A ‘nightmare’ for forecasters: Here’s why hurricanes are getting stronger, faster

Subject :Geography

Context:

As Earth’s climate warms, more storms are undergoing rapid intensification, growing quickly from relatively weak tropical storms to Category 3 or higher hurricanes in under 24 hours, sometimes stunning forecasters and giving residents little time to prepare.
For example, Hurricane Ian was a tropical storm with heavy rain and winds of at least 73 mph.
But experts say the storm is gaining power rapidly and it could intensify dangerously as it nears Cuba within 14 hours.

Here are key facts about how climate change can rapidly intensify tropical storms–

a. Warming oceans fuel higher winds-

More than 90% of the excess heat from human-caused global warming over the past 50 years has been absorbed by the oceans.
Since 1901,sea surface temperatures have risen an average of 14 degrees Fahrenheit per decade, according to data from the National Oceanic and Atmospheric Administration.
That’s crucial because storms gather strength over the ocean. And, the warmer the water, the more power they pick up.
Higher surface temperatures allow hurricanes to reach higher levels of maximum sustained wind, a common metric used to describe the intensity of a storm.
A 2020 satellite image analysis showed that the likelihood of a hurricane strengthening into a Category 3 storm or higher, with sustained winds above 110 mph, has increased by about 8% a decade since

b. Those winds intensify more rapidly

Not only do warmer oceans make storms stronger, they make the rate of intensification more rapid.
Rapid intensification technically refers to an increase of at least 30 knots, or 35 mph, in the maximum sustained winds over a 24-hour period.
The likelihood of a hurricane undergoing rapid intensification has increased to 5% from 1% since the 1980s.
Previous data on rapid intensification-
A number of the past decade’s most intense Atlantic storms intensified rapidly.
Harvey in 2017 was a Category 1 hurricane on the evening of Aug. 24; by the next day, when the storm reached Texas, it was a Category 4 hurricane with 130 mph winds.
Later that hurricane season, Maria intensified from a Category 1 to a Category 5 hurricane within just 15 hours.
In 2021,Hurricane Ida strengthened from a Category 1 with 85 mph winds into a near-Category 5 hurricane with 150 mph winds less than 24 hours later.

c. Vertical wind shear-

Another element is vertical wind shear, or a measure of how much the wind changes in speed or direction at increasing heights in the atmosphere.
Strong vertical wind shear can inhibit the development of hurricanes by tilting the structure of a storm and by forcing cool, dry air into its core. (It’s like pouring cold water on a fire.)

Short notice raises the stakes-

The window of time to make a decision gets smaller for the forecasters.
The increase in the number of hurricanes that intensify quickly and unpredictably can affect a community’s preparedness.