This document discusses various topics related to clouds and precipitation, including how adiabatic temperature changes can cause air to cool, how different types of lifting mechanisms like orographic lifting and frontal wedging can cause clouds to form, the different types of clouds like cirrus, cumulus and stratus clouds, and how precipitation occurs through both warm cloud and cold cloud processes. It also describes different forms of precipitation like rain, snow, sleet, glaze and hail.

1. Clouds and Precipitation
 By: Lexi Montgomery
 http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/h
ome.rxml

2. Adiabatic Temperature Changes
and Expansion and Cooling
 Adiabatic temperature changes are temperature
changes that happen even though heat isn’t added or
subtracted.
 Wet adiabatic rate is the rate of adiabatic cooling in
saturated air and it is always slower then the dry
adiabatic rate.
 http://apollo.lsc.vsc.edu/classes/met130/notes/chapte
r6/adiab_cool.html

3. Orographic lifting
 Orographic lifting of air occurs when elevated terrains,
such as mountains, act as barriers to air flow, forcing
the air to go otherwise.
 http://ag.arizona.edu/watershedsteward/resources/m
odule/Climate/az-climate_pg2.htm

4. Frontal wedging
 The boundary between colliding warm and cold air is a
front.
 The process that occurs at a front which cold, dense air
acts as a barrier over warmer, less dense air is frontal
wedging.
 http://www.harding.edu/lmurray/113_files/HTML/d2_
Earth%20Revised/sld046.htm

5. Convergence
 The lifting of air that results from air in the lower
atmosphere flowing together is convergence.
 http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/d
vlp/cnvrg.rxml

6. Localized Convective Lifting
 When unequal heating of Earth’s surface warms a
pocket of air more than the surrounding air, making
the air pockets density lower is called localized
convective lifting.
 http://wps.prenhall.com/esm_lutgens_foundations_4
e/47/12104/3098876.cw/content/index.html

7. Stability (Density Differences &
Stability and Daily Weather)
 When air temperature increases with height is when
the most stable conditions happen. This is called
temperature inversion.
 http://www.meted.ucar.edu/afwa/avalanche/print.ht
m

8. Condensation
 When condensation occurs in the air above the
ground, little pieces of a specific matter , called
condensation nuclei, are for surfaces for water-vapor
condensation.
 http://keep3.sjfc.edu/students/kes00898/e-
port/condensation%20page%20for%20unit.html

9. Types of Clouds
 Cirrus clouds are high in the sky, white and thin. These
types of clouds occur as patches or as delicate sheets or
extended wispy fibers that often have a feathery look.
Cirrus also stands for (a curl of hair)
 Cumulus clouds are the clouds that consist of rounded
individual cloud masses. They usually have a flat base and
appear as rising towers or domes. Cumulus also stands for
(a pile)
 Stratus clouds are the clouds that are described as sheets or
layers that cover a good amount of the sky. Stratus also
stands for (a layer)
 http://eo.ucar.edu/webweather/cloud3.html

10. High Clouds
 3 cloud tpes make up the family of high clouds. Cirrus,
cirrostratus, and cirrocumulus.
 Cirrocumulus clouds are fluffy, they have flat layers
and warn any stormy weather.
 All high clouds are thin, white and are often made of
ice crystals.
 http://www.enchantedlearning.com/subjects/astrono
my/planets/earth/clouds/

11. Middle Clouds
 Clouds that appear in the middle range (2,000-6,000
meters)
 Altocumulus clouds are rounded and differ from
cirrostratus clouds.
 These clouds are white and grayish, you also might get
a light snow or drizzle with these clouds.
 http://scienceprep.org/clouds.htm

12. Low Clouds
 3 types of low clouds; stratus, stratocumulus, &
nimbostratus.
 Stratus clouds have a fog-like layer that covers much of
the sky. Stratocumulus forms when stratus clouds
develop a scalloped bottom or in broken rounded
patches. Nimbostratus get the name from latin
(nimbus) means rainy and cloudy these form during
stable conditions.
 http://anthonyjstewart.wordpress.com/2009/05/28/ch
icago-low-clouds-and-mist/

13. Clouds of Vertical Development
 Some clouds don’t fit into the 3 categories
 When upward movement happens acceleration
happens with clouds with a large vertical range form
 http://www.uwgb.edu/dutchs/EarthSC102Notes/102Cl
ouds.htm

14. Fog (by cooling and by
evaporation)
 Fog can form on warm and cool air.
 As the night progresses, a thin layer of air in contact
with the ground is cooled below its due point, as it
cools it will become more dense.
 http://ocw.usu.edu/Forest__Range__and_Wildlife_Sci
ences/Wildland_Fire_Management_and_Planning/Un
it_4__Temperature-Moisture_Relationship_7.html

15. Cold Cloud Precipitation (Bergeron
process)
 The Bergeron process is a theory that relates the
formation of precipitation to very cold clouds, freezing
nuclei, and the different saturation levels of ice and
liquid water.
 Supercooled is when water in the liquid state is below
0 degrees Celcius.
 http://rst.gsfc.nasa.gov/Sect14/Sect14_1d.html

16. Warm Cloud Precipitation
(collision-coalescence process)
 Supersaturated is when air is saturated (100% realative
humidity) with respect to water. With ice (greater than
100% humidity)
 Collision-coalescence is a theory of raindrop
formation in warm clouds in which large cloud
droplets collide and join together with smaller
droplets to form a raindrop.
 http://www.liveweatherblogs.com/weatherblog/5568/
Clouds-Precipitation-as-earth-s-thermostat

17. Rain and Snow
 Rain means drops of water that fall from a cloud and
have a diameter of at least 0.5 mm.
 At temperatures warmer then -5 degrees Celsius, ice
crystals join together making larger clumps.
 Snowfalls of larger clumps are heavy and make higher
moisture filling.
 http://zahiym5tlc.edublogs.org/

18. Sleet, Glaze and Hail
 Sleet is the fall of small particles of clear to translucent
ice.
 Glaze (freezing rain) is when rain drops become
supercooled, fall to the ground, and turn to ice when
they hit objects.
 Hail is produced in cumulonimous clouds, they start
as small ice pellets that got bigger by connecting really
cold water droplets as they fall through a cloud.
 http://kvgktrailblazers.weebly.com/forms-of-
precipitation.html

19.  THEEEEEEE ENDDDDDD!!!!
 http://www.srh.noaa.gov/jetstream/synoptic/precip.ht
m