Storms Like Beryl Are Dangerous Inland, Too: NPR

A home is surrounded by water in Texas. Beryl hit the state as a Category 1 hurricane. The remnants of the storm are expected to move away from the ocean toward the Midwest, where they also pose dangerous flooding risks.

Brandon Bell/Getty Images/Getty Images North America

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Brandon Bell/Getty Images/Getty Images North America

Beryl made landfall as a hurricane in Texas, and as the storm dissipates, it is expected to move deeper into Midwestern states like Missouri, Illinois, Indiana, Michigan — and even Ontario, Canada.

Most people don’t associate flooding far from the coast with hurricanes. But even after these storms lose their hurricane status, break up, and move away from the ocean, they can still cause significant flooding. Climate change is making these storms more dangerous. A warmer atmosphere holds more moisture, which can make rainfall more intense.

Why, exactly, does a warmer Earth mean an increased risk of inland flooding? And what does the future hold? This FAQ is for the millions of people who live in increasingly flood-prone areas of the United States and want to know how to stay safe and prepare for climate change.

How does climate change affect heavy rainfall?

It all starts with the release of greenhouse gases like carbon dioxide and methane. As humans continue to burn fossil fuels, the atmosphere warms. This warm air holds more water vapor, so when it rains, it rains harder.

Climate scientists have predicted for decades that heavy rains will become more frequent as the Earth warms. Now, scientists can measure what’s happening in real time. The amount of rain falling during the strongest storms has increased across the country — in the Northeast, it’s up about 60 percent since the 1950s, according to the National Climate Assessment. The Northeast and Midwest are getting much more rain, which means a much higher risk of flooding in all sorts of places, including areas far from the coast.

Why are inland floods so dangerous?

Because floods can happen very quickly and water can be powerful when it gets moving. When a lot of rain falls in a short period of time, it doesn’t soak into the ground, especially if it’s already saturated or covered with pavers or buildings that aren’t permeable.

All that water has to go somewhere, so it collects on the surface. If there’s a hill, even a very small one, the water starts to move downhill. It builds up energy. That’s how flash floods happen, which can be extremely dangerous. Moving water can rip homes off their foundations, destroy roads, fill underground subway stations, and sweep away cars. It’s one reason why floods are consistently the deadliest natural disaster in the United States.

Is there any warning before a flash flood?

Often a warning is issued. The National Weather Service monitors for signs of heavy rain. If flash flooding is possible, the local weather office will issue a flash flood warning. If flooding is likely, this warning becomes a true flash flood warning.

People with smartphones usually receive an automatic alert when there is a weather warning. It is important to take these alerts seriously and especially avoid areas that have flooded in the past or are low lying. Driving during flash flooding is especially dangerous. Never drive through moving water, even if it appears shallow.

What can be done to protect people from heavy rain?

There are many ways to warn people of impending flooding, slowing the flow of water and allowing it to drain away safely. For example, less roadway helps water soak into the ground. Healthy forests and wetlands also absorb water. Retention ponds are also common, especially near areas with lots of roadways, such as highways and parking lots. Ponds are low-lying, marshy areas where excess water can collect.

In cities, heavy rains cause widespread flooding, in part because underground pipes aren’t large enough to handle the type of rain that falls. Most stormwater management systems in American cities were built decades ago. Installing larger pipes or pipes in new locations is very expensive. But it’s an important piece of the puzzle, especially in dense urban areas where heavy rains are expected to become extremely common in the coming years.

What does the future hold? Will heavy rains intensify?

This will depend on humans being able to stop releasing greenhouse gases. If humans continue to burn huge amounts of oil, gas and coal, the atmosphere will continue to warm and heavy rains will become even more frequent and intense throughout this century.

If humans significantly reduce their greenhouse gas emissions over the next decade, it will help control heavy rainfall, especially later in this century.

This is an updated version of a story originally published in 2022.