Understanding rapid intensification

Courtesy NOAA and Climate Central

Hurricane Ian underwent rapid intensification overnight and now stands with winds of 155 mph. At 10 p.m. yesterday, those winds were at 120 mph and THAT is the classic definition of rapid intensification: when winds increase by 35 mph or more in 24 hours or less! Couldn’t be more on spot.

What does that mean? In terms of total destruction -- winds, storm surge, inland flooding, and tornado damage -- a 120 mph hurricane is 43 times more destructive than a 75 mph hurricane and a 155 mph hurricane is 333 times more destructive than a 75 mph hurricane! Clearly, while a 35 mph wind increase may not seem that much, the exponential power of wind is enormous and the damage factor goes up by seven-fold. Here’s a chart from the National Weather Service showing the differences in total destruction based on wind speed:

courtesy National Weather Service

You can read a full explanation of this chart and wind speed comparison right here.

So what causes Rapid Intensification? Simply put, warm water. More fancy: Tropical Heat Potential (more here). But getting back to simple, the warmer the water and the deeper that warm water is, the more fuel for the hurricane. That warm water means warm air above it and warm air rises. When it rises up into the atmosphere it cools down, releasing its energy. The hurricane becomes stronger.

The water that Hurricane Ian is going over is 86-88 degrees -- I’ve circled its location below:

courtesy Tropicaltidbits.com

What’s concerning is that in the past two decades, the frequency of rapidly intensifying hurricanes continues to go up due to climate change and warming water. Climate Central shows that since 1995 the frequency continues to increase:

This process of RI is seen more frequently since 1995

All of this is due to warmer ocean waters, but the bottom line is the real bottom line: the billions and billions of dollars in damage is a direct result of these stronger hurricanes:

courtesy Climate Central

The die is pretty well cast it seems on a warmer atmosphere and warmer waters, so this threat is likely to continue. The best we can do is build better and stronger at the coast and be prepared for these storms to very often bring in the worst of destruction.

You can read more about Climate Central’s study right here.

Thoughts and positive vibes to Florida today. It’s going to be a long one.


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About the Authors:

KPRC 2's chief meteorologist with four decades of experience forecasting Houston's weather.