Dataset DOI: 10.5061/dryad.jq2bvq8q2

Description of the data and file structure

Lists of locations and times of points exceeding average recurrence interval thresholds (defined by NOAA Atlas 14) for three gridded precipitation datasets and the output of a regional climate simulation (CONUS404). 

Files and variables

The naming convention for the included files is as follows:

<dataset>_<startyear>-<endyear>_<datatype>_<ARI>y<duration>h

dataset is one of:

• stage4 (NOAA Stage IV analysis)
• prism (PRISM analysis)
• mrms (MRMS system)
• conus404 (CONUS404 simulation).

startyear is the first year included in the analysis (either 1981, 2002, or 2018), and endyear is the last year included in the analysis (either 2022 or 2024). 

datatype describes what is included in the file:

• "removed_points" are the exceedance points that were removed by either automated or manual QC methods
• "events" are the points retained and included in the analysis

ARI is the average recurrence interval, either 100 or 1000 years. duration is 24, 48, or 72 hours. 

For durations of 48 and 72 hours, a second set of files is included with the suffix "nooverlaps". This is the dataset with overlapping time periods removed: any grid points in a dataset that had multiple exceedances within 3 days of each other at a given ARI and duration were identified. The date with the highest precipitation amount among these overlaps was retained in the dataset, and the others were removed.

So, for example, the file named "stage4_2002-2024_events_1000y72h_edit_nooverlaps.csv" has the exceedances of the 1000-yr, 72-h ARI in the Stage IV dataset from 2002-2024. Overlapping time periods have been removed in this file. [In the file "stage4_2002-2024_events_1000y72h_edit.csv", points from overlapping time periods have not been removed.]

The structure of each file is otherwise the same, as described below. Each row in a file represents one point on the 4-km grid that exceeded the ARI threshold for that duration. 

Variables

• time: Time in UTC, with the format "YYYY-mm-dd HH:MM:SS"
• lat: Latitude in degrees
• lon: Longitude in degrees
• tp: Total precipitation (mm)
• tp_minus_ari: Total precipitation minus the ARI threshold (mm)
• tp_pct_of_ari: Total precipitation divided by the ARI threshold
• event_num: The event number for this point, obtained from DBSCAN clustering. The event numbers are arbitrary (i.e., that an event was assigned number 1 or 5 has no special meaning.) 

Code/software

Files are in comma-separated value (csv) format, which can be read by standard software packages such as Microsoft Excel, R, and the pandas python package. 

Software used to create these files and perform the QC procedures is in python, available online at https://github.com/russ-schumacher/extremeraindata 

Access information

Other publicly accessible locations of the data:

• Interactive maps showing the data provided here can be found at: https://schumacher.atmos.colostate.edu/precip_monitor/interactive.php

Data was derived from the following sources:

• Stage IV analyses were obtained from Du (2011).
• PRISM analyses were obtained from https://data.prism.oregonstate.edu.
• MRMS data were obtained from a combination of sources, including a local archive maintained at Colorado State University, the Registry of Open Data on Amazon Web Services (AWS) (https://registry.opendata.aws/noaa-mrms-pds), and the archive at the Iowa Environmental Mesonet (https://mesonet.agron.iastate.edu/archive/mrms.php). CONUS404 was accessed via Rasmussen et al. (2023) on the NSF NCAR high-performance computing systems.
• NOAA Atlas 14 was obtained from https://hdsc.nws.noaa.gov/pfds/pfds_gis.html

References

Daly, C., and Coauthors, 2021: Challenges in observation-based mapping of daily precipitation across the conterminous United States. J. Atmos. Oceanic Technol., 38 (11), 1979–1992, https://doi.org/10.1175/JTECH-D-21-0054.1.

Du, J., 2011: NCEP/EMC 4KM Gridded Data (GRIB) Stage IV Data. Version 1.0. NSF NCAR Earth Observing Laboratory, Accessed 25 January 2025, https://doi.org/10.5065/D6PG1QDD.281

Lin, Y., and K. E. Mitchell, 2005: The NCEP Stage II/IV hourly precipitation analyses: Development and applications. Preprints, 19th Conference on Hydrology, Amer. Meteor. Soc., San Diego, CA, [Available online at http://ams.confex.com/ams/pdfpapers/83847.pdf].

Rasmussen, R. M., and Coauthors, 2023: Four-kilometer long-term regional hydroclimate reanalysis over the conterminous United States (CONUS). NSF National Center for Atmospheric Research, Boulder, CO, https://doi.org/10.5065/ZYY0-Y036.888

Zhang, J., and Coauthors, 2016: Multi-Radar Multi-Sensor (MRMS) quantitative precipitation estimation: Initial operating capabilities. Bull. Amer. Meteor. Soc., 97 (4), 621–638, https://doi.org/10.1175/BAMS-D-14-00174.1.

Zhuang, J., and Coauthors, 2023: Pangeo-data/xESMF: V0.8.2. Zenodo, https://doi.org/10.5281/zenodo.8356796.364