Alliance for Affordable Energy
  • Home
  • Who
  • What
    • Consumer Protection and Education >
      • Regulate Our Pipelines
      • Health Impact Assessment
    • Clean Energy >
      • Renewable & Clean Portfolio Standard
      • Transmission
    • Energy Efficiency >
      • EEFA
    • GS4GND
    • Past Work
  • How
    • New Orleans City Council >
      • Council Actions
    • New Orleans Dockets >
      • UD-22-05 Hurricane Ida Costs
      • UD-22-04 Demand Solutions
      • UD-22-03 Battery Storage
      • UD-22-02 100% Renewable
      • UD-22-01 Storm Reserve
      • UD-21-03 Resilience
      • UD-21-02 Zeta Cost Recovery
      • UD-21-01 Winter Storm Uri
      • UD-20-02 IRP (2021)
      • UD-19-01 RPS
      • UD-18-07 ENO Rate Case
      • UD-18-02 EV Charging
      • UD-18-01 Smart Cities
      • UD-17-04 Reliability
      • UD-17-03 IRP (2018)
    • LA Public Service Commission >
      • LPSC 2022 Election
      • Engage with the LPSC
    • Lawsuits & Appeals
    • Climate Initiative Task Force
  • News
    • The Watchdog
    • People's Power Hour
    • MISO Soup
    • Hurricane Ida
    • Events Calendar >
      • AAE House Party
  • Learn
    • Glossary
    • Timeline
    • Reports
  • Get Involved
    • Support
    • Newsletter
    • Intern and Volunteer >
      • Wimpelberg Intern Fellowship
    • Contact Us

The Watchdog

A blog on energy matters in Louisiana!

Does it seem like it's raining harder? Here's what these LSU researchers found.

8/2/2021

0 Comments

 
Article By David J. Mitchell
Originally published on The Advocate
August 2, 2021
The short answer...yes. Researchers found that storms, on average, became shorter but more intense between 1960 and 2017.
In most places the researchers studied, the number of extreme rain events didn't increase — but it did across much of Louisiana.  And those most extreme storms also dropped more rain than in the past. However, the overall amount of rain that fell each year didn't significantly increase. What changed is how fast it fell, which means individual locations got more water, more quickly.

Louisiana's drainage systems weren't built for this kind of weather. So what do these changing rainfall patterns mean for Louisiana residents? Find out in this Advocate article. 
​​
Picture
In May, a storm dumped 13 inches of rain in six to eight hours on parts of East Baton Rouge, Ascension and Iberville Parishes. It overwhelmed drainage systems and flooded neighborhoods — some of which had avoided inundation in the historic 2016 storm.
​
Two years ago, five inches of rain fell in seven hours in New Orleans, outpacing pumps, swamping streets, stranding cars, and flooding some homes.

These storms struck with little warning and gave residents no time to prepare. They weren't named hurricanes or tropical storms, just random thunderstorms that dropped a huge amount of water over a short time.

New research suggests that kind of weather is becoming more common.


Two LSU researchers, and a third from Southern Illinois University at Edwardsville, have combed through rainfall data from across the Southeast United States, including Louisiana. They found that storms, on average, became shorter but more intense between 1960 and 2017.

In most places the researchers studied, the number of extreme rain events didn't increase — but it did across much of Louisiana.  And those most extreme storms also dropped more rain than in the past. 

However, the overall amount of rain that fell each year didn't significantly increase. What changed is how fast it fell, which means individual locations got more water, more quickly.

Louisiana State Climatologist Barry Keim, one of the authors, said the research presents "huge" implications for local cities and towns.

Keim noted that urban drainage systems, like New Orleans' pump stations, are often built around a 24-hour estimate of rainfall. In the Baton Rouge region, ditches, culverts, detention ponds and pumps have been built to standards tied to certain daily rainfall assumptions.

"So, while the rain (total) is not changing, the characteristics of the rain is changing such that it's making it more difficult to pump the water out of these places because it's coming in shorter bursts," he said.

In New Orleans, storms like those have prompted questions about the adequacy of the Crescent City's century-old pumps, which have also suffered major breakdowns in some rain events, though not the May 2019 storm.

