# NOAA GEFS forecast, 35 day - dynamical.org zarr View the latest documentation at https://dynamical.org/catalog/noaa-gefs-forecast-35-day/. | | | | - | - | | **Spatial domain** | Global | | **Spatial resolution** | 0-240 hours: 0.25 degrees (\~20km), 243-840 hours: 0.5 degrees (\~40km) | | **Time domain** | Forecasts initialized 2020-10-01 00:00:00 UTC to Present | | **Time resolution** | Forecasts initialized every 24 hours. | | **Forecast domain** | Forecast lead time 0-840 hours (0-35 days) ahead | | **Forecast resolution** | Forecast step 0-240 hours: 3 hourly, 243-840 hours: 6 hourly | ### Data Access ``` https://data.dynamical.org/noaa/gefs/forecast/latest.zarr?email=optional@email.com ``` *Email optional. Providing your email as a query param helps us understand usage and impact to keep dynamical.org supported for the long-term. For catalog updates follow [here](https://dynamical.org/updates).* ### Description The Global Ensemble Forecast System (GEFS) is a National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) weather forecast model. GEFS creates 31 separate forecasts (ensemble members) to describe the range of forecast uncertainty. This dataset is an archive of past and present GEFS forecasts. Forecasts are identified by an initialization time (`init_time`) denoting the start time of the model run as well as by the `ensemble_member`. Each forecast has a 3-hourly forecast step along the `lead_time` dimension. This dataset contains only the 00 hour UTC initialization times which produce the full-length, 35-day forecast. The data values in this dataset have been rounded in their binary floating point representation to improve compression. See [Klöwer et al. 2021](https://www.nature.com/articles/s43588-021-00156-2) for more information on this approach. Storage for this dataset is generously provided by [Source Cooperative](https://source.coop/), a [Radiant Earth](https://radiant.earth/) initiative. ## Dimensions | Dimension | Min | Max | Units | | -------------------- | ------------------- | ---------------- | ------------------------ | | **init\_time** | 2020-10-01T00:00:00 | Present | seconds since 1970-01-01 | | **ensemble\_member** | 0 | 30 | realization | | **lead\_time** | 0 days 00:00:00 | 35 days 00:00:00 | seconds | | **latitude** | -90 | 90 | degrees\_north | | **longitude** | -180 | 179.75 | degrees\_east | ## Variables | Variable | Units | Dimensions | |--------------------------------------------------|---------------------|---------------------------------------------------------| | **categorical_freezing_rain_surface** | 0=no; 1=yes | init_time × ensemble_member × lead_time × latitude × longitude | | **categorical_freezing_rain_surface_avg** | 0=no; 1=yes | init_time × lead_time × latitude × longitude | | **categorical_ice_pellets_surface** | 0=no; 1=yes | init_time × ensemble_member × lead_time × latitude × longitude | | **categorical_ice_pellets_surface_avg** | 0=no; 1=yes | init_time × lead_time × latitude × longitude | | **categorical_rain_surface** | 0=no; 1=yes | init_time × ensemble_member × lead_time × latitude × longitude | | **categorical_rain_surface_avg** | 0=no; 1=yes | init_time × lead_time × latitude × longitude | | **categorical_snow_surface** | 0=no; 1=yes | init_time × ensemble_member × lead_time × latitude × longitude | | **categorical_snow_surface_avg** | 0=no; 1=yes | init_time × lead_time × latitude × longitude | | **downward_long_wave_radiation_flux_surface** | W/(m^2) | init_time × ensemble_member × lead_time × latitude × longitude | | **downward_long_wave_radiation_flux_surface_avg**| W/(m^2) | init_time × lead_time × latitude × longitude | | **downward_short_wave_radiation_flux_surface** | W/(m^2) | init_time × ensemble_member × lead_time × latitude × longitude | | **downward_short_wave_radiation_flux_surface_avg**| W/(m^2) | init_time × lead_time × latitude × longitude | | **expected_forecast_length** | seconds | init_time | | **geopotential_height_cloud_ceiling** | gpm | init_time × ensemble_member × lead_time × latitude × longitude | | **ingested_forecast_length** | seconds | init_time × ensemble_member | | **maximum_temperature_2m** | C | init_time × ensemble_member × lead_time × latitude × longitude | | **maximum_temperature_2m_avg** | C | init_time × lead_time × latitude × longitude | | **minimum_temperature_2m** | C | init_time × ensemble_member × lead_time × latitude × longitude | | **minimum_temperature_2m_avg** | C | init_time × lead_time × latitude × longitude | | **percent_frozen_precipitation_surface** | % | init_time × ensemble_member × lead_time × latitude × longitude | | **precipitable_water_atmosphere** | kg/(m^2) | init_time × ensemble_member × lead_time × latitude × longitude | | **precipitable_water_atmosphere_avg** | kg/(m^2) | init_time × lead_time × latitude × longitude | | **precipitation_surface** | kg/(m^2) | init_time × ensemble_member × lead_time × latitude × longitude | | **precipitation_surface_avg** | kg/(m^2) | init_time × lead_time × latitude × longitude | | **pressure_reduced_to_mean_sea_level** | Pa | init_time × ensemble_member × lead_time × latitude × longitude | | **pressure_reduced_to_mean_sea_level_avg** | Pa | init_time × lead_time × latitude × longitude | | **pressure_surface** | Pa | init_time × ensemble_member × lead_time × latitude × longitude | | **pressure_surface_avg** | Pa | init_time × lead_time × latitude × longitude | | **relative_humidity_2m** | % | init_time × ensemble_member × lead_time × latitude × longitude | | **relative_humidity_2m_avg** | % | init_time × lead_time × latitude × longitude | | **temperature_2m** | C | init_time × ensemble_member × lead_time × latitude × longitude | | **temperature_2m_avg** | C | init_time × lead_time × latitude × longitude | | **total_cloud_cover_atmosphere** | % | init_time × ensemble_member × lead_time × latitude × longitude | | **total_cloud_cover_atmosphere_avg** | % | init_time × lead_time × latitude × longitude | | **valid_time** | seconds since 1970-01-01 | init_time × lead_time | | **wind_u_100m** | m/s | init_time × ensemble_member × lead_time × latitude × longitude | | **wind_u_10m** | m/s | init_time × ensemble_member × lead_time × latitude × longitude | | **wind_u_10m_avg** | m/s | init_time × lead_time × latitude × longitude | | **wind_v_100m** | m/s | init_time × ensemble_member × lead_time × latitude × longitude | | **wind_v_10m** | m/s | init_time × ensemble_member × lead_time × latitude × longitude | | **wind_v_10m_avg** | m/s | init_time × lead_time × latitude × longitude | Don't see what you're looking for? Let us know at [feedback@dynamical.org](mailto\:feedback@dynamical.org). ## Examples [Open notebook in GitHub](https://github.com/dynamical-org/notebooks/blob/main/noaa-gefs-forecast-35-day.ipynb) [Open notebook in Colab](https://colab.research.google.com/github/dynamical-org/notebooks/blob/main/noaa-gefs-forecast-35-day.ipynb) ```python import xarray as xr ds = xr.open_zarr("https://data.dynamical.org/noaa/gefs/forecast-35-day/latest.zarr?email=optional@email.com") ds['temperature_2m'].sel(init_time="2025-01-01T00", latitude=0, longitude=0).max().compute() ```