Kristin L. Jaeger Alexander O. Headman Patrick Wurster Malia H. Scott Audrey M. Martinez 20250220 tabular digital data https://doi.org/10.5066/P1HCW9MI This child item contains estimated Self-Calibrated Palmer Drought Severity Index (scPDSI) values and ancillary information for the flowlines in the National Hydrography Dataset High Resolution (NHDPlus_HR, 1946-1999). Files include flowlines within the 12 HUC4 boundaries for the study area (1701-1712). This data release includes new information on drought climate conditions for the Pacific Northwest Region for time periods that correspond to streamflow permanence data and model products that include the National Hydrography Dataset Plus High Resolution flowlines, the Probability of Streamflow Permanence (PROSPER) model, and flow/no flow data from the FLOw PERmanence (FLOwPER) application. The three datasets each include distinctly different information about streamflow permanence for the Pacific Northwest Region and have been assembled together in this Data Release for easier comparison and evaluation. 1946 2023 ground condition Complete None planned -129.8145 -106.8750 50.0642 39.7072 ISO 19115 Topic Category inlandWaters USGS Thesaurus streamflow Producer Defined drought severity USGS Metadata Identifier USGS:65b2d913d34e36a390453499 Common geographic areas Washington Oregon Idaho Montana Wyoming Pacific Northwest No data access constraints. These data are in the public domain in accordance with Creative Commons Zero v1.0 Universal Public Domain Dedication (CC0-1.0) and have no use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Kristin L Jaeger USGS - NW-PACIFIC ISLAND REG Research Hydrologist mailing and physical

WA WSC,Kress/PAyless Building

Tacoma WA 98402 253-552-1617 kjaeger@usgs.gov Funding from USGS Water Availability and Use Program. The authors would like to acknowledge the Bureau of Land Management, the U.S. Forest Service Region 6, and the Oregon Department of Fish and Wildlife. Conversations with personnel from those agencies informed the development of this data release. The high intensity data processing for this study was done using the Denali Supercomputer maintained by Advanced Research Computing group within the U.S. Geological Survey. Susan Wherry Roy Sando Kristin L. Jaeger 2025 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/P13AB8NW Thomas R. Sando David P. Hockman-Wert 2019 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/f77m0754 No formal attribute accuracy tests were conducted. An assumption was made that the accuracy of the estimated values is as good as the accuracy and resolution of the original source data. Checks were conducted to verify values fall within expected ranges and that there is no missing data. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal horizontal positional accuracy tests were conducted. No formal vertical positional accuracy tests were conducted. Western Regional Climate Center 2023 tabular digital data Digital and/or Hardcopy 1946 2023 ground condition WRCC Provided monthly self-calibrated Palmer Drought Severity Index (scPDSI) values for HUC 17. Gregory J. Allord Jennifer L. Walter Kristin A. Fishburn Gale A. Shea 2014 publication n/a US Geological Survey https://doi.org/10.3133/tm11B6 Digital and/or Hardcopy 2020 ground condition PNW_quad_extent Provided “year_of_map” for each quad extent within HUC17 that was used as representative year to which scPDSI was attributed. Konrad C. Hafen Kyle W. Blasch Alan Rea Roy Sando Paul E. Gessler 20200819 publication JAWRA Journal of the American Water Resources Association vol. 56, issue 5 n/a Wiley ppg. 903-916 https://doi.org/10.1111/1752-1688.12871 Digital and/or Hardcopy 20200819 ground condition Hafen_et_al_2020 Provided methods to attribute scPDSI values to the flowlines from the National Hydrography Dataset Plus High Resolution (NHDPlus_HR), based on the map year. Theodore B Barnhart Roy R Sando Seth A Siefken Peter M McCarthy Alan H Rea 2020 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/p9w8uz47 Digital and/or Hardcopy 2020 publication date Barnhart_et_al_2020 Provided methods to pre-process average water year scPDSI values as flow conditioned parameter grids. David