Extreme Precipitation Projections Using Updated Climate Model Data from LOCA2

Extreme Precipitation Projections Using Updated Climate Model Data from LOCA2

This tool is excerpted from Mid-Atlantic Regional Climate Impacts Summary and Outlook: Spring 2024.

Tool Background

As described in the Winter 2023-2024 Climate Summary, the most recent scientific update to global climate model projections of future climate change – the Coupled Model Intercomparison Project 6 (CMIP6) – are now available for researchers and practitioners as downscaled projections for the United States. This dataset, Localized Constructed Analogues 2 (LOCA2), provides higher spatial resolution (~3.7 square miles) projections of future temperature and precipitation than the global CMIP6 models which have spatial resolutions on the order of tens to hundreds of square miles.1 LOCA and LOCA2 use similar downscaling methods, but LOCA2 was designed with the intention to do a better job of preserving any extremes in daily precipitation from the global climate models.2 A detailed comparison of how LOCA2 is different from LOCA is provided on the LOCA website. For a more complete discussion about and introduction to climate projections and future climate scenarios, see Part 4 of the Winter 2023-2024 Climate Summary.

All of our previous climate summaries have used the previous version of the LOCA downscaled climate models. This is our first summary that incorporates LOCA2 models. In future climate summaries, we will do a more detailed comparison between LOCA and LOCA2, but for now this summary is intended to provide an initial look at these new downscaled climate models.

In this section, we present an analysis of future projected days with extreme precipitation, or days with precipitation totals above 1, 2, or 3 inches.

Key Findings

  • The Mid-Atlantic Region could see more than a 35 percent increase in the average annual number of days with precipitation above 2 inches by the middle of the century and a nearly 60 percent increase by the end of the century under a high future climate scenario (SSP3-7.0).
  • The southeastern portion of the region and locations at higher elevation will generally see greater future instances of days with extreme precipitation, shown in the darker purples and blues in the 1-inch threshold maps. This is consistent with current climatology.

Figure 1. CMIP6 Extreme Precipitation Projections

How to Use the Tool

Selecting Precipitation Thresholds and Time Periods Use the filters to the right of the maps to adjust the precipitation threshold, future time period, and climate scenario.

Technical Notes

Localized Constructed Analogs 2 (LOCA2) is a downscaled climate data product available at 6 km resolution over the continental United States.3 The LOCA2 dataset includes 27 of the climate models available in the Coupled Model Intercomparison Project 6 (CMIP6) archive, for three future climate scenarios: an intermediate-emissions future (Shared Socioeconomic Pathway (SSP) 2-4.5), a high-emissions future (SSP 3-7.0) and a very high-emissions future (SSP 5-8.5).4 For this tool, we used LOCA2 data over the Mid-Atlantic region from 2021-2100 (or 2099 for some models). Access LOCA2 datasets and learn more about the methodology.

Footnotes

  1. Soares, P. M. M., Johannsen, F., Lima, D. C. A., Lemos, G., Bento, V. A., and Bushenkova, A.: High-resolution downscaling of CMIP6 Earth system and global climate models using deep learning for Iberia, Geosci. Model Dev., 17, 229–259, https://doi.org/10.5194/gmd-17-229-2024, 2024. Return to text ⤴

  2. https://loca.ucsd.edu/loca-version-1-vs-loca-version-2/ Return to text ⤴

  3. https://www.midatlanticrisa.org/climate-summaries/2024/03.html#part-4-a-primer-on-climate-pro- Return to text ⤴

  4. https://www.midatlanticrisa.org/climate-summaries/2024/03.html#part-4-a-primer-on-climate-pro- Return to text ⤴