Shared Enterprise Geodata and Services (SEGS) provides an EPA-curated collection of recommended geodata assets that are nationally relevant and support the Agency’s mission to protect human health and the environment. By connecting EPA users with curated datasets and promoting service reuse, SEGS aims to enhance information access, reduce data-storage costs, and improve the consistency and quality of data at the US EPA.

This SEGS content item depicts the count of annual heavy precipitation days averaged over 20 years during the heaviest 1% of precipitation events (“heavy precipitation events”) for all Block Groups in the continental United States. These values are summarized for historical (1995-2014) time period and projected time periods (2040-2059, 2080-2099) using SSP2-4.5 and SSP5-8.5, developed by RTI and EPA in 2024. These data were downloaded on 02/28/2024 from LOCA2 GFDL-CM4 and processed by RTI to calculate average annual count of heavy precipitation events. EPA’s LASSO tool was used to look across models, and GFDL-CM3 was selected as the model that projects the highest median end of century (2100) average annual precipitation changes across all EPA Regions. However, LASSO is based on LOCA, not LOCA2. Since LOCA2 is being used to better represent precipitation extremes in this project, the updated version GFDL-CM4 was selected for the indicator calculations.