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