Sources and licences
- NRCS SNOTEL snow pillows. Snow data: USDA NRCS National Water and Climate Center, Air and Water Database (AWDB); history via the source.coop nthh/snotel mirror (CC0). Provisional data: NRCS data are subject to revision and are released on condition that neither the NRCS nor the United States Government may be held liable for any damages resulting from their use. licence
- UC Berkeley Central Sierra Snow Lab (manual). Central Sierra Snow Laboratory, UC Berkeley: Osterhuber, R. and Schwartz, A., daily observations for winters 1970–71 to 2018–19, doi:10.6078/D1941T (CC0). licence
- Climate indices (CPC, NCEI, PSL). Climate indices: NOAA Climate Prediction Center, NOAA NCEI and NOAA PSL (US public domain). licence
- gridMET daily precipitation and temperature. gridMET, Climatology Lab: Abatzoglou, J. T. (2013), Int. J. Climatol., doi:10.1002/joc.3413. licence
- USGS 3DEP 1 arc-second DEM. Terrain: USGS 3D Elevation Program (3DEP) 1 arc-second DEM (US public domain). licence
- ERA5 monthly reanalysis (SST, Z500, IVT). Generated using or contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horanyi, A., Munoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., Thepaut, J-N. (2023): ERA5 monthly averaged data on single levels from 1940 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS), DOI: 10.24381/cds.f17050d7; and ERA5 monthly averaged data on pressure levels from 1940 to present, DOI: 10.24381/cds.6860a573. Licence: CC-BY 4.0 (https://spdx.org/licenses/CC-BY-4.0). licence
- ECMWF SEAS5 seasonal forecast. Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. ECMWF SEAS5 (system 51) from: Copernicus Climate Change Service, Climate Data Store (2018): Seasonal forecast monthly statistics on single levels. Copernicus Climate Change Service (C3S) Climate Data Store (CDS), DOI: 10.24381/cds.68dd14c3. Licence: CC-BY 4.0. This site turned the data into anomalies and snow amounts for its area. licence
- NMME seasonal forecasts (7 models). NMME data: Kirtman, B. P., and co-authors (2014), The North American Multimodel Ensemble: Phase-1 seasonal-to-interannual prediction; Phase-2 toward developing intraseasonal prediction, Bull. Amer. Meteor. Soc., 95(4), 585-601, doi:10.1175/BAMS-D-12-00050.1. The NMME project and data dissemination is supported by NOAA, NSF, NASA and DOE. We acknowledge the help of NCEP, IRI and NCAR personnel in creating, updating and maintaining the NMME archive, and thank the modelling groups (ECCC, NASA GMAO, NOAA GFDL, NOAA NCEP, NCAR, University of Miami) for their model output. The NMME average and all values here are computed by this site; they are not NOAA products and imply no NOAA endorsement. licence
- NOAA CPC official 3-month outlooks. NOAA Climate Prediction Center official 3-month outlooks (US public domain). The odds are CPC's; this site placed them on 0.25° cells and computed the area odds and scores, so these are not official NOAA or NWS material and imply no NOAA or NWS endorsement. licence
- Software, fonts and icons. Their licences