By MU Meteorology Students:
Philip Bergmaier, Elmer Bauers IV, Katie Nohe, Sarah Miles, & Travis Toth
Main Components of Weather
The Water CycleThe Water Cycle
Weather InstrumentsWeather Instruments
Weather ForecastingWeather Forecasting
Clouds
Important Components of Weather
TemperatureTemperature
WindWind
HumidityHumidity
Air PressureAir 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 weatherAir 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
www.cls.yale.edu
A Picture of a Humid Air Mass
The Water Cycle
-Evaporation:
Liquid to Gas
-Condensation:
Gas to Liquid
-Precipitation:
Falls as Liquid or Solid
Definition of the Water Cycle: A continuous exchange of moisture between the oceans, the atmosphere, and the land.
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 Snow
– Hail 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
Transpiration
Run Off
Evaporation
CondensationCondensation
Precipitation
http://www.btinternet.com/~n.j.f/Y7science/WATER/DragDropWC.htm
Clouds
Cirrus Clouds
www.alanbauer.com
• 20,000+ feet high• Made up of ice
crystals• Sign of approaching
precipitation• Shows direction of
wind high in the sky
www.weatherwizkids.com
Stratus Clouds
• Indicates rainy or dreary weather
• Essentially fog that does not reach the ground
• Nimbostratus, stratocumulus, cirrostratus
cache.eb.com
Fog
www.leslietryon.com
Cirrostratus Clouds
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 thunderstorms
• Can reach 60,000 feet tall
• The largest types of cumulonimbus clouds are supercell thunderstorms
images.encarta.msn.com
www.atmosphere.mpg.de
www.yorkville.k12.il.us
earthobservatory.nasa.gov
www.top-wetter.de
Mammatus Clouds