By MU Meteorology Students:
Philip Bergmaier, Elmer Bauers IV, Katie
Nohe, Sarah Miles, & Travis Toth
Main Components of Weather
The Water Cycle
Clouds
Weather Instruments
Weather Forecasting
Temperature
Wind
Important Components of Weather
Humidity
Air Pressure
Temperature
 Definition: The measure of how much heat is in the air
 Important for “making weather happen”
 Measured using a thermometer
wcau.nbcweatherplus.com
Air Pressure
The measure of how much the air is
pushing down on the Earth
Low pressure usually brings stormy
weather
High pressure usually brings clear weather
Air pressure is measured with a barometer
Wind
Wind is created by air moving from high
pressure to low pressure
The 150+ mph winds high in the
atmosphere is called the jet stream
The jet stream winds make weather move
ww2010.atmos.uiuc.edu
Humidity
• Humidity is how much water or moisture is
in the air
• Humid conditions usually come with rainy
weather or hot, steamy days
• Humidity is measured with a hygrometer
A Picture of a Humid Air Mass
www.cls.yale.edu
The Water Cycle
Definition of
the Water
Cycle: A
continuous
exchange of
moisture
between the
oceans, the
atmosphere,
and the land.
-Evaporation:
Liquid to Gas
-Condensation:
Gas to Liquid
-Precipitation:
Falls as Liquid or
Solid
Evaporation
• The Sun heats the water from oceans, lakes,
and rivers
• Water to Water Vapor (Liquid to Gas)
• Air reaches saturation point when it can hold no
more water vapor
http://www.ssec.wisc.edu/data/g8/latest_g8wv.gif
http://www.rap.ucar.edu/weather/satellite/displaySat.php?region=US&isingle=multiple&itype=wv
Transpiration
• Plants can absorb water from the ground
• Evaporation of water from the leaves and
stems of plants
• Accounts for a small portion of all evaporation
in the atmosphere
Sublimation
• Ice to vapor (solid to gas)
• Acts like evaporation, below freezing
Condensation
• Water Vapor to Water (Gas to Liquid)
• Water droplets group together to form:
– Clouds (Condensation at High Levels)
– Fog (Condensation just above Ground Level)
– Dew (Condensation at Ground Level above
32F)
– Frost (Condensation at Ground Level below
32F or when dew forms before ground
freezes)
Precipitation
• Liquid or solid, depending on temperature
• The condensation that occurs in the upper
atmosphere leads to
– Rain
– Hail
Snow
Sleet (Falls as snow, melts,
and freezes again
before hitting the
ground as pellets)
– Freezing Rain (Snow to Rain to Ice)
(Falls as snow, melts, and freezes
on impact with the ground)
Run Off
• Some rain or snow is
absorbed by plants
• Remaining snow melts to a
liquid and the liquid water
runs down to rivers and
underground
• This water eventually travels
to a larger body of water
• The Cycle starts over again
Condensation
Precipitation
Condensation
Transpiration
Evaporation
Run Off
Clouds
Cirrus Clouds
• 20,000+ feet high
• Made up of ice
crystals
• Sign of approaching
precipitation
• Shows direction of
wind high in the sky
www.alanbauer.com
www.weatherwizkids.com
Stratus Clouds
• Indicates rainy or
dreary weather
• Essentially fog
that does not
reach the ground
• Nimbostratus,
stratocumulus,
cirrostratus
Fog
cache.eb.com
Cirrostratus Clouds
www.leslietryon.com
Cumulus Clouds
• Indicates fair weather
• 1 mile up or lower
• May later develop into
cumulonimbus clouds
• Lifetime of 5-40 minutes
www.carlwozniak.com
www.physorg.com
Cumulonimbus Clouds
• Also known as
• The largest types of
thunderstorms
cumulonimbus clouds are
supercell thunderstorms
• Can reach 60,000 feet tall
images.encarta.msn.com
www.atmosphere.mpg.de
www.yorkville.k12.il.us
earthobservatory.nasa.gov
www.top-wetter.de
Mammatus Clouds