Increased Rainfall in Gulf Coast Linked to Atlantic Subtropical High

Increased Rainfall in Gulf Coast Linked to Atlantic Subtropical High

1895‐2018 National Oceanic and Atmospheric Administration (NOAA) Climgrid fall precipitation trends (colors).

As coastal and inundation flooding cause billions of dollars in damage in the United States annually, it’s important to understand the patterns associated with flooding to make a more prepared nation. In a new Geophysical Research Letter, authors Daniel Bishop, Park Williams, and MAPP-funded PI Richard Seager, found that from 1895-2018, fall precipitation increased by 40% north of the Gulf of Mexico in the southeastern United States. This is a result of increased circulation from the western North Atlantic Subtropical High, which enhances moisture transport into the southeast region. In addition, it was found that the increases in southeastern US fall precipitation resulted almost entirely from increases in intensity, not frequency. Furthermore, 87% of the fall precipitation increase was mostly driven by frontal systems (not tropical cyclones). 

Future research is needed to evaluate whether the observed precipitation increases are likely to continue, stabilize, or decline.


Read the paper here


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The Modeling, Analysis, Predictions, and Projections (MAPP) Program is a competitive research program in NOAA Research's Climate Program Office. MAPP's mission is to enhance the Nation's and NOAA's capability to understand, predict, and project variability and long-term changes in Earth's system and mitigate human and economic impacts. To achieve its mission, MAPP supports foundational research, transition of research to applications, and engagement across other parts of NOAA, among partner agencies, and with the external research community. MAPP plays a crucial role in enabling national preparedness for extreme events like drought and longer-term climate changes. For more information, please visit





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