumulus (high Cloud) • Middle clouds usually are accompanied by snow or drizzlehttps://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Ffire%252Fs290%252Funit6%252Fprint_2.htm
  12. 12. Low Clouds • Stratus, Stratocumulus, nimbostratus. • Look like fog-like layers and have vertical development. • Develop in stable air, because air is forced upward.https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Ffire%252Fs290%252Funit6%252Fprint_2.htm
  13. 13. Clouds of Vertical Development • Some clouds aren’t categorized by high, middle, or low, they extend upward. • Once upward movement is started, acceleration is powerful and clouds with a lot of vertical range form. • End result is cumulonimbus clouds and rain or thunderstorms.http://en.wikipedia.org/wiki/Cloud
  14. 14. Fog (by cooling and by evaporating) • Fog is defined as a cloud with its base at or very near the ground. • Form on cool, clear, calm nights when the surface is cooled rapidly by radiation. • Cool air moves over warm water, moisture might evaporate from the water surface to produce saturation.http://www.kidsgeo.com/geography-for-kids/0110-fog.php
  15. 15. Cold Cloud Precipitation (Bergeron Process) • Supercooling and supersaturation. • Supercooled air will freeze when it impacts a solid object. • Ice crystals can’t coexist with water droplets in air because the air “appears” supersaturated to the ice.http://www.geo.hunter.cuny.edu/~tbw/wc.notes/5.cond.precip/precipitation/bergeron_process.htm
  16. 16. Warm Cloud Precipitation (Collision-coalescence process) • Collision-coalescence process is a mechanism that forms raindrops. • As large droplets move through the cloud, they join with smaller, slower droplets. • The droplet become bigger from joining.https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Fhydro%252Fbasic_int%252Fflash_flood%252Fnavmenu.php%253Ftab%253D1%2526page%253D2.2.2
  17. 17. Rain and Snow • Rain means drops of water that fall from a cloud and have a diameter of at least .5 mm. • Surface temperature above 4°C, flakes melt. • At low temperatures, light and fluffy snow falls.http://zahiym5tlc.edublogs.org/
  18. 18. Sleet, Glaze, and Hail • Sleet-the fall of small particles of clear-to- translucent ice. • Glaze-known as freezing rain • Hail-produced in cumulonimbus clouds. They begin as small ice pellets that grow by collecting supercooled water droplets.http://www.kidsgeo.com/geography-for-kids/0119-hail.php