ABSTRACT:

A pre-computed cache of daily streamflow used by the Hydro Correlation Tool, a Tethys application for cross-mapping USGS stream gages to NWM v3 and GEOGLOWS v2 reaches. This is a convenience copy of publicly available model output and observations, not original data and not an authoritative source.

Contents: 24,070 reach-series covering 2018-01-01 to 2022-12-31 — GEOGLOWS v2 retrospective (8,309), NWM v3 retrospective (7,462), and USGS daily discharge, parameter 00060 (8,299). Single Apache Parquet file, zstd-compressed. Columns: network, reach_id, start_date, end_date, units, values, dates. 55 rows have empty value arrays — these are reaches the source returned no data for, retained deliberately so downstream users don't re-request them.

Retrieved August 2026. Source datasets may have been revised since; consult the original providers for authoritative values.

Sources and attribution:

GEOGLOWS Hydrological Model Version 2, accessed August 2026 from https://registry.opendata.aws/geoglows-v2 (CC BY 4.0). DOI: https://doi.org/10.1111/jfr3.12859
NOAA National Water Model v3 Retrospective, NOAA/NWS Office of Water Prediction (public domain).
U.S. Geological Survey National Water Information System daily values (public domain).

ABSTRACT:

This resource contains 3 items: A Colab notebook demonstrating how to use the NWPS API and the NWM API through a simple flood warning system; Another Colab notebook that demonstrates the use of the GEOGLOWS API through a similar flood warning system; A PowerPoint that was presented at the 2026 Tethys Platform Summit. All three of these resources were used in a 90 minute workshop meant to familiarize participants with the use of public APIs. These notebooks are fully working and ready to be copied, but users must have access to a NWM API key for full functionality. One can request a key at https://hub.ciroh.org/docs/products/data-management/bigquery-api/ . For further information please see the README document.

Acknowledgements:
This research was supported by the Cooperative Institute for Research to Operations in Hydrology (CIROH) with funding under award NA22NWS4320003 from the NOAA Cooperative Institute Program. The statements, findings, conclusions, and recommendations are those of the author(s) and do not necessarily reflect the opinions of NOAA.