Devastating Rainfall from Hurricane Helene

Typography

Hurricane Helene intensified as it approached Florida’s Big Bend in fall 2024, ultimately making landfall as a Category 4 storm at 11:10 p.m. Eastern Time on September 27. 

Hurricane Helene intensified as it approached Florida’s Big Bend in fall 2024, ultimately making landfall as a Category 4 storm at 11:10 p.m. Eastern Time on September 27. Even while its center was still over the Gulf of Mexico, the hurricane had begun producing devastating outcomes on land. A predecessor rain event and then the main storm system brought heavy precipitation to southern Appalachia starting on September 25. Deadly and destructive flooding occurred as a result in eastern Tennessee, western Virginia, and North Carolina, among other areas.

This map shows rainfall accumulation over the three-day period ending at 7:59 p.m. Eastern Time (23:59 Universal Time) on September 27, 2024. These data are remotely sensed estimates that come from IMERG (the Integrated Multi-Satellite Retrievals for GPM), a product of the GPM (Global Precipitation Measurement) mission, and may differ from ground-based measurements. For instance, IMERG data are averaged across each pixel, meaning that rain-gauge measurements within a given pixel can be significantly higher or lower than the average.

In Asheville, North Carolina, a total of 13.98 inches (35.52 centimeters) of rain fell from September 25 to 27, according to National Weather Service records. The storm swamped neighborhoods, damaged roads, caused landslides, knocked out electricity and cell service, and forced many residents to evacuate to temporary shelters. Record flood crests were observed on multiple rivers in the state. Flooding was widespread across the southern Appalachians; preliminary rainfall totals neared or exceeded 10 inches (25 centimeters) in parts of Georgia, North Carolina, South Carolina, Tennessee, and Virginia.

Read more at NASA Earth Observatory

Image: NASA Earth Observatory image by Lauren Dauphin, using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC.