Atlantic Hurricanes Part I
- Due Jan 31 by 11:59pm
- Points 5
- Available until Feb 14 at 11:59pm
HURDAT: Atlantic Hurricane Data 1851-1930
The 2020 hurricane season broke records, including:
- Numbers of tropical depressions and named storms
- Latest-forming Category 5 hurricane on record
- Most storms formed before the usual August-November season
- Most active September on record
- Most landfalls in the United States
Is this a result (and indication) of global climate change? Or is it a statistical outlier? Should we expect a return to “normal”? What would “normal” mean in this context? Or should we – especially those of us who live in low-lying coastal areas – prepare for this to be a “new normal”?
Statistics can help us answer these questions.
Data Sources
HURDAT is the standard reference database for all tropical storms and hurricanes for the Atlantic Ocean, Gulf of Mexico and Caribbean Sea. It has many uses, some of which were not considered when it was first compiled in 1851. It contains some systematic errors, some random errors, and some biases in the historical data base due to a growing understanding of these storms.
An official source is the US National Hurricane center https://www.nhc.noaa.gov/ Links to an external site.. You can also consult https://en.wikipedia.org/wiki/Atlantic_hurricane_season#Operations Links to an external site..
Definitions
The NOAA (National Oceanic and Atmospheric Administration) uses the following definitions:
A Cyclone is an atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
A Tropical Storm is a tropical cyclone Links to an external site. in which the maximum sustained surface wind speed ranges from 39 mph to 73 mph. Storms are generally named when they produce sustained wind speeds of more than 38 mph.
A Hurricane is a tropical cyclone Links to an external site. in which the maximum sustained surface wind is 74 mph or more. The term is used for Northern Hemisphere tropical cyclones east of the International Dateline to the Greenwich Meridian.
A Major Hurricane is one classified as Category 3 or higher.
Named Storms, 1851-1930
The following table records data from an 80-year period from 1851-1930 inclusive.
# of Named Storms |
Frequency (Number of years with the given number of named storms) |
---|---|
0 |
0 |
1 |
1 |
2 |
0 |
3 |
1 |
4 |
7 |
5 |
15 |
6 |
14 |
7 |
10 |
8 |
8 |
9 |
6 |
10 |
5 |
11 |
6 |
12 |
4 |
13 |
1 |
14 |
0 |
15 |
1 |
16 |
0 |
17 |
0 |
18 |
0 |
19 |
1 |
20 |
0 |
Exercises:
- Is this data from a “population” or a “sample”?
- Use technology to find the mean and standard deviation of the data set.
- Construct a histogram for the data set. Use a class width of 2, 3 or 4 (use your best judgment, you will not turn it in)
- Describe the distribution: Is it roughly mound-shaped? Is it symmetric? Is it skewed?
Hurricanes and Major Hurricanes: 1851-1930
The following counts represent the frequency of each type of event from 1851 to 1930:
Numbers of: |
Hurricanes |
Major Hurricanes |
---|---|---|
0 |
2 |
26 |
1 |
2 |
27 |
2 |
5 |
19 |
3 |
18 |
2 |
4 |
17 |
4 |
5 |
11 |
1 |
6 |
14 |
1 |
7 |
5 |
|
8 |
1 |
|
9 |
1 |
|
10 |
4 |
|
11 |
1 |
|
Exercises:
- Use technology to find the mean and standard deviation for each type of event.
- Construct a histogram for each type of event. Use a class width of 2 or 3 for “hurricanes” and 1 or 2 for “major hurricanes” (depending on your teacher’s instructions, if any, or your best judgment).
- Describe each distribution: Is it roughly mound-shaped? Is it symmetric? Is it skewed?
- From 1981 to 2010, the yearly average was 12 named storms, 6.5 hurricanes, and 2 major hurricanes. How did this compare with the 1851-1930 data set?