Go Back
  • For Business
  • |
  • Warnings
  • Data Suite
  • Newsletters
  • Advertising
  • Superior Accuracy™
At least 3 killed amid historic flash flooding in New Mexico town. Click for the latest Chevron right
‘We will not leave’: 173 still missing in Texas flood zone as death toll hits 111. Read more Chevron right

Columbus, OH

70°F
Location Chevron down
Location News Videos
Use Current Location
Recent

Columbus

Ohio

70°
No results found.
Try searching for a city, zip code or point of interest.
settings
Columbus, OH Weather
Today WinterCast Local {stormName} Tracker Hourly Daily Radar MinuteCast Monthly Air Quality Health & Activities

Around the Globe

Hurricane Tracker

Severe Weather

Radar & Maps

News

News & Features

Astronomy

Business

Climate

Health

Recreation

Sports

Travel

For Business

Warnings

Data Suite

Newsletters

Advertising

Superior Accuracy™

Video

Winter Center

AccuWeather Early Hurricane Center Top Stories Trending Today Astronomy Heat Climate Health Recreation In Memoriam Case Studies Blogs & Webinars

News / Weather News

'Upsloping rainfall' with Helene was a major factor in extreme flooding

Several factors created a "perfect storm" that caused flooding the likes of which the Southern Appalachians hadn't seen in over 100 years.

By Jesse Ferrell, AccuWeather meteorologist and senior weather editor

Published Oct 4, 2024 8:45 AM EDT | Updated Oct 4, 2024 1:55 PM EDT

Copied

Drone footage shows the devastation Helene left behind in Swannanoa, North Carolina, on Oct. 2.

The incredible rainfall amounts reported ahead of and during Hurricane Helene in the southern Appalachians during late September were enhanced by a process known as "upsloping" and helped lead to extreme flooding that killed dozens of people.

"There were a number of factors that came together to produce the extreme rainfall that began Wednesday night and Thursday, Sept. 25," AccuWeather Chief On-Air Meteorologist Bernie Rayno explained.

One significant factor was what meteorologists call "upsloping."

A cold front had stalled across the Southeast and produced over 6 inches of rain in the mountains before Helene even arrived—something that may have been a "predecessor event," meteorologists say. Predecessor events bring heavy rain inland before tropical storms and hurricanes and are a new type of phenomenon that meteorologists are just beginning to research.

Next, fueled by rich Gulf of Mexico moisture, Hurricane Helene was already producing heavy rain as it began to move over the same area.

As Helene tracked into Tennessee—not a typical track for a tropical storm—tropical air was forced to move up the mountains. When air is forced upward, it gets increaingly moist and causes rainfall to intensify. This "upsloping" setup made the rain heavier than if Helen had tracked over flat land.

A North Carolina woman recorded the moment a mudslide came crashing through her yard during Helene. ⁣ pic.twitter.com/vg2atOEXW8

— AccuWeather (@accuweather) October 2, 2024

The mountainous terrain in the southern Appalachians is known for causing sudden flash flooding. Walls of water that move downstream quickly and are hard to escape from quickly became deadly. Once roads were washed out over a wide area and took utility and communication infrastructure with them, people were cut off from travel, relief organizations and medical assistance.

More to read:

1 storm, more than 100 dead and a 500-mile path of destruction
Catastrophic loss, destruction after Helene leaves at least 213 dead
Tropical threat to bring a new flash flood risk to Florida
Report a Typo

Weather News

video

House swept away by raging floodwaters in New Mexico

Jul. 8, 2025
Weather News

‘We will not leave’: 173 missing in Texas floods, death toll hits 111

Jul. 9, 2025
Weather News

US Coast Guard rescue swimmer hailed as a hero after saving 165 kids f...

Jul. 8, 2025
Weather News

The faces of the Texas flooding tragedy

Jul. 7, 2025
Severe Weather

Severe weather to rumble in the central US through the holiday weekend

Jul. 6, 2025
Weather News

Record sargassum seaweed piles up on Caribbean islands, Gulf

Jul. 2, 2025
Weather News

Alabama teen in ICU after lightning strike hits boat, causing burns an...

Jul. 2, 2025
Show more Show less Chevron down

Topics

AccuWeather Early

Hurricane Center

Top Stories

Trending Today

Astronomy

Heat

Climate

Health

Recreation

In Memoriam

Case Studies

Blogs & Webinars

Top Stories

Weather News

Deadly flash flooding devastates wildfire-scarred New Mexico town

13 minutes ago

Weather News

Camp Mystic, site of deadly Texas flooding, is in 'Flash Flood Alley'

13 hours ago

Weather News

‘Oh my God, we’re floating’: What people faced in amid Texas floods

1 day ago

Weather Forecasts

Flash flood threat to continue in central Texas into midweek

1 hour ago

Severe Weather

Flooding downpours, severe thunderstorms to mitigate heat in East

15 hours ago

More Stories

Featured Stories

Travel

FAA investigating part of a Delta Air Lines wing fell onto a driveway

5 days ago

Health

Three hospitalized, 21 injured after bee attack in France

1 day ago

Weather News

France leads Europe in saying au revoir to beach and park smoking

5 days ago

Weather News

125,000-year-old ‘fat factory’ run by Neanderthals discovered

1 day ago

Weather News

An ambitious vision of a city built from lava

1 day ago

AccuWeather Weather News 'Upsloping rainfall' with Helene was a major factor in extreme flooding
Company
Proven Superior Accuracy About AccuWeather Digital Advertising Careers Press Contact Us
Products & Services
For Business For Partners For Advertising AccuWeather APIs AccuWeather Connect RealFeel® and RealFeel Shade™ Personal Weather Stations
Apps & Downloads
iPhone App Android App See all Apps & Downloads
Subscription Services
AccuWeather Premium AccuWeather Professional
More
AccuWeather Ready Business Health Hurricane Leisure and Recreation Severe Weather Space and Astronomy Sports Travel Weather News Winter Center
Company
Proven Superior Accuracy About AccuWeather Digital Advertising Careers Press Contact Us
Products & Services
For Business For Partners For Advertising AccuWeather APIs AccuWeather Connect RealFeel® and RealFeel Shade™ Personal Weather Stations
Apps & Downloads
iPhone App Android App See all Apps & Downloads
Subscription Services
AccuWeather Premium AccuWeather Professional
More
AccuWeather Ready Business Health Hurricane Leisure and Recreation Severe Weather Space and Astronomy Sports Travel Weather News Winter Center
© 2025 AccuWeather, Inc. "AccuWeather" and sun design are registered trademarks of AccuWeather, Inc. All Rights Reserved.
Terms of Use | Privacy Policy | Cookie Policy | About Your Privacy Do Not Sell or Share My Personal Information

...

...

...