Unprecedented Rainfall from Hurricane Helene and Its Impact on the Southeast U.S.
In a staggering weather event, Hurricane Helene and prior storms inundated the Southeast U.S. with over 40 trillion gallons of rainfall, leading to severe flooding and over 100 deaths. Experts highlight that this volume of rain is unprecedented, with links to climate change contributing to intensifying storm patterns. Meteorologists are researching the implications of such extreme weather events, emphasizing the need for better preparedness and understanding of climate impacts on future weather systems.
In the past week, the Southeast United States experienced unprecedented rainfall, totaling over 40 trillion gallons, primarily due to Hurricane Helene and accompanying weather systems. This volume of water is astonishingly equivalent to filling the Dallas Cowboys’ stadium 51,000 times or Lake Tahoe once. Across North Carolina, if focused there, the rainfall would reach 3.5 feet deep, surpassing one meter. This amount could fill over 60 million Olympic-size swimming pools. Ed Clark, director of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama, remarked, “That’s an astronomical amount of precipitation. I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.” The rains have led to catastrophic flooding, resulting in more than 100 fatalities. Meteorologist Ryan Maue, a former NOAA chief scientist, used satellite data and ground measurements to compute the rains, concluding that 40 trillion gallons fell across the eastern United States, with 20 trillion gallons affecting mainly Georgia, Tennessee, the Carolinas, and Florida due to Hurricane Helene. Both Clark and Maue affirm the accuracy of this figure, with Maue suggesting that an additional 1 to 2 trillion gallons may have accumulated, primarily in Virginia. Clark compared this rainfall to storage in vital Colorado River basin reservoirs, indicating it is more than double what is held in Lake Powell and Lake Mead. Meteorologists believe that the intense rainfall stems from a combination of several storm systems. Prior to Helene’s arrival, a low-pressure system stalled over the Southeast, causing persistent heavy rain and pulling warm, moist air from the Gulf of Mexico. Furthermore, a nearly named storm lingered off North Carolina’s coast, depositing up to 20 inches of rain, as noted by North Carolina state climatologist Kathie Dello. Helene, categorized as one of the most significant storms in recent decades, rapidly collected moisture before facing the Appalachian Mountains. Maue stated, “It was not just a perfect storm, but it was a combination of multiple storms that led to the enormous amount of rain. That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.” The geographical features exacerbated the flooding; the mountains interacted with storm systems, enhancing moisture extraction from the atmosphere. Reports from North Carolina indicate an extreme rainfall measurement of 31.33 inches in Busick, with Mount Mitchell receiving over 2 feet. Reflecting on past storm events, Clark expressed concern, stating, “Before 2017’s Hurricane Harvey, I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet. And after Harvey, Florence, and more isolated events, we’re seeing year after year where we are measuring rainfall in feet.” Increasingly wet storms have been linked to climate change, with Corbosiero and Dello noting that warmer air can hold approximately 4% more moisture for every degree Fahrenheit of warming. Since pre-industrial times, global temperatures have risen over 2 degrees Fahrenheit. Discussions within the meteorological community are ongoing regarding the contributions of climate change versus natural variability. Initial analyses indicate that climate change may have increased rainfall during Helene by 50% in certain areas of Georgia and the Carolinas, as demonstrated in a study by scientists at the Lawrence Berkeley National Lab. Dello remarked, “We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. There would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction.”
This article discusses the significant rainfall and resultant flooding that impacted the Southeast United States following Hurricane Helene. Meteorologists examine the unprecedented volume of rainfall that challenged previous measurements and forecasts, highlighting the interplay between climate change and storm intensity. The article includes insights from experts evaluating historical data and climate patterns to contextualize the severity and implications of such weather events.
The recent inundation of the Southeast U.S. by over 40 trillion gallons of rain underscores a disturbing trend of increasing storm intensity and rainfall attributed to climate change. The catastrophic flooding has claimed numerous lives and caused extensive damage, prompting a reconsideration of storm preparedness measures and a deeper investigation into the relationship between climate change and extreme weather events. The collaborative efforts of meteorologists and climate scientists will be crucial in enhancing our understanding and response to future storm patterns.
Original Source: www.pbs.org
