How Weather Radar Helps Determine Hurricane Categories


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Technology Allows NASA to Track Warm and Cold Air Patterns. Image Credit: NASA

As hurricanes sweep across the coasts, many are glued to hurricane trackers to determine the path and intensity of the storms.

The use of weather radar is critical to determining the strength of a hurricane, particularly since hurricanes form over warm ocean waters.

Forming over the ocean means that they do not immediately make landfall, and so it is hard to study the developing weather systems from land.

It’s important to know what a hurricane might be like before it hits, so that people can make the necessary preparations, including evacuation if necessary.

Weather Radar: Technology Helps Determine The Strength and Path of a Hurricane

Weather radar and satellite photos are one tool that experts use to determine the path of the incoming hurricane. Weather-tracking tools can also measure wind speeds and the pressure in the hurricane, which tells scientists a lot about how the hurricane is developing.

In the case of the infamous Hurricane Sandy, for example, the presence of hot clouds that towered into the troposphere at the beginning of its development was an indication that the hurricane would likely increase in intensity. Tracking hot and cold air patterns also allowed scientists to see that Sandy would merge with a pool of cold air near the Atlantic coast. Weather radar and satellite technologies have brought a modicum of predictability to an unpredictable weather system.

Hurricane Categories Measured on the Saffir-Simpson Scale

The Saffir-Simpson Scale is a scale of hurricane intensity. It is primarily based on wind speed. Hurricanes begin as tropical depressions, which means that they have wind speeds less than those in a hurricane. A Category One hurricane is the lowest level of hurricane, and it has winds of 74 mph or higher. A Category Five hurricane is the highest level of hurricane, with winds over 157 mph. Hurricane Katrina made landfall with a Category Three  status, for example. These hurricanes cause catastrophic damage.

Why Hurricane Categories Are Only Part of the Story

As Hurricane Sandy has shown, hurricane categories are only one part of the larger picture of hurricane damage. At its peak, Sandy was a Category Two hurricane. It then moved downward to a Category One, and it was in this category when it hit the eastern United States. At the moment, Sandy is a post-tropical storm, which means that it has wind forces lower than those of a hurricane. In spite of all this, Hurricane Sandy caused tremendous damage, flooding, and blackouts.

Why did this occur? Sandy swept over a large area of populated land. It also merged with another storm to create an even wider storm. Finally, Sandy occurred at a time when tides were already very high, so it had the ability to push water far up onto the land through storm surges.

Hurricane Categories Don’t Tell The Whole Story

Lower categories of hurricanes cause significant damage and loss of life when they happen in populated areas that are not well-prepared for hurricanes. Areas with fewer trees and swamps have a higher likelihood of landslides, flooding, and storm surges as well. If these lower-level hurricanes happen to merge or coincide with other weather conditions such as cold fronts or high tides, they can become much more powerful and extensive. The use of weather radar and other storm-tracking technology helps us know what to expect, and to prepare for it in most cases.


National Hurricane Center. Tools and Data. (2012). Accessed October 30, 2012.

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