# Hurricane Predictions

Name: _________________________________       Date: _____________

Although it's not possible to predict exactly where and when an individual hurricane will form or strike, scientists are getting better at predicting the number and intensity of storms in a given season. How do they do it? In this activity, you'll explore the data scientists use to make hurricane predictions.

1. Look at this graph relating hurricane frequency to sea surface temperature. The red line shows how mean sea surface temperature (SST) compares to average. Positive numbers are warmer than normal; negative numbers are cooler. The blue line shows total year-by-year activity. Positive numbers show above-average activity; negative numbers show below-average activity.
1. How did hurricane activity correspond to sea surface temperature between 1951 and 1970?
2. What happens to both graphs between 1971 and 1994?
3. What happens to both graphs between 1995 and 1999?
4. Form a hypothesis relating sea surface temperature and hurricane activity.
2. Here's sea surface temperature data from the summer of 2005, when there was a record number of hurricanes in the Atlantic. Read the caption.
1. What does the black box in the center show?
2. Look at the color scale. Is ocean water in the box above or below average temperature?
3. How much (in degrees Fahrenheit) above or below average is the water?
3. Sea level air pressure is another factor. Look at the graphic of pressure in the Atlantic in the summer of 2005. Read the caption.
1. What colors represent lower than normal air pressure?
2. Was sea-level pressure above or below normal in the hurricane development region (black box)?
4. Scientists also look at vertical wind shear, the sudden change in wind speed or direction. When there's a large amount of wind shear, it's tough for hurricanes to form. Look at the graphic and read the text.
1. What does the red color represent?
2. What were vertical wind shear conditions in the hurricane region in the summer of 2005?
3. Hypothesize its impact on hurricane activity.
5. Prevailing winds also play a big part in hurricane formation. Study the graphic.
1. Where do upper-level Easterlies (green arrow) originate?
2. From August to October 2005, what effect were these winds (light blue arrows) expected to have on hurricane formation?