Table of Contents
1. Overview
Hail Sentinel's forecasts, outlooks, and hail-verification data draw on a mix of our own models and third-party sources. This page is the single home for every attribution, license, and non-endorsement notice we owe those sources — some are legal obligations tied to a specific license, others are voluntary transparency about data we use or reference. It is referenced from the site footer and from the methodology notes on our research and product pages.
2. WeatherNext-2 (Google DeepMind)
Anvil's multi-day outlook incorporates WeatherNext-2 forecast data produced by Google DeepMind, used under the Creative Commons Attribution 4.0 International license ("CC BY 4.0"). WeatherNext-2 data is used at a minimum 48-hour initialization age, in accordance with its license terms.
© 2025 DeepMind Technologies Limited's machine learning models used to create the experimental data made available at https://developers.google.com/earth-engine/datasets/catalog/projects_gcp-public-data-weathernext_assets_weathernext_2_0_0 under CC BY 4.0 licence terms. This data is intended for experimental modelling only and is not intended, validated, or approved for real world use.
Contains modified WeatherNext-2 forecast data. Hail Sentinel's outlook is its own product; Google and Google DeepMind do not endorse Hail Sentinel or its forecasts.
3. Copernicus / ECMWF
WeatherNext-2 is derived in part from data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF), as modified by Google DeepMind, and from modified Copernicus Climate Change Service information. In accordance with the license to use Copernicus Products: this page contains modified Copernicus Climate Change Service information; neither the European Commission nor ECMWF is responsible for any use of that information.
4. CoCoRaHS
Hail-verification data used to train and evaluate Anvil includes reports from CoCoRaHS (Community Collaborative Rain, Hail and Snow Network), used under the Creative Commons Attribution 3.0 License, per the CoCoRaHS Data Usage Policy. Data provided by the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS), used under CC BY 3.0.
5. NOAA / National Weather Service
Hail-verification data also includes U.S. National Weather Service (NWS) Local Storm Reports and NOAA Storm Prediction Center (SPC) reports. Per the NWS Disclaimer, this information is a work of the U.S. government and is in the public domain — no attribution is legally required, though we credit it here for transparency. We never reproduce the National Weather Service or NOAA seal, emblem, or wordmark logo anywhere on this site; when we identify these agencies as sources, we do so by name only.
6. Benchmark Baselines
ProbSevere v3 and MESH are named on our research and product pages solely to identify the independent, publicly operated baselines Anvil's detection performance was measured against. ProbSevere is a product of NOAA and the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin–Madison, obtained via NOAA's public data feeds; MESH is a NOAA product.
7. Our Forecasts Are Our Own
Anvil's probabilities, sizes, alert decisions, and outlooks are produced by Hail Sentinel's own models. They are not produced by, or attributable to, any third-party data provider, and they are not a substitute for official National Weather Service warnings.
8. Non-Endorsement
Hail Sentinel is not affiliated with, endorsed by, or sponsored by Google, Google DeepMind, NOAA, the National Weather Service, the Storm Prediction Center, CIMSS, the University of Wisconsin–Madison, ECMWF, or CoCoRaHS.
9. Contact
For questions about the data sources or licenses on this page:
Icarus, Inc., d/b/a Hail Sentinel
Legal: legal@hailsentinel.com