This document discusses various meteorological concepts related to cloud formation and precipitation. It covers topics like adiabatic temperature changes, orographic lifting, frontal wedging, convergence, stability, condensation, different cloud types classified by height and form, fog, precipitation processes in warm and cold clouds, and types of precipitation including rain, snow, sleet, glaze and hail. Each section provides a brief definition or explanation of the term and includes a link to an external reference site for more information.

1. By: Courtney Smith

2. arm.html
Adiabatic Temperature Changes
and Expansion and Cooling
 Temperature changes that happen even though heat isn’t added or subtracted
from the atmosphere are adiabatic temperature changes.
 Air that is not saturated cools 10 degrees Celsius for every 1000 meters it goes is
the dry adiabatic rate.
 Wet adiabatic cooling is when air rises and condensation begins to happen,
then latent heat in water vapor from condensation is released.
 http://apollo.lsc.vsc.edu/classes/met130/notes/chapter6/adiab_warm.html


3. Orographic Lifting
 When land masses, such as mountains, block air flow, orographic lifting of the
air happens.
 Clouds and precipitation occur due to adiabatic cooling and cause
precipitation.
 Much of the air’s humidity is lost when air reaches the leeward side of the
mountain.
 http://www.examiner.com/outdoorsman-in-salt-lake-city/understanding-why-
utah-has-the-greatest-snow-on-earth-part-1-orographic-lifting

4. Frontal Wedging
 A front is when hot air and cold air meet in the atmosphere.
 Frontal wedging is when cool and dense air barriers warm and less
dense air that is rising.
 Storm-system weather fronts are also known as middle latitude
cyclones.
 http://www.wou.edu/las/physci/taylor/gs106/atm2_precip_files/frame.
htm#slide0004.htm

5. Convergence
 Convergence is when air in the lower part of the atmosphere flows together and
causes lifting.
 Florida’s weather is an example of convergence.
 When air flows in more than one direction, it begins to rise. It leads to
adiabatic cooling and sometimes cloud formation.

6. Localized Convective Lifting
 Thermals: Rising clumps of air warmer than the air around it.
 Localized Convective Lifting: The process that makes the rising thermals.
 Clouds can form when the warm air clumps rise above the condensation level.
 http://rst.gsfc.nasa.gov/Sect14/Sect14_1c.html

7. Stability
 Stable air resists moving upward.
 Unstable air rises as stable air stays in the same place.
 When air increases with height, air is the most stable.
This is a temperature inversion.

8. Condensation
 Air must be saturated for condensation to happen.
 Condensation nuclei occur when there is condensation
in the air above the ground.
 When condensation nuclei is in the air, relative
humidity goes over 100%
 http://keep3.sjfc.edu/students/kes00898/e-port/condensation%20page%20for%20unit.html

9. Types of Clouds
 Clouds are classified by form and height.
 Cirrus clouds are thin, white, and high in the air.
 Cumulounds clouds are round, individual clouds.
Stratus clouds are big clouds that cover almost the
whole sky.
 http://eo.ucar.edu/webweather/cloud3.html

10. High Clouds
 Cirrocumulous clouds are fluffy clouds.
 Cirrostratus clouds are flatter clouds.
 Cirrus clounds are high, white, and thin clouds.

11. Middle Clouds
 Altocumulouds clouds are large, dense, and round clouds.
 Altostratus clouds are white and grayish clouds that cover the
sky, moon, and sun but they are still noticeable through it.
 Middle clouds are from 2000 to 6000 meters in the air.
 http://www.allstar.fiu.edu/aero/fltenv3.htm

12. Clouds of Verticle Development
 Most start in the low range but are vertically long and
go to the high or medium ranges in the air.
 Caused by unstable air.
 Made by upward movement, and powerful
acceleration.
 http://www.free-online-private-pilot-ground-school.com/Aviation-Weather-Principles.html

13. Low Clouds
 Stratus clouds are clouds that look like fog and cover
the sky.
 Stratocumulus clouds are clouds that have a scalloped
bottom that looks like long rods or patches.
 Nimbostratus clouds are rain clouds.
 http://www.free-online-private-pilot-ground-school.com/Aviation-Weather-Principles.html

14. Fog
 A cloud that is very close to the ground.
 Happens when Earth cools rapidly by radiation.
 Cool air goes over warm water, evaporation occurs, air
becomes saturated, and water vapor meets cold air and
it condenses and mixes with the warm air being
warmed.
 http://photoshoptutorials.ws/photoshop-tutorials/photo-effects/fog.html

15. Cold Cloud Precipitation
 Supercooled water is water in the liquid state at 0
degrees Celcius that will freeze when it hits a solid
object.
 When air is saturated with water, it is supersaturated
with ice.
 http://nanopatentsandinnovations.blogspot.com/2010/06/amount-of-dust-pollen-matters-for-cloud.html

16. Warm Cloud Precipitation
 The collision-coalescence process is the process that creates raindrops.
 Particles, such as salt, in the air absorb water so realitive humidity goes below
100% makeing large rain drops.
 The large drops go through the cloud and they join with smaller water droplets.
 https://www.meted.ucar.edu/sign_in.php?go_back_to=http%253A%252F%252Fwww.meted.ucar.edu
%252Ftropical%252Ftextbook_2nd_edition%252Fprint_5.htm

17. Rain and Snow
 Snowflakes usually melt when the temerature at the surface is above 4 degrees Celcius, so
snowflakes usually melt before they hit the ground.
 When there is a low humidity, snow crystals form.
 Snow crystals mix together into clumps when the temerature is above -5 degrees celcius.
 http://kohd.com/page/213587
 http://roymiller.hubpages.com/hub/quotes-about-rain

18. Sleet, Glaze, and Hail
 Sleet is small pieces of ice falling from the clouds.
 Glaze is freezing rain that happens when rain is supercooled.
 Hail is small ice pieces that grow as they fall by collecting supercooled water. Hail can
become very, very large. Some can even be the size of softballs.
 http://en.wikipedia.org/wiki/File:Sleet_on_the_ground.jpg
 http://www.tornadochaser.net/hail.html

19. The End!