​In the Baton Rouge area, these storms have spurred residents to urge elected officials to limit or even halt new development. Some parishes have put building moratoriums in place while they tighten their rules on new construction.

Some local governments are also planning to buy land to create drainage and retention areas, in hopes of limiting flash flooding.

Keim, fellow LSU researcher Vincent "Vinny" Brown and others recently received a National Oceanic and Atmospheric Administration grant to help the New Orleans Sewerage and Water Board better understand how changing rainfall patterns are affecting that city's drainage system and vulnerable populations.
​
For a local sense of changing rainfall intensity, Brown crunched some additional numbers and found the Baton Rouge Metropolitan Airport has seen average hourly rainfall intensity increase by 11.4% between the years 1960 and 2020.

​The average hourly rainfall in Baton Rouge has risen from an estimated 0.1255 inches per hour in 1960 to 0.1398 inches per hour in 2020. It's a small increase, but a statistically significant one based on the research, Brown said.

Further supporting the idea that rain has become more intense, the annual number of hours that any rain was measured at the Baton Rouge airport has not changed in a statistically significant way since 1960.

To reach the conclusions laid out in three papers published between 2018 and 2020, Brown performed statistical analyses on hourly rainfall totals from the Baton Rouge airport weather station and 49 others across 11 southeastern states between 1960 to 2017.

​Researchers usually look at daily rainfall totals because hourly totals require more intense data work. So this study provided a deeper-than-usual analysis of how rain falls over time.

There were variations across the studied area in the Southeast. But, in all, the rainfall analyses found 44% of the 50 rainfall collection stations across the Southeast saw an increase in average hourly rainfall intensity between 1960 and 2017 while 82% saw the average rainfall duration drop over the same period.

The Louisiana rainfall stations in Baton Rouge, New Orleans and Shreveport all saw statistically significant hourly rainfall intensity increases and rainfall duration decreases during the 58-year-period examined.

The fourth Louisiana station examined, in Lake Charles, did also see a drop in rainfall duration, but its increase in rainfall intensity wasn't big enough to be statistically significant.

Climate science has long predicted that global warming would lead to more intense weather events. A world with warmer oceans and skies laden with more moisture better fuels more extreme storms.

Brown and Keim said the study's design doesn't allow them to pin the changes in Louisiana conclusively on man-made climate change.

"So, it's very, very difficult to attribute something like one rainfall gauge down the street to global changes in the climate, very difficult to do that," Brown said.

But they said the findings do align well with what other climate science has predicted.

Kevin Trenberth, a leading climate researcher and a distinguished scholar at the National Center of Atmospheric Research in Boulder, Colorado, believes there is likely a climate change connection in the studies' findings.

​In an email, Trenberth, who wasn't involved in Brown and Keim's work, also noted the impact rising global temperatures have had on how much moisture the atmosphere holds — 4% more for each degree increase in Fahrenheit, or roughly 5% to 10% more moisture since 1970.

But he added that the time period in the studies, since 1960, "is relatively short for trend analysis given all the weather noise that occurs."

He particularly noted the effect of the El Niño pattern, a warming of Pacific Ocean waters that leads to wetter weather in the Southeast. He suggested analyzing that effect would "better sort out the climate change component."

Keim, one of the LSU researchers, said he's not convinced filtering out the effects of El Niño would change the findings much because El Niño is "generally considered to be pretty random in occurrence."
​
Keim and Brown said they do plan more research that will cull additional rain data. They expect it will better fill in the gaps between the 50 rainfall collection stations they have examined so far.


About the Author

Picture
David Mitchell is a staff writer for The Advocate. He has written articles for dozens of other newspapers including BBC, The Independent, The Telegraph, U.S. News & World Report, Washington Times, Kansas City Star, The Sacramento Bee, and The Times-Picayune | The New Orleans Advocate. 

Email David J. Mitchell at dmitchell@theadvocate.com
Follow David J. Mitchell on Twitter, @Newsiedave

0 Comments




Leave a Reply.

