1. When air is compressed, its temperature increases due to the faster movement of molecules. When it expands, the temperature decreases. Temperature also decreases with increasing altitude, dropping 10 degrees Celsius every 1,000 meters. 2. Mountains prevent air flow and cause the air on the leeward side to be cooler and drier than the windward side. 3. When warm air and cool air collide at a front, the cool air rises over the warm air, acting as a barrier that can prevent storm systems.

1. By Brendan McFadden

2. Adiabatic Temperature
changes, expansion, and
cooling.
 When air is compressed, the molecules
move faster and the temperature
increases. When it can expand, the
temperature decreases.
 Every 1,000 meters from the surface the
temperature goes down 10 c.

3. Orographic Lifting
 Mountains act as barriers to prevent air
flow. That is why the leeward is cooler
than the windward side.
 The moisture in the air decreases by the
time it gets to the leeward side so it
becomes dryer.

4. Frontal Wedging
 Hot air and cool air collide causing a
Front.
 The cool air rises over the warm
air, acting as a wall, which can prevent
storm systems.

5. Convergence
 When air comes from multiple directions
it must go up.
 This causes cloud formation and
adiabatic temperature changes.

6. Localized Convective Lifting
 Unequal heating sometimes causes
sections of air be more heated than
others.
 Warmer air rises and is called a thermal.
That is the process which causes
convective lifting.

7. Stability(Density
differences, stability, and daily
weather).
 Stable air usually stays in its original
position, but unstable air rises.
 The most stable conditions happen in a
temperature inversion, which is when air
temperature increases with height.
 Clouds in unstable air can usually lead
to tornados and thunderstorms.

8. Condensation
 The air MUST be saturated before it can
condense.
 Condensation nuclei, which contain
salt, smoke and dust particles, act as
surfaces for water vapor.
Water Droplets
Salt, Dust , and smoke

9. Types of clouds
 Clouds are known by their height and
form.
 There are 3 types of clouds. Cirrus(High
white and thin), Cumulus( Flat base and
dome), and Stratus( High sheets that
cover much of the sky).
http://en.wikipedia.org/wiki/Cirrus_cloud
http://en.wikipedia.org/wiki/Cumulus_clo
ud
http://urbanext.illinois.edu/kalani/18.cfm

10. High clouds
 Cirrus, cirrostratus, and cirrocumulus
make up the high clouds. They are
white, thin and usually ice crystals.
 This happens because low quantities of
water and low temperatures.
http://www.enchantedlearning.co
m/subjects/astronomy/planets/ea
rth/clouds/

11. Middle clouds
 These clouds appear in the 2000 to
6000 meter range are middle clouds.
 They are larger and denser than high
clouds. They can contain light snow and
rain.
http://scienceprep.org/clouds.htm

12. Low clouds
 These clouds are a fog-like layer that
sometimes has light precipitation.
 Most of the clouds are gray and are in
the surface to 2000 meter range.
http://photos.igougo.com/pictures-
photos-p369775-Low_Clouds.html

13. Clouds of vertical development
 Some clouds don’t fit in to any of the
categories. They are formed in unstable
air
 The result is often thunderstorms and
rain.
http://www.free-online-private-
pilot-ground-
school.com/Aviation-Weather-
Principles.html

14. Fog(by cooling and
evaporation)
 Some fog is formed when warm moist
air flows over cool currents.
 Some forms when cold air leaves the
water and causes it to evaporate from
the water’s surface.
http://www.renderplus.
com/wk/Volumetric_Fo
g_w.htm

15. Cold cloud
precipitation(Bergeron Process)
 Water suspended in air does not freeze
until -40 c. When the water touches an
ice crystal it will supercool.
 This causes snow and snow crystals

16. Warm cloud Precipitation
 Rain is most of the time from clouds
above the freezing level. The collision-
coalescence process causes larger
drops of water to collide with smaller
drops.
 This will make large amounts of smaller
drops and they will be slower.
https://www.meted.ucar.edu/sign
_in.php?go_back_to=http%253A
%252F%252Fwww.meted.ucar.e
du%252Ftropical%252Ftextbook
_2nd_edition%252Fnavmenu.ph
p%253Ftab%253D6%2526page
%253D3.0.0

17. Rain and snow
 Rain is actually small drops of water that
fall from clouds that of a diameter of at
least .5 mm.
 Snow, which usually melts before it
touches the ground, clumps up with ice
crystals and make a heavy moisture
content.

18. Sleet, Glaze, and Hail
 Sleet is small grains of translucent ice
that fall from clouds. A layer of air near
the ground must be subfreezing.
 Glaze is know as freezing rain and must
be super cooled below 0 c. Hail begins
as small ice pellets but can supercooled
and increase in size.
http://climate.met.psu
.edu/features/Hail/PE
MA_hail.php

19. The End