1. Bellringer How might large bodies of water influence climate?
What is transpiration?
What are 2 of the 3 primary greenhouse gases?

2. Severe Weather Thunderstorms, Tornadoes, Hurricanes, etc…

3. Thunderstorms Most often associated with a Cumulonimbus Cloud
Cold fronts often create this condition
Produces UNSTABLE environment

4. Thunderstorm Formation
Thunderstorms have three stages…
The Cumulous Stage: Warm air rising and condensing to form clouds
The Mature Stage: Strong updraft of warm, moist air, AND a strong downdraft of wind and precipitation (hail and lightning can occur in this stage too)
The Dissipation Stage: Surface has cooled, cutting off the warm, moist air that “fuels” the storm

5. Lightning
Created by friction between the rising updraft and the falling downdraft in a cumulonimbus cloud
Creates a separation of charges
Eventually discharge “spark”
“spark” is a bolt of lightning

7. Thunder Lightning strikes, the “bolt” can be as hot as 30,000 degrees
Air surrounding that bolt expands rapidly and then contracts quickly as it cools.
air expands and contracts rapidly enough to break the sound barrier (767 mph)
thunder is a “sonic boom”

8. Thought to be the 1st photograph of a tornado (1884)
Tornadoes
Thought to be the 1st photograph of a tornado (1884)

9. Tornadoes
Violent windstorms that take the form of a rotating column of air
Extends downward from a cumulonimbus cloud
Lower pressure in the center vortex near the ground causes air to rush in from all directions.
Air spiraled upward around the core until it merges with parent thunderstorm deep in a cumulonimbus tower.

10. Tornado Development Less than 1% of thunderstorms produce tornadoes
Most intense tornadoes are associated with supercells (big, cumulonimbus cloud structures).

11. Tornado Classification
Fujita Intensity Scale-
Assesses the damage produced by a storm as it relates to wind speed.
F0- Moderate; mph
F5- Severe; mph
Path of Destruction
Duration

12. Tornado Frequency in the US

13. Tornado Frequency Around the World

14. Cool Tornado Pictures

22. Hurricanes

23. Hurricane Formation
Strike the Caribbean, Gulf of Mexico and the US originate in Africa
Begin as low pressure storm systems over land
Trade Winds blow them out over the warm water of the Atlantic Ocean

24. Continued Growth
Water over the Atlantic Ocean near Africa is warm (80°F) and has lots of moisture in it
Precipitation begins, the rain and cool downdrafts of the Cumulonimbus system are not enough to cut off the updraft (it’s too warm)
Warm, moist air continues to fuel the system of Cumulonimbus clouds, making them bigger, and bigger, and bigger

25. Hurricane Dangers
Most dangerous component of a hurricane is “Storm Surge”
As the storm makes landfall, a mound of ocean water (driven by strong winds AND the “sucking” power of the strong low pressure system) is pushed on shore

26. Hurricane Classification The Safir-Simpson Scale
Type
KNOTS
MPH
millibars
inches of mercury
Feet
Meters
 Damage
Depression
less than 34
less than 39
------
Tropical Storm
Category 1
greater than 980
greater than 28.94
3 - 5
minimal
Category 2
6 - 8
moderate
Category 3
9 - 12
extensive
Category 4
extreme
Category 5
136+
156+
less than 920
less than 27.17
19+
5.7+
catastrophic