Meteorology Seventh Grade Science ~ Mrs. Thomas

A HUGE mass of air can have the

characteristics of the area over which it

occurs.

Warm or HOT Air

Cool or COLD Air

Moist Air

Dry Air

http://disney-clipart.com/mickey-mouse/mickey-mouse/mickey-mouse20.php

earth.usc.edu/.../Catalina/WeatherPatterns.html

OBSERVE + DISCUSS

When two air masses of different temperatures meet,

a BOUNDARY is formed between them, called a

front.

http://disney-clipart.com/Ratatouille/Gusteau.php

http://i-love-disney.com/disney-gallery/displayimage.php?album=147&pos=7

A front is a zone of conflict between opposing armies.

HOT DRY air

COOL MOIST

air

http://i-love-disney.com/disney-gallery/displayimage.php?album=147&pos=9

COOL MOIST

air

HOT DRY air

http://disney-clipart.com/Disney-Character-Clipart.php

http://disney-clipart.com/Disney-Character-Clipart.php

• cold air pushes warmer air • warmer air is forced to rise• as boundaries meet, water condenses + precipitation forms• Thunderstorms CAN result• cumulus + cumulonimbus clouds• the temperature DROPS after the front has passed

http://www.physicalgeography.net/fundamentals/images/coldfront.GIF

REMEMBER: COLD or COOL air is heavier and more dense than warm air.

Cooler air has more force than warmer air.

www.aos.wisc.edu/~aalopez/aos101/wk13.html

www.camelotdesign.com/crazy.htm

COLD fronts bring choppy

gusty winds.

www.bbc.co.uk/.../synoptic_charts_rev2.shtml

OBSERVE + DISCUSS

http://disney-clipart.com/Disney-Character-Clipart.php

• warmer air is moving in a region of cooler air

• warmer less dense air rises + slides up and over the cooler air

• warmer air begins to cool as it rises up

• water vapor in the warmer cool has to condense + precipitation will form over a large area

• high cirrus clouds are seen first

• clouds become lower + lower as the front approaches

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

REMEMBER: HOT or WARM air is lighter and less dense than cool air. Warmer air has less force than cooler air.

www.aos.wisc.edu/~aalopez/aos101/wk13.html

etc.usf.edu/clipart/19400/19477/feather_19477.htm

www.camelotdesign.com/crazy.htm “Light as a feather”

type of breeze.

OBSERVE + DISCUSS

http://library.thinkquest.org/C0125863/weather/image/front_stationary_en.gif

• a warm air mass and a cold air mass meet but NEITHER ONE advances• This front can stay in the same location for several days.• cloudiness + precipitation occur along the front• precipitation can be heavy since the front does not move very much

www.camelotdesign.com/crazy.htm

“Stalled” air masses. Not moving.

http://www.thedeets.com/wp-content/uploads/2007/08/arm-wrestling-shocker.jpg

http://ww

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http://www.kidsgeo.com/images/stationary-front_sm.jpg

OBSERVE + DISCUSS

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

library.thinkquest.org/.../weather/front.html

• FAST moving COLD front overtakes a SSSLLLOOOWWW moving warm front• produces cloudy weather with precipitation

REMEMBER: WARM air is lighter and less dense than cool air. Warmer air gets pushed up and out of the way by the rushing COLDER air. But warm air can hold the moisture for the clouds and precipitation.

http://ww

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aunee.k12.wi.us/C

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http://www.mrsciguy.com/sciimages/cyclone04.gif

http://www.pilotfriend.com/training/flight_training/met/images2/12.gif

http://physics.uwstout.edu/wx/u8/U8_12c.gif

http://www.goldiproductions.com/images/cba/weather/weath_coldocclusion.jpghttp://disney-clipart.com/Disney-Character-Clipart.php

OBSERVE + DISCUSS

http://www.bbc.co.uk/schools/gcsebitesize/geography/images/g_wc_pwc5.gif

OBSERVE + DISCUSS

http://earthscience.files.wordpress.com/2007/05/fronts.jpg

OBSERVE + DISCUSS

earth.usc.edu/.../Catalina/WeatherPatterns.html

Warm Air + Moist

Warm Air + Moist

HOT Air + DRY

COLD Air + DRY

Cool Air + Moist

Cool Air + Moist

http://earth.usc.edu/~stott/Catalina/images/weatherimages.jpg/ninefive.jpghttp://apollo.lsc.vsc.edu/classes/met130/notes/chapter11/graphics/cf_xsect.jpg

http://www.cartoonstock.com/lowres/cza0530l.jpg

http://www.free-online-private-pilot-ground-school.com/images/occluded-front.gif

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On 22 May 2004, a supercell thunderstorm (hereafter referred to as the “Furnas County storm”) developed in extreme northwest KS (southwest of McCook, Nebraska) and moved through Furnas and Harlan Counties, Nebraska, spawning 3 tornadoes during its life cycle (Fig. 1). Tornado T1 was the largest (Fig. 2) but because it was in open country and did no significant damage (light damage to a farm and several trees debarked) was given a rating of F1.

All pictures used in this Power Point Presentation contain web site links to credit intellectual property.

Please follow those links to find more information about AIR MASSES and FRONTS.

This Power Point Presentation was created by Janet Moran, March 2008, for science classes at Copeland Middle School, Rockaway Township, NJ.

Edited by Mrs. Thomas For HBW.