    RSS Feed

    Archives

    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    October 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    August 2019
    July 2019
    June 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    October 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    May 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    December 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    January 2014
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    February 2012
    January 2012

    Categories

    All
    Alexandria Lia
    ALI
    ALI Meiner
    Andrew Wiseman
    Anniversary
    Bia Assevero
    CalGreen
    CCS
    Charles Rice
    Clean Energy
    CLECO
    CLECO FAQ
    CLECO Sale
    CLECO Sale Denied
    CLECO Stock
    CLECO Stock Prices
    CLECO Takeover
    Climate Change
    Clyde Holloway
    CO2
    Coastal Restoration
    Corruption
    Cost
    David Roberts
    Decoupling
    Dirty Energy
    Education
    Elections
    Energy
    Energy Efficiency
    Energy Policy
    Energy Smart
    Entergy
    Entergy New Orleans
    Environmental Risks
    EPA
    FERC
    Gas Plant
    Georgetown
    Government
    Grand Gulf
    Green Building
    Grid Failure
    GSREIA
    Gulf Of Mexico
    Health Risks
    Hurricane
    Hurricane Sandy
    Industrials
    Infrastructure
    IRP
    Land Loss
    Land-Use
    LA Public Service Commission
    LEED
    Liquid Air
    Louisiana
    Louisiana Public Service Commission
    LPSC
    MACQUAIRE
    Mayor's Office
    MISO
    Natural Gas
    New Iberia
    New Orleans City Council
    News
    NRDC
    Nuclear
    Oil & Gas Leases
    People Power
    Pipelines
    Power Grid
    Power Outages
    Power Plant
    Public Interest
    Regulation
    Reliability
    Renewable Energy
    RENEWABLE ENERGY POLICY NETWORK FOR THE 21ST CENTURY
    Resiliency
    Resolutions
    RTO
    Rulemaking
    Sacrifice Zones
    Sea Level Rise
    Solar
    Storage Solutions
    Subsidies
    SWEPCO
    TED Talks
    The Town Walk
    Town Hall Meetings
    Transmission
    Utilities
    Vicki Arroyo
    Watchdog
    Water Conservation
    Water Use
    WDSU
    Wetlands
    WWL Radio

    RSS Feed

Intern & Volunteer
If you want to be a frontline soldier on environmental protection, social justice, or environmental racism, come to Louisiana” –Gary Groesch, Founder of AAE
Calendar
View our events calendar ​for important upcoming community events and public meetings!
Support our work- ensure fair, affordable, and environmentally responsible energy for all.
501(c)3 IRS Notice

Alliance for Affordable Energy
Phone: (504) 208-9761
4505 S Claiborne Ave
New Orleans, LA 70175

Copyright © 2022 · Alliance for Affordable Energy
  • Home
  • Who
  • What
    • Consumer Protection and Education >
      • Regulate Our Pipelines
      • Health Impact Assessment
    • Clean Energy >
      • Renewable & Clean Portfolio Standard
      • Transmission
    • Energy Efficiency >
      • EEFA
    • GS4GND
    • Past Work
  • How
    • New Orleans City Council >
      • Council Actions
    • New Orleans Dockets >
      • UD-22-05 Hurricane Ida Costs
      • UD-22-04 Demand Solutions
      • UD-22-03 Battery Storage
      • UD-22-02 100% Renewable
      • UD-22-01 Storm Reserve
      • UD-21-03 Resilience
      • UD-21-02 Zeta Cost Recovery
      • UD-21-01 Winter Storm Uri
      • UD-20-02 IRP (2021)
      • UD-19-01 RPS
      • UD-18-07 ENO Rate Case
      • UD-18-02 EV Charging
      • UD-18-01 Smart Cities
      • UD-17-04 Reliability
      • UD-17-03 IRP (2018)
    • LA Public Service Commission >
      • LPSC 2022 Election
      • Engage with the LPSC
    • Lawsuits & Appeals
    • Climate Initiative Task Force
  • News
    • The Watchdog
    • People's Power Hour
    • MISO Soup
    • Hurricane Ida
    • Events Calendar >
      • AAE House Party
  • Learn
    • Glossary
    • Timeline
    • Reports
  • Get Involved
    • Support
    • Newsletter
    • Intern and Volunteer >
      • Wimpelberg Intern Fellowship
    • Contact Us