When air masses meet, fronts are formed. Most severe weather occurs near frontal boundaries. Cold fronts bring stormy weather as cold air pushes warm air aloft, while warm fronts bring steady precipitation as warm air slides over cold air. Stationary fronts occur when neither air mass can overcome the other, bringing long periods of clouds and rain.

2. *When convection and winds cause air
masses to move, they bump into one
another.
*The area where two air masses meet is
called a front.
*Most severe weather occurs near frontal
boundaries.
*

3. *

4. *

5. *Cold, dense air is moving toward warm, less dense air.
*The warm air is pushed up to cool and form clouds as the
cooler air replaces it.
*The air on the front side of the boundary line is warmer
than the air on the back side of the boundary line.
*These fronts are usually fast moving and bring stormy
weather and heavy precipitation followed by clearing
skies and higher pressure.
*

6. *

7. *

8. *Warm air is moving toward cold air.
*The warm, less dense air slides over the cold,
more dense air.
*The air on the front side of the boundary line is
cooler than the air on the back side of the
boundary line.
*These fronts usually move slowly and bring
steady rain or snow over many days.
*

9. *Warm and cool air masses that are not strong
enough to move one another
*Sits still for a long period of time
*

10. *

11. *These fronts occur when neither the
cool nor warm air masses are strong
enough to replace each other.
*They tend to stay in an area for a long
period of time, often bringing long
periods of precipitation and clouds.
*

12. * Two cooler air masses meet and force a warm
air mass aloft.
* Brings cool temperatures and large amounts of
rain or snow.
* Followed by clear skies and drier air.
*

13. *

14. *This is when a warm air mass is caught between
two cold air masses.
*The colder air mass moves under the warm air
mass and pushes it up.
*The colder air mass then moves forward until it
meets a cold air mass that is warmer and less
dense.
*The colder air mass moves under this air mass
and pushes it up.
*Brings clear skies and drier air.
*

15. *

16. *

17. http://www.classzone.com/books/earth_science
/terc/content/visualizations/es1903/es1903pag
e01.cfm?chapter_no=visualization
*

18. *The heating and cooling of water and land
produces land breezes and sea breezes.
*High pressure moves toward low pressure,
pushing the warm air upward.
*As warm air rises, cooler air moves in and
replaces it.
*

19. *The Sun heats the water and land every day.
*Land heats up rapidly, but cools off rapidly.
*Desert
*Water heats up slowly, but cools off slowly.
*Swimming at night
*The heat retained by the oceans is what keeps our
planet insulated.
*

20. *

21. *Weather is the atmospheric condition at a
certain time and place.
*Weather maps are used to show current
weather conditions in an effort to predict
future weather conditions.
*You need to know what each symbol
means and how to interpret them to
forecast the weather.
*

22. *Air pressure is measured with a barometer in
millibars.
*Millibars are represented by connected lines of equal
pressure. This is a lot like the topographic map lines.
*The closer together the lines are, the faster the wind
speed.
*The farther apart the lines are, the slower the wind
speed.
*

23. *

24. *Cooler, dense air close to the surface of
the Earth.
*Surrounded by winds flowing in a
clockwise direction.
*Usually brings dry conditions and fair
skies.
*

25. *

26. *Warmer, less dense air above the Earth’s
surface
*Surrounded by winds moving in a
counterclockwise direction.
*Associated with the formation of storms.
*

27. *

28. *

29. *