Air Masses and Weather Frontshttp://www.inkcinct.com.au/Web/CARTOONS/2006/2006-694-Weather-front-title-fight.jpg

Air MassesAir mass – large body

of air that takes on the characteristics of the area of which it forms (source region)

Over land – drierOver water – more

humidAlso takes on

temperature of source region

http://blogs.redding.com/redding/smobley/archives/3-24-08-today-gfsx_500p_24h.gif

Air Masses - OriginsWhat do you think

Air Mass #1 would be like in April? Cold/Warm? Moist/Dry? Why?

What do you think Air Mass #2 would be like in April? Why?

http://www.kidsgeo.com/images/air-masses.jpg

Air Masses - OriginsMaritime tropical (mT)

warm and humidContinental tropical

(cT)warm and dry

Maritime polar (mP) cold and humid

Continental polar (cP)cold and dry

Arctic (A) even colder!

Air masses don’t just affect the US!!

http://www.geography.learnontheinternet.co.uk/images/weather/air_masses.gif

Worksheet – Transparency 18

Answer questions on the back

Weather FrontsForm where two

air masses with different characteristics collide

Four typesColdWarmOccludedStationary

http://www.bynon.cc/blog/fronts.jpg http://www.windows.ucar.edu/earth/Atmosphere/images/front_superior_epa_lg.jpg

Cold FrontCold air moves in on existing warm air (blue

triangles) Rapidly rising warm air cools, condenses

Thunderstorms common

http://www.physicalgeography.net/fundamentals/7r.html

Cold Front

http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/images/cold-front_lg_gif_image.html&edu=high

Warm FrontWarm air invades area of cool air (red

circles) Warm air rises over cool air cools,

condensesRain common

http://www.physicalgeography.net/fundamentals/7r.html

Warm Front

http://www.windows.ucar.edu/earth/Atmosphere/images/warm-front_lg.gif

Cold Front vs. Warm Front

View Animation

Occluded FrontWarm air gets trapped between two cold fronts (red circles

and blue triangles/purple circles and triangles) Warm air forced up cools, condenses

Complex weather, rain/snow, thunderstorms

http://www.physicalgeography.net/fundamentals/7r.html

Occluded Front

http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/images/occluded_lg_gif_image.html&edu=high

Stationary FrontNo mixing (blue

triangles and red circles)

Air masses push against each other, but neither moves

Parallel windsHard to predict

weather

http://www.windows.ucar.edu/earth/Atmosphere/images/stationary_sm.gif

Weather fronts from Monday

Worksheet – Transparency 19Fill out the questions on the back. Color the front if it helps you.