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Hurricane Harvey, Irma, and Maria 

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wreaked havoc when they made landfall.

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They were all categorized as major hurricanes, 

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but part of what made them so dangerous was how they rapidly intensified before moving inland.

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When hurricanes intensify a large amount in a short period, 

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scientists call this process rapid intensification. 

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This is the hardest aspect of a storm to forecast and it can be most critical to people’s lives.

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While any hurricane can threaten lives and cause damage 

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with storm surges, floods, and extreme winds, 

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a rapidly intensifying hurricane can greatly increase these risks

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while giving populations limited time to prepare and evacuate.

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Rapid intensification occurs when a hurricane’s maximum sustained winds 

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increase at least 35 miles per hour in 24 hours and often results in major hurricanes. 

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The latest Atlantic storm to rapidly intensify was Hurricane Maria, 

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which developed from a Category 1 to a Category 5 hurricane in less than 18 hours.

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In the past few decades, forecasting errors for tracking hurricanes have decreased.

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While intensity forecast errors have shown recent improvement, 

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significant errors can still occur because of rapidly intensifying storms.

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There are, however, clues to a rapidly intensifying hurricane that can be seen from NASA satellites.

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Scientists say ocean water needs to be warm - 80 Degrees Fahrenheit or higher. 

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There also needs to be low vertical wind shear, 

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meaning winds that don’t change much with altitude,

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so that the central part of the storm doesn’t get tilted over or ripped apart.

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A key indicator of a potentially rapidly intensifying storm 

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storm is a symmetrical, deep ring of precipitation surrounding the eye.

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Rapidly intensifying storms typically occur up to twice in a hurricane season.

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But in 2017, we have seen four storms rapidly intensify 

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and scientists attribute this to warmer ocean waters and favorable winds.

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But these key ingredients don’t always lead to rapid intensification 

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-- proving that it’s a much more complex problem.

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Researchers say there are many small-scale processes, such as those associated with deep thunderstorms,

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that influence how strong a hurricane becomes.

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Satellites such as NASA’s Global Precipitation Measurement Mission 

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can observe precipitation inside evolving storms 

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and help scientists better understand how these processes come together to intensify hurricanes.

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