Nicole, a resident of Kerrville, is seen standing by the Guadalupe River in Center Point, Texas on July 6. The recent surge of flash flooding across various states like Texas, North Carolina, Illinois, and New Mexico has brought attention to the devastating impact of back-to-back record-breaking flood events.
In Texas, slow-moving thunderstorms unleashed an entire summer’s worth of rainfall on July 4, leading to overflowing rivers and tragically claiming the lives of at least 120 individuals. Similarly, Tropical Storm Chantal brought heavy rainfall to central North Carolina over the weekend, causing severe flooding that resulted in the deaths of six people.
On Tuesday, Chicago experienced a 1-in-1,000-year rainfall event, while Ruidoso, New Mexico faced unprecedented flooding that destroyed homes and claimed three lives. These extreme events occurred in rapid succession, prompting questions about why such intense floods are occurring more frequently.
The summer season is known for flash floods, as the combination of intense heat and moisture-laden air creates favorable conditions for thunderstorms. Warmer temperatures allow storms to produce higher rainfall rates, while slower storm movement can lead to prolonged, heavy downpours that overwhelm drainage systems and cause flash floods.
Areas affected by wildfires, such as Ruidoso, are at heightened risk of flash flooding due to the loss of vegetation that typically helps absorb rainwater. Burn scars create water-repellent surfaces that promote rapid runoff, particularly in steep terrain. The ongoing effects of severe drought can also exacerbate flooding by reducing soil absorption capacity.
Understanding the factors contributing to these devastating floods is crucial in preparing for and mitigating the impacts of future extreme weather events.
In the past week, the impact of climate change has been evident in worsening weather conditions. Fossil fuel pollution is contributing to the intensification of flash floods, making them more frequent and severe. As the Earth’s temperature rises, the atmosphere can hold about 7% more water vapor for every degree Celsius of warming, providing storms with additional fuel for heavy rainfall. This global warming phenomenon is causing moisture-rich air to extend beyond its typical tropical boundaries, resulting in intense rainfall in various regions worldwide.
Simultaneously, the escalation of wildfires and droughts due to rising temperatures is leading to increased burn scars and heightened flood susceptibility in fire-prone areas. The occurrence of heavy rainfall events has surged by up to 71% in certain parts of the United States as a result of global warming. According to a recent study by Climate Central, nearly 90% of major US cities have experienced an increase in hourly rainfall rates since 1970.
Cities like Chicago have witnessed an 8% rise in average rainfall intensity, with recent rainfall surpassing records set in the 1970s for the city’s most extreme short-duration downpour. Many of the nation’s infrastructure systems, including roads, sewers, and drainage networks, were not designed to handle the growing frequency of intense rainfall events that are becoming more prevalent.
While flash flooding has historically posed a threat during the summer months, the evolving climate patterns indicate a shifting landscape of risks. With the atmosphere continuing to warm and rainfall patterns changing, more communities may encounter extreme rainfall events in the future. Stay updated on the latest weather news by signing up for CNN news and newsletters on CNN.com.
