This document discusses various weather phenomena including: 1) Adiabatic processes that describe how air cools or heats through expansion or compression without transferring heat. 2) Orographic lifting where air is forced to rise over mountain barriers, cooling and potentially causing precipitation. 3) Frontal wedging where denser cold air overrides warmer air at fronts, lifting the warmer air. 4) Different types of clouds like cirrus, cumulus and stratus that form at high, middle and low altitudes respectively.

1. By: Alan Toppel
http://eo.ucar.edu/webweather/basic5.
html http://www.grancanaria-
spain.com/weather.htm
http://www.clker.com/clipart-
cloudy-weather-symbols.html
http://www.clker.com/clipart-6483.html

2. Adiabatic Temperature
Changes and Expansion and
Cooling
 Heat that changes if there is energy
being added or subtracted
 The rate of cooling an heating is
unsaturated calling it dry adiabatic rate
 The rate of cooling is saturated air
calling it wet adiabatic rate
 Wet adiabatic is always slower to
convert to dry adiabatic rate

3. Orographic Lifting
 Orographic lifting is when air occurs
elevation terrains like mountains as a
barrier to let out the flow of air forcing
the air to ascend out from the barrier of
the mountains
 http://www.clipartpal.com/clipart_pd/wea
ther/weathersymbol_10510.html
 http://www.icon-packs.com/stock-
icons/large-weather-icons.htm

4. Frontal Wedging
 A front is a boundary colliding masses of
warm and cool air
 Frontal wedging is a process that occurs
in the (a) front of which cold
 Denser air acts as a barrier over warmer
less dense air as it rises
 http://www.alltacoma.com/tacweather.htm
l

5. Convergence
 Convergence lifts the air resulting from
the lower air in the atmosphere flowing it
together
 The lower the atmosphere the more the
lower air flows together with the
atmosphere
 Lifting air that results from air in the
lower atmosphere flowing together

6. Localized Convective Lifting
 Localized convective lifting occurs
unequally with the heating of the Earth’s
surface
 Earth’s surface warms a pocket of air
more than the surrounded air in the
surface
 Lowering the air pocket’s density
 http://en.wikipedia.org/wiki/File:Nuvola_
weather_snow.svg

7. Stability (Density Differences &
Stability and Daily Weather)
 The most stable conditions is when air
temperature actually increases
 Making it towards it’s height point calling
it temperature inversion
 When stable conditions make the air
increase to the height it becomes
temperature inversion

8. Condensation
 Condensation occurs from the air above
the ground
 Tiny bits of particulate matter calling it
the condensation nuclei
 Its serves as a surface(s) for water-
vapor condensation

9. Types of clouds
 Three types of clouds make up the
family of high clouds
 Cirrus-clouds are high, white, and thin
 Cumulus-clouds consist of rounded
individual cloud masses
 Stratus-clouds are best described as
sheets or layers that cover much or all of
the sky

10. High Clouds
 High clouds- all high clouds are thin and
white and are often made up of ice
crystals-cirrocumulus
 They may warn of approaching stormy
weather

11. Middle Clouds
 Middle clouds-clouds that appear in the
middle range, from about 2,000 to 6,000
meters, they have the prefix alto-as part
of their name-altocumulus
 Infrequent light snow or drizzle may
accompany these clouds

12. Low Clouds
 There are three members in the family
of low clouds stratus, stratocumulus,
nimbostratus
 Occasionally, these clouds may produce
light precipitation

13. Clouds of Vertical Development
 Some clouds do not fit into any one of
the three height categories mentioned.
 Once upward movement is triggered,
acceleration is powerful
 The end result often is a cumulonimbus
cloud that may produce rain showers or
a thunderstorm

14. Fog (by cooling and by
evaporation)
 Fogs can form on cool, clear, calm nights when
Earth’s surface cools rapidly by radiation
 Cooling-As the air cools, it comes denser and
drains into low areas (ex. river valleys)
 Evaporation-Cool air moves over warm water.
 Enough moisture may evaporate from the water
surface to produce saturation

15. Cold Cloud Precipitation
 Ice crystals grow at the expense of
cloud droplets
 Cloud droplets do not freeze at 0
degrees C
 Water droplets then evaporate to
provide a continual source of water
vapor for the growth of ice crystals that
form through the clouds as they fall

16. Warm Cloud Precipitation
 Much rainfall can be associated with
clouds located well below the freezing
level-in the tropics
 Warm clouds the mechanism that forms
raindrops
 Salt can remove water vapor from it’s
relative humidities less than a 100%

17. Rain and Snow
 Rain means drops of water that fall from
a cloud and have a diameter of at least
0.5 mm.
 Snowflakes usually melt and continue to
their descent as rain
 Snowfalls of these snowflakes are heavy
and have high moisture contents

18. Sleet, Glaze and Hail
 Sleet to form a layer of air with
temperatures above freezing
 Glaze also known as freezing rain,
results when raindrops
 Hail is produced in cumulonimbus
clouds
 Hailstone begin as small ice pellets that
grow by collecting super-cooled droplets

19. Merry Christmas!!
 Merry Christmas Ms. Joseph! Have a
good holiday with your friends and
family!
 Sincerely, Alan! ^_^