Extreme Flood, Atmospheric River Presence, and Basin Characteristic Data for a Study of Peak Streamflow Special Conditions in Alaska

This data release contains input data and results for an investigation of special conditions for peak streamflow and extreme floods for USGS streamgages in Alaska. Special conditions can include data-collection conditions, basin conditions, flood-generating mechanisms, or other information and can be critical for informing hydrologic analyses such as flood frequency analysis. The dataset contains three tables: (1) table of peak flows identified as extreme floods in Alaska through water year 2022, selected associated special conditions and climate information, and results of an assessment of flood-generating mechanisms, (2) a table of atmospheric river presence or absence data for Alaska for 1980-2019 that were used to assess peak-flow conditions, and (3) a table of input data and results for a drainage area-precipitation cluster analysis for 455 streamgages in Alaska.