Unprecedented Rainfall: Hurricane Helene and Catastrophic Flooding…

Over 40 trillion gallons of rainfall inundated the Southeastern United States due to Hurricane Helene and preceding storms, leading to catastrophic flooding and over 100 reported fatalities. Meteorologists emphasize that the extreme precipitation is part of a trend towards wetter storms linked to climate change.

In a remarkable meteorological event, the Southeastern United States experienced an unprecedented deluge of over 40 trillion gallons of rainfall, contributed largely by Hurricane Helene and a preceding rainstorm. This extraordinary accumulation of water is enough to fill the Dallas Cowboys’ stadium 51,000 times or Lake Tahoe just once. Specifically, if concentrated over North Carolina, the rainfall would measure approximately 3.5 feet deep, equating to over 60 million Olympic-sized swimming pools filled with water. Ed Clark, the Director of the National Oceanic and Atmospheric Administration’s National Water Center, noted, “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 rainfall has resulted in catastrophic flooding, with officials reporting more than 100 casualties. Ryan Maue, a private meteorologist and former NOAA chief scientist, utilized precipitation data measured within grids to ascertain that the eastern United States received 40 trillion gallons by the end of the week, with significant portions falling in Georgia, Tennessee, the Carolinas, and Florida as a result of Hurricane Helene. Clark corroborated Maue’s findings, stating that the 40 trillion gallon estimate—equivalent to 151 trillion liters—is reasonable, possibly conservative, suggesting that an additional 1 to 2 trillion gallons may have fallen, particularly in Virginia. Furthermore, Clark highlighted that the amount of rainfall exceeds twice the combined capacity of Lake Powell and Lake Mead in the Colorado River basin. Meteorologists attribute this extreme weather phenomenon to a confluence of two or three storm systems. Prior to Helene’s impact, a low-pressure system had stalled over the Southeast, drawing in warm moisture from the Gulf of Mexico. Additionally, a storm that narrowly missed attaining named status lingered along the North Carolina coast, unloading as much as 20 inches of rain, as reported by North Carolina state climatologist Kathie Dello. Helene, recognized as one of the largest storms in recent years, contributed significantly due to its youthful characteristics and rapid movement before making landfall in the Appalachians. Maue remarked, “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 elevations, talking 3,000 to 6,000 feet. And when you drop trillions of gallons on a mountain, that has to go down.” These interactions between the storm systems and mountainous terrain exacerbated the flooding, as higher elevations contributed to increased moisture extraction from the atmosphere. The highest recorded rainfall within North Carolina reached 31.33 inches in the small town of Busick, while Mount Mitchell registered over 2 feet. Clark shared his previous experiences, 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, the more isolated events in eastern Kentucky, and portions of South Dakota, we’re seeing events year in and year out where we are measuring rainfall in feet.” Meteorologists cited climate change as a substantial factor in progressively wetter storms. According to physicists, for every degree Fahrenheit increase in temperature, the air can hold nearly 4% more moisture. Given that the planet has warmed over 2 degrees Fahrenheit since pre-industrial times, this has significant implications for storm intensity and rainfall amounts. Corbosiero stated that experts are actively discussing the contributions of climate change to Hurricane Helene’s precipitation levels. A preliminary analysis suggested that climate change may have increased rainfall in specific regions by 50% during Helene’s impact. Dello emphasized the observable signs of climate change, noting, “We have seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And 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.”

The article discusses a significant weather event that resulted in an extraordinary volume of rainfall across the Southeastern United States, primarily caused by Hurricane Helene and preceding storm systems. Meteorologists estimate that this rain amounted to over 40 trillion gallons, leading to widespread flooding and numerous fatalities. The article also examines the role of climate change in exacerbating such weather patterns, highlighting the increasing intensity of storms and changes in precipitation levels.

In summary, the recent rainfall experienced across the Southeastern United States, exceeding 40 trillion gallons, represents an extraordinary meteorological event largely attributed to Hurricane Helene and other storm systems. The sheer volume of rain has resulted in devastating impacts, with significant loss of life and extensive damage noted. The phenomenon points to larger trends in extreme weather, potentially driven by climate change, underscoring the need for continued observation and study of these evolving environmental conditions.

Original Source: abcnews.go.com