Let's Reminisce: Vapor storms are threatening people, property

By Jerry Lincecum
Special to the Herald Democrat

The summer of 2021 was a glaring example of what disruptive weather will look like in a warming world. In mid-July, storms in western Germany and Belgium brought up to eight inches of rain in two days. Floodwaters ripped buildings apart and propelled them through village streets.

A week later a year’s worth of rain—more than two feet—fell in China’s Henan province in just three days. Hundreds of thousands of people fled rivers that had burst their banks. In the capital city, commuters posted videos showing passengers trapped inside flooding subway cars, pushing their heads toward the ceiling to reach the last pocket of air above the quickly rising water.

In mid-August a sharp kink in the jet stream brought torrential storms to Tennessee that dropped an incredible 17 inches of rain in just 24 hours; catastrophic flooding killed at least 20 people.

None of these storm systems were hurricanes or tropical depressions. Soon enough, though, Hurricane Ida swirled into the Gulf of Mexico, the ninth named tropical storm in the year’s busy North Atlantic season. On August 28 it was a Category 1 storm with sustained winds of 85 miles per hour. Less than 24 hours later Ida exploded to Category 4, at nearly twice the rate that the National Hurricane Center uses to define a rapidly intensifying storm. It hit the Louisiana coast with winds of 150 miles an hour, leaving more than a million people without power and over 600,000 without water for days.

Ida’s wrath continued into the Northeast, where it delivered a record-breaking 3.15 inches of rain in one hour in New York City. The storm killed at least 80 people and devastated a swath of communities in the eastern U.S.

What all these destructive events have in common is water vapor—lots of it. Water vapor—the gaseous form of good old H2O—is now playing an unprecedented role in fueling destructive storms and accelerating climate change. As the oceans and atmosphere warm, additional water evaporates into the air.

Warmer air, in turn, can hold more of that vapor before it condenses into cloud droplets to create flooding rains. The amount of vapor in the atmosphere has increased about 4 percent globally just since the mid-1990s. That may not sound like much, but it is a big deal to the climate system.

A juicier atmosphere provides extra energy and moisture for storms of all kinds, including summertime thunderstorms, nor’easters along the U.S. Eastern Seaboard, hurricanes and even snowstorms. Additional vapor helps tropical storms like Ida intensify faster, too, leaving precious little time for safety officials to warn people of danger.

Scientists have long anticipated that climate change would create more airborne vapor, fueling what might be called “vapor storms” that are unleashing more rain and snow than storms did only a few decades ago. Measurements now confirm that heavy-precipitation events are hitting harder and occurring more often across the U.S. and the globe. Since the late 1980s about one third of U.S. property damage caused by flooding—$73 billion—has been attributed to increases in heavy precipitation.

It’s time we began to expect more vapor storms that damage people and property.

Jerry Lincecum

Jerry Lincecum is a retired Austin College professor who now teaches classes for older adults who want to write their life stories. He welcomes your reminiscences on any subject: jlincecum@me.com.