G. Tarboton 199702 publication Water Resources Research vol. 33, issue 2 n/a American Geophysical Union (AGU) ppg. 309-319 https://doi.org/10.1029/96WR03137 Digital and/or Hardcopy 199702 publication date Tarboton_1997 Provided techniques used for processing flow conditioned parameter grids (fcpg). U.S. Geological Survey 2023 tabular digital data https://www.sciencebase.gov/catalog/item/57645ff2e4b07657d19ba8e8 Digital and/or Hardcopy 2023 publication date NHDPlus_HR Provided the flow direction grids for flow conditioned parameter grid processing for this hydrography resolution (10 meters). Provided flowlines in HUC 17 that year_of_map and scPDSI values were attributed to. U.S. Environmental Protection Agency 20240617 tabular digital data https://www.epa.gov/waterdata/nhdplus-pacific-northwest-data-vector-processing-unit-17 Digital and/or Hardcopy 20240617 publication date NHDPlusV2 Provided the flow direction grids for processing flow conditioned parameter grids (fcpg) for this hydrography resolution (30 meters). Susan Wherry Audrey M. Martinez Roy Sando Kristin L. Jaeger 2025 tabular digital data https://doi.org/10.5066/P13AB8NW Digital and/or Hardcopy 2004 2016 ground condition PROSPER_2.1 Provided grids representing updated output from the PROSPER model. Emily D Heaston Kristin L Jaeger Jonathan Burnett Steve Wondzell Nathan Chelgren Jason Dunham Sherri Johnson 2024 tabular digital data Jaeger, K.L., Burnett, J., Heaston, E.D., Wondzell, S.M., Chelgren, N., Dunham, J.B., Johnson, S., and Brown, M., 2020, FLOwPER user guide—For collection of FLOw PERmanence field observations: U.S. Geological Survey Open-File Report 2020–1075, 40 p., https://doi.org/10.3133/ofr20201075. https://www.sciencebase.gov/catalog/item/5edea67582ce7e579c6e5845 Digital and/or Hardcopy 20190101 20231231 ground condition FLOwPER_obs Provided the location and year for flow observations in HUC 17. 1. A detailed description of the techniques used to compile the data sets included in this data release are provided in Hafen_et_al_2020, Barnhart_et_al_2020, and Jaeger_et_al_2024. The following steps provide an overview of those techniques. 2024 2. Retrieved flowlines and flow direction grids from NHDPlus_HR for HUC 17. NHDPlus_HR 2024 3. Retrieved flow direction grids from NHDPlusV2 for HUC 17. NHDPlusV2 2024 4. Retrieved Flow/No Flow field observations from FLOwPER_obs for HUC 17. FLOwPER_obs 2024 5. Retrieved grids from WRCC representing self-calibrated Palmer Drought Severity Index (scPDSI) values for HUC 17. WRCC 2024 6. Processed the scPDSI grids from step (5) and used the flow direction grids from step (2) to create flow conditioned (i.e., basin average) parameter grids (fcpg) representing average water year flow conditioned scPDSI (scPDSI_fcpg) values for 1946 – 1999. The 1946-1999 period corresponded to the period represented by the NHDPlus_HR data. NHDPlus_HR 2024 7. Used PNW_quad_extent to identify the estimated year associated with the hydrographic classification streamflow class for each reach in NHDPlus_HR based on the map data of the quad in which each reach was located. PNW_quad_extent 2024 8. Used the results from step (6) to retrieve the scPDSI_fcpg value corresponding to each stream reach in NHDPlus_HR for the estimated year identified in step (7). NHDPlus_HR 2024 9. Joined the results from step (7) to the flowlines in NHDPlus_HR and created individual shapefiles containing the results for each HUC4 watershed within HUC 17. The shapefiles representing each HUC4 watershed are stored as compressed archive files in the child item “National Hydrography Dataset High Resolution Flowlines”. NHDPlus_HR 2024 10. Processed the scPDSI grids from step (5) and used the flow direction grids from (3) to create flow conditioned parameter grids (fcpg) representing average water year flow conditioned scPDSI (scPDSI_fcpg) values for 2004-2016. The 2004-2016 period corresponded to the period represented by the PROSPER_2.1 data, and the scPDSI_fcpgs values represented the cell locations in PROSPER_2.1. The rasters representing each year are stored in the child item “Self-Calibrating Palmer Drought Severity Index Values”. PROSPER_2.1 2024 11. Created a raster representing the