1. Weather Forecasting

2. Fronts
A boundary between 2 air masses of different density, moisture, or temperature
Represented on weather maps by various types of curving lines
Cloudiness, precipitation and storms sometimes occur at frontal boundaries

3. Types of fronts Cold fronts Warm fronts Occluded fronts
Stationary fronts

4. Cold fronts – draw picture
Shown on a map as a blue line with triangles
Occurs when colder air advances toward warm air
Cold air wedges under warm air

5. Warm fronts – draw picture
Shown on a map as a red line with semicircles
Occurs when lighter, warmer air advances over heavier, colder air

6. When cold and warm fronts meet
Warm air is lifted, it cools and water vapor condenses, forming clouds
When the temperature difference between the cold and warm air is large or the cold front moves in quickly:
Thunderstorms and even tornadoes may form

7. warm & cold fronts – draw pictures

8. Occluded fronts Involves 3 air masses of different temperatures:
Colder air
Cool air
Warm air
May form when a cold air mass moves toward cool air with warm air between the two
The colder air forces the warm air upward, closing off the warm air from the surface
Shown on maps as purple lines with triangles and semicircles

9. Occluded fronts- draw picture

10. Stationary fronts
Occurs when a boundary between air masses stops advancing
May remain in the same place for several days
Producing light wind and precipitation
Shown on maps as an alternating red and blue line
Red semicircles point toward the cold air
Blue triangles point toward the warm air

11. Stationary fronts – draw picture

12. Why does weather change?
Air masses
Air pressure
Fronts

13. Severe Weather

14. Thunderstorms
Heavy rain falls, lightning flashes, thunder roars, and hail might fall
Occur in warm, moist air masses and along fronts
Occur when warm air is lifted rapidly as cooler air sinks

15. Tornadoes
A violently rotating column of air in contact with the ground
Occur along fronts when cold fronts rapidly approach warm fronts

16. Hurricanes
Read pages 610 – 611
Answer questions 3a and 3b

17. Extra Information A barometer is used to measure barometric pressure
Maritime refers to water
Continental refers to land
The National Weather Service (NWS) is responsible for tracking hurricanes
Satellite imagery has significantly improved in the last 20 years to help us have a better understanding of hurricanes
The warmest part of a hurricane is the eye of the storm

18. Classwork 2/25 Complete weather forecasting worksheet
Turn in when finished.
If you do not finish in class, it is homework.
If you finish before the bell rings, read a book or work on something from another class.

19. Classwork 2/26
You will work with a partner to complete the Coriolis worksheet.
If you finish before we start to go over it, read a book or Scholastic magazine.