How Hurricane Strength Impacts Rainfall Intensity and Coverage

news image
Special Stories
29 Oct 2019 2:37 AM

[Image from NOAA satellite of Hurricanes Katia, Irma and Tropical Storm Jose (from left to right) on September 8, 2017.]

[NOAA]  Heavy and widespread rainfall during landfalling tropical cyclones can cause severe damage, large financial losses, and the loss of life. In 2017 and 2018 alone, U.S. landfalling hurricanes contributed to more than 3,000 deaths and $300 billion in damages. In a new Geophysical Research Letters article, the differences in rainfall intensity and physical extent of rainfall along tracks of tropical cyclones of different intensities were researched. All tracks of tropical cyclones that made landfall in the southern and eastern US during the 20th century were analyzed.

From this research, it was found that major hurricanes that have weakened to tropical storms contributed to heavier rainfall over land during the most recent six decades compared to the first six decades of the 20th century. In addition, after landfall occurs, widespread rainfall was also associated with major hurricanes that have weakened to tropical storms.

[Texas National Guard arrives in Houston, Texas to aid residents in heavily flooded areas from Hurricane Harvey, Aug. 27, 2017. Credit: 1st Lt. Zachary Wes.]

To understand these changes in flooding risk to coastal communities, this research study, in part, draws on NOAA's long-term climate monitoring datasets, including those that have been updated and improved through funding from the Climate Observations and Monitoring Program (e.g. NCEI's Global Historical Climatology Network (GHCN) and the National Hurricane Center's (NHC) HURricane DATabase (HURDAT2).

These results suggest that as major hurricanes make landfall, their weakening intensities could have an increased likelihood of more localized and heavy rainfall intensities, increasing the risk of flash flooding and flood devastation such as witnessed during events like Hurricanes Harvey and Florence.

All Weather News
More
Flood Risk Increasing Across the Ozarks Sunday and Monday

Flood Risk Increasing Across the Ozarks Sunday and Monday

If your Memorial Day weekend plans take you a

25 May 2025 1:20 AM
Severe Weather and Heavy Rain Threat  Across Central and Southern U.S.

Severe Weather and Heavy Rain Threat Across Central and Southern U.S.

A slow-moving system is bringing the threat o

25 May 2025 12:50 AM
Chances of Development Increasing in the Pacific

Chances of Development Increasing in the Pacific

Hurricane Season has begun in the Eastern Pac

25 May 2025 12:40 AM
Strong Storms Possible in Florida & the Southeast This Weekend

Strong Storms Possible in Florida & the Southeast This Weekend

Stormy afternoons have returned to Florida, a

24 May 2025 10:30 PM
NOAA Predicts Above Average 2025 Hurricane Season

NOAA Predicts Above Average 2025 Hurricane Season

COURTESY: NOAAThe mark of 2024’s Atlantic Hur

24 May 2025 3:50 PM
Unseasonably Cool and Wet Weather Gripping the Northeastern U.S.

Unseasonably Cool and Wet Weather Gripping the Northeastern U.S.

A coastal low is moving up the Northeast coas

24 May 2025 2:45 AM
Gulf Coast Heat Continues

Gulf Coast Heat Continues

The stretch of record heat continues in Texas

24 May 2025 2:40 AM