mean value from the 2004 to 2016 scPDSI_fcpg grids from step (10) for HUC17. The raster scpdsi_fcpg_30m_2004_2016_MEAN.tif is stored in the child item “Self-Calibrating Palmer Drought Severity Index FLOwPER_obs 2024 12. Processed the scPDSI grids from step (5) and used the flow direction grids from step (2) to create flow conditioned parameter grids representing average water year flow conditioned scPDSI (scPDSI_fcpg) values for 2019-2023. The 2019-2023 period corresponded to the period represented by the FLOwPER_obs data. FLOwPER_obs 2024 13. Used the results from step (12) to retrieve the scPDSI_fcpg value corresponding to each observation in FLOwPER_obs for the year when the observation was made. FLOwPER_obs 2024 14. Joined results from step (13) to the locations in FLOwPER_obs, and created a shapefile containing the results for HUC 17. The shapefile FLOwPER_scPDSI_vector.shp is stored as a compressed archive ("zip") file in the child item “Results from the FLOw PERmanence (FLOwPER) Application”. 2024 Raster Grid Cell 43821 39965 1 Albers Conical Equal Area 29.5 45.5 -96.0 23.0 0.0 0.0 row and column 30.0 30.0 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101004 pnw_self_calibrating_pdsi_data_dictionary.csv Data dictionary for data release. Producer Defined Child Item Name of data release child item Producer Defined The data release child item where the data set is stored Data Set Data set name Producer Defined The data set where the attribute can be found Attribute Name Attribute name Producer Defined The name of each attribute No Data Definition Description of NoData values Producer Defined NA No Data Producer defined Explanation for each type of missing value. Attribute Definition Attribute description Producer Defined A full description of each attribute in the data file Attribute Definition Source The source for the attribute Producer Defined The source for the attribute definition Attribute Value Type The data type for the attribute Producer Defined Codeset Represented by a standard or list of valid values for this attribute Producer defined Enumerated Represented by a set of specific values Producer defined Range Represented a range in numeric values for this attribute Producer defined Codeset - Name The name of the codeset data base Producer Defined - Not applicable Producer defined The data base from where the codeset values were obtained (if applicable) Codeset - Source The source for the codeset values Producer Defined - Not applicable Producer defined The URL where the codeset values can be found (if applicable) Range - Minimum Minimum value for the attribute Producer Defined . Not applicable Producer defined The minimum value across all values that make up this attribute (where applicable) Range - Maximum Maximum value for the attribute Producer Defined . Not applicable Producer defined The maximum value across all values that make up this attribute (where applicable) Range - Units Units for the attribute Producer Defined - Not applicable Producer defined The units that describe this attribute (if applicable) Range - Resolution Resolution for the attribute Producer Defined . Not applicable Producer defined The decimal resolution for the values that make up this attribute (if applicable) Enumerated - Domain Values and Definitions A description of the enumerated values Producer Defined - Not applicable Producer defined The definition for each enumerated value (if applicable) Enumerated - Source of the Definition The source for the enumerated values Producer Defined - Not applicable Producer defined The URL where the enumerated values can be found (if applicable); or "Producer Defined" if generated specifically for this data release (if applicable) The file "pnw_self_calibrating_pdsi_data_dictionary.csv" includes complete descriptions for each of the attributes included in the data release. Not applicable GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P1HCW9MI None 20250220 Daniel R. Wise U.S. Geological Survey Oregon Water Science Center Hydrologist mailing and physical

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Portland OR 97204 US 971-413-9612 dawise@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998