1. The Nature of Storms
Chapter 13

2. How many thunderstorms are happening right now around the world?

3. What’s a Severe Thunderstorm
Winds of 50mph or more
Hailstones measuring 0.75 inches
Produce a tornado
10,000 in the US every year

4. Supercell Thunderstorm
2,000-3,000 a year
Single HUGE thunderstorm
Do the most damage
Whole cloud is rotating
Entire center of cloud= updrafts

5. Tornadoes Begin with air moving on the surface.
Storm updrafts pick this air up
Air begins to stretch out
More stretching = Faster air
Mesocyclone

6. Profile of a Tornado Form in front of cold fronts
Form in southwest winds
Travel to the northeast

7. Record Breakers Longest Touch-Down Most Tornadoes
Tri-State Tornado
Deadliest
Longest Path
On the ground for 219 miles (3.5 hours)
Most Tornadoes
Super Outbreak of 1974
148 tornadoes
315 fatalities
5,000 injured

8. Fujita Tornado Intensity Scale
Used after the tornado has occurred
Based upon damage caused
Old version = misleading
Doesn’t differentiate between structures
Enhanced: Differentiates between structures

9. Cartoon

10. Severe Thunderstorm Hazards
1). Lightning
2). Tornadoes
3). Flash Flooding

11. Lightning
When there is lightning it is not safe to be outside; you could be struck.
80% of victims are males between the ages of

12. Lightning Myths 1). It can’t occur without rain
2). Rubber soles of shoes or car tires can protect you
3). People can carry an electrical charge
4). Heat lightning means the thunderstorm is far away so you cannot be struck by lightning.
5). All lightning strikes the ground.

13. How does lightning work?
During a thunderstorm, particles at the bottom of clouds take on a negative charge.
More positive by the Earth.
Electrical current, in the form of lightning, passes down to the ground
Picks up a positive charge (Like a hand)
Returns to cloud.

14. Most Lightning Strikes
When it comes to being a human lightning rod Roy C. Sullivan is the iron clad holder of the title.
Roy C. Sullivan was a U.S. forest ranger in Shenandoah National Park in Virginia and it seemed that having an electric personality prerequisite for his job.
Lightning strike #1 came in 1942 in a fire lookout tower.
Lightning strike #2 came in 1969when he was in his truck.
Lightning strike #3 came in 1970 in his front yard.
Lightning strike #4 came in 1972 in a ranger station.
Lightning strike #5 came on August 7, 1973 while he was in his car.
Lightning strike #6 came on June 5, 1974 in a campground.
Lightning strike #7 came on June 25, 1977 while fishing.

15. Cartoon

16. Flash Flooding Causes the most deaths out of all thunderstorm hazards
3 Ways for Flash-Flooding to Occur
1). Heavy Rains in a small area
2). Great volume of rain in a short time
3). Urban areas receiving lots of rain in a short time

17. Flash Flood Videos http://www.youtube.com/watch?v=vfT5dEKaUdk

18. Hurricanes Require Warm Ocean Water Occur in Late Summer
Coriolis Force Causes Rotation

19. Hurricane Comic Strip
You are going to have a comic square for each of these stages of a hurricane
Each square should have some words or a picture that help you distinguish between stages
Make them Funny…But Appropriate!!
Remember….Comics Should Be Entertaining
We will share 

20. Model For Your Comic Strip
You Comic Strip Should Have Four Boxes

21. Hurricanes Stages 1). Tropical Disturbance 2). Tropical Depression
3). Tropical Storm
4). Hurricane

22. Tropical Disturbance Band of thunderstorms Located in the tropics
Air rises because
It is warm
Waves

23. Next Stages Tropical Depression
When a tropical disturbance reaches warm ocean water
Wind speeds = 37 mph
Tropical Storm
Wind is moving up to 74mph
Hurricane
Wind is traveling faster then 74mph

24. Tropical Storm vs Hurricane

25. Put the four stages of a hurricanes lifecycle in order
Try to do this without any notes!!
Put the four stages of a hurricanes lifecycle in order

26. Cartoon

27. Names/Stages of a Hurricane
“Hurricane" is given to systems that develop over the Atlantic or the eastern Pacific Oceans.
In the western North Pacific and Philippines, these systems are called "typhoons"
In the Indian and South Pacific Ocean, they are called "cyclones".
Tropical Disturbance
Band of thunderstorms
Located in the tropics
Air rises because
It is warm
Waves
Tropical Depression
When a tropical disturbance reaches warm ocean water
Wind speeds = 37 mph
Tropical Storm
Wind is moving up to 74mph
Hurricane
Wind is traveling faster then 74mph

28. Parts of a Hurricane Eye: Center of the rotating storm
Calm
High Pressure: Air is sinking
Eyewall: Location of the fastest winds
Air is rising

29. Hurricane Death How do hurricanes lose energy?
Move over land → lose moisture
Move over colder water → lose heat supply

30. Saffir-Simpson Hurricane Scale
Rates hurricanes based upon current conditions
A hurricane moves through different levels throughout its life.
1-5 scale
Based upon storm surge and pressure
Saffir–Simpson Hurricane Scale
Category
Wind speed
Storm surge
mph (km/h) (kn)
ft (m)
Five
≥ 156 (≥ 250) (≥ 136)
> 18 (> 5.5)
Four
131–155 (210–249) (114–135)
13–18 (4.0–5.5)
Three
111–130 (178–209) (96–113)
9–12 (2.7–3.7)
Two
96–110 (154–177) (83–95)
6–8 (1.8–2.4)
One
74–95 (119–153) (64–82)
4–5 (1.2–1.5)
Additional classifications
Tropical storm
39–73 (63–117) (35–63)
0–3 (0–0.9)
Tropical depression
0–38 (0–62) (0–34)
0 (0)

31. Hurricane Destruction
1). Storm Surge
2). Wind Damage
3). Flash Flooding

32. Storm Surge Rise in sea level Caused by hurricane force winds
Looks like a wall of water rushing in
Causes 90% of all hurricane deaths

33. Instant Flooding Hurricanes produce a lot of rain
Causes Flash Flooding
A lot of rain in a small amount of time
Worse if combined with storm surge

34. Wind Damage
mph winds
These change in intensity depending on your location and the path of the hurricane

35. Watches vs Warnings Watch Warning Specific Area
Possibility of coastal areas being struck
36 hour notice
Warning
More Severe
Hurricane force winds are expected to arrive
Less then 24 hr notice

36. Heat Wave Cartoon

37. Reoccurring Weather Floods: Abundance of water
When storms hang around
Droughts: Lack of rainfall
Extended period with no rain or below average rainfall
Result of high pressure systems

38. Temperature Extremes Heat Waves Cold Waves
Extended Period of Above Normal Temperature
Associated with High Pressure Systems
High Humidity
Cold Waves
Extended Period of Below Normal Temperature
High Pressure System of Polar Origin
Wind Chill: How cold does it feel
Combo of cold air and wind

39. Extra Credit Question
What is the name of the tornado that crossed the three states and caused the most deaths?
What three states did it cross?