1. Hurricanes vs Tornadoes!

2. Hurricanes and tornadoes are both stormy atmospheric systems that have the potential to cause massive destruction!
They are both caused by instability in atmospheric conditions
However, are they caused by the same types of conditions or different conditions?

3. Both tropical cyclones and tornadoes are atmospheric vortices, but they have little in common
Tornadoes have diameters on the scale of hundreds of meters and are produced from a single convective storm cloud (i.e. a cumulonimbus cloud).
A tropical cyclone, however, has a diameter on the scale of hundreds of kilometers and is made of many convective storm clouds

4. Hurricane - tropical cyclone with sustained winds that exceed 74 mph; accompanied by rain, thunder and lightning
Tornado - rotating column of air that rotates at destructively high speeds, usually accompanied by funnel-shaped downward extension of a cumulonimbus cloud; wind speeds mph!

5. Let’s think of more differences between tornadoes and hurricanes
Think in terms of:
Wind movement – horizontal and vertical component; for example does the wind have to be moving both horizontally and vertically or just one or the other
Is the storm produced when there is a great temperature gradient (think cold and warm front colliding) or in a stable temperature?
Does it occur primarily over land or water?
Lifetime – measured in days or minutes?
Geographic location

6. Similarities between tornadoes and hurricanes
Are there similarities between the two types of storms?
Damages
Preparedness
Are there times when a tropical cyclone can cause a tornado?
Can you give some specific examples?

7. You are going to work with a partner to make a chart comparing and contrasting hurricanes and tornadoes!
When you are done, we will discuss our findings
Also, each pair should find one example where a hurricane caused a tornado. You can write this example on the bottom of your chart

8. Hurricanes
Tornadoes
General description
Rotation
Intensity and scale
Location
Most affected areas
Frequency
Characteristics
Occurrence
Forms of precipitation
Temperature gradient
Size
Shape
Life span
Amount of warning
Effects

9. Hurricanes
Tornadoes
General description
Cyclone that is located in N Atlantic or E Pacific; winds > 74 mph
Rotating column of air w/winds whirling at high speeds usually accompanied by a funnel-shaped downward extension of a cumulonimbus cloud; winds 40 – 300 mph
Rotation
Clockwise in southern hemisphere and counterclockwise in northern
Intensity and scale
Classified into 5 categories according to Saffir-Simpson Wind Scale; wind speed and intensity of damage increases from 1 -5
Fujita or Enhanced Fujita Scale; classified from 0 – 5, according to wind speeds and intensity of damage/effects
Location
N Atlanitc, NE Pacific
All continents except Antarctica

10. Hurricanes
Tornadoes
Most affected areas
Caribbean
Where there is a convergence of warm and cold fronts – midwest US
Frequency
per year
1200 per year in US, Netherlands has highest number of tornadoes per area; most common n spring and even fall
Characteristics
Heavy winds, floods, storm surge, a lot of rain
Strong winds, heavy rain, large hail, strong lightning
Occurrence
Warm areas
Where cold and warm fronts converge, can be anywhere

11. Hurricanes
Tornadoes
Forms of precipitation
Rain
Rain, sleet, hail
Temperature gradient
Small/near zero
large
Size
Diameter of hundreds of kilometer (thousands of times bigger than tornado!)
Diameter of hundreds of meters
Shape
Symmetrical, with often clearly defined center
Varies; ;usually cone shaped
Life span
days
minutes
Amount of warning
Days to weeks; the exact area where the hurricane will hit is known within days, but the storm system will last for longer than that, with changes in its path frequent
Minutes to hours! The conditions for the possibility of a tornado can be predicted hours before an event, but tornadoes rarely leave much more thtn a few minutes warning – sometimes none!

12. Hurricanes
Tornadoes
Effects
Vary

13. Find an example when a hurricane caused a tornado!
1967 – hurricane Beulah- 115 in SE Texas!
1985 – Danny
1994 – Beryl
2004 – Hurricane Ivan caused 117 tornadoes!

14. 2004 – Ivan – most on sept. 17, which developed over a 3 day period in the US, including 37 in VA, 25 in GA 18 in FL, 9 in PA, 8 in AL, 7 in SC, 4 in MD and NC, 3 in WV and 2 in MD
1980 Hurricane Allen spawned the most damaging tornado - $100 million in damage!
1964 – Hurricane Hilda produced the deadliest tornado – killing 22 in Louisiana!