1. Air Masses
Large bodies of air
formed when a body of air hangs over a region and takes the temperature and humidity from that region

2. 5 types 1. continental Polar 2. maritime Tropical warm and moist
cold and dry
effects Michigan the most
2. maritime Tropical
warm and moist
Effects Florida

3. 4. maritime Polar
cold and moist
3. continental Tropic
warm and dry
5. continental Artic
Very cold and dry

4. Diagram

5. Boundary between two air masses
FRONTS
Boundary between two air masses
4 types:
1. cold
2. warm
3. stationary
4. occluded

6. COLD FRONT Cold air mass pushes a warm air mass Cumulonimbus clouds
steep slope
brings thunderstorms or severe weather
Cumulonimbus clouds

7. WARM FRONT Warm air mass pushes a weaker cold air mass
little temperature change
brings steady rain
nimbostratus clouds

8. STATIONARY FRONT When two air masses meet but cannot push each other
steady rain for days

9. OCCLUDED FRONT A cold front overtakes a warm front
warm air forced up rapidly
LOW pressure
and storms L

11. Causes of wind 1. Uneven heating of the Earth creates:
2. Differences in air pressure
High pressure area and low pressure area
All winds blow from a High pressure to
a Low pressure

12. 3. CONVECTION CELLS
Warm air rises; cool air sinks

13. 4. CORIOLIS EFFECT Caused by the rotation of the earth
Earth rotates on the average 750mph
faster at the equator
Causes winds to be deflected to
the right in the
Northern Hemisphere

14. Blows from the west to the east Effects the weather the most in the US
WESTERLIES
Blows from the west to the east
Effects the weather the most in the US
TRADE WINDS OR EASTERLIES
Blow from the east toward the equator

16. Isobars- line that connect areas of equal air pressure

17. Isobars and relative wind speed
Isobars- line that connect areas of equal air pressure
Close isobars=high wind speed
Rules:
Low Pressure System: Increased cloudiness, winds, temperatures, and chance of precipitation.
High Pressure System: Indicates clear, cooler temperatures with reduced chance of precipitation.

18. Which state has higher wind speeds Texas or Michigan?
Which state has clear sky's (probably )Texas or Michigan?
Which state has higher wind speeds Texas or Michigan?

20. THUNDERSTORMS Cumulonimbus clouds
-Contain heavy rain, lightning, hail and wind
-Possible tornadoes
-Associated with a cold front
Two of the most important ingredients for thunderstorm formation are instability (unstable air) and moisture.

23. Lightning formation
During a thunderstorm, the Earth's surface has a positive charge. Because opposites attract, the negative charge at the bottom of the thunder cloud wants to link up with the positive charge of the Earth's surface.

24. Lightning produces thunder
1. The electricity passes through the air and starts it vibrating. The vibrations cause sound.
2. The lightning is also very hot and heats up the air around it. Hot air expands and the air gets bigger very quickly, and pushes apart the air particles.
These vibrations are what you hear and call thunder

25. THUNDERSTORM DOWNBURST

26. TORNADOES Form at the base of a cumulonimbus cloud
The formation of tornadoes is the result of warm, moist air meeting cooler, dry air, and creating instability in the atmosphere.
Season: spring to mid-summer
Strongest wind speeds
Ranked on the (Enhanced) Fujita Scale

31. FUJITA SCALE
EF-0
65-85 mph
EF-1
mph
EF-2
mph

32. EF-3
mph
EF-4
mph

33. EF-5
Over 200 mph

41. HURRICANE Cyclone over warm water Pre-existing storm
Has an eye – low pressure in the center

44. KATRINA-2005

45. Has a storm surge- Most dangerous part of a hurricane
Wall of water near the eye
Causes most destruction and loss of life

48. ANDREW-1992

49. Hurricane season June 1- Nov.30
Tropical Depression Wind speeds between 20 and 34 knots (23-39 mi/hr)
Tropical Storm Wind speeds between 35 and 64 knots (40-73 mi/hr)
Hurricane Wind speed greater than 64 knots (74 mi/hr)

50. Hurricane features Rotation : Clockwise or Counter clockwise ?
The eye is the center of the storm.
The eye wall surrounds the eye. The strongest winds and heaviest rains are found in the eye wall.
Rain bands are long, arching bands of clouds and thunderstorms that spiral out from the eye wall.

51. Hurricane season June 1- Nov.30

52. Dissipation
if it moves over land, thus depriving it of the warm water it needs to power itself, quickly losing strength.

53. Damage ?