Weather analysis from the Global Forecast System (GFS) operated by NOAA NWS NCEP.

| | |
|-------|-------|
| Spatial domain | Global |
| Spatial resolution | 0.25 degrees (~20km) |
| Time domain | 2021-05-01 00:00:00 UTC to Present |
| Time resolution | 1 hour |

The Global Forecast System (GFS) is a National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) weather forecast model that generates data for dozens of atmospheric and land-soil variables, including temperatures, winds, precipitation, soil moisture, and atmospheric ozone concentration. The system couples four separate models (atmosphere, ocean model, land/soil model, and sea ice) that work together to depict weather conditions.

This analysis dataset is an archive of the model's best estimate of past weather. It is created by concatenating the first few hours of each historical forecast to provide a dataset with dimensions time, latitude, and longitude.

_Don't see what you're looking for or have a question? Contact feedback@dynamical.org._


## Examples

* [Quickstart (Github)](https://github.com/dynamical-org/notebooks/blob/main/noaa-gfs-analysis.ipynb)
* [Quickstart (Colab)](https://colab.research.google.com/github/dynamical-org/notebooks/blob/main/noaa-gfs-analysis.ipynb)



## Dimensions

| dimension | min | max | units |
|-------|-------|-------|-------|
| **latitude** | -90 | 90 | degree_north |
| **longitude** | -180 | 179.75 | degree_east |
| **time** | 2021-05-01T00:00:00Z |  | seconds since 1970-01-01 |


## Variables

| variable | units | dimensions |
|-------|-------|-------|
| **categorical_freezing_rain_surface**<br>`cfrzr`<br>Categorical freezing rain<br>Presence/absence over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). 0=no; 1=yes. | 1 | time × latitude × longitude |
| **categorical_ice_pellets_surface**<br>`cicep`<br>Categorical ice pellets<br>Presence/absence over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). 0=no; 1=yes. | 1 | time × latitude × longitude |
| **categorical_rain_surface**<br>`crain`<br>Categorical rain<br>Presence/absence over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). 0=no; 1=yes. | 1 | time × latitude × longitude |
| **categorical_snow_surface**<br>`csnow`<br>Categorical snow<br>Presence/absence over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). 0=no; 1=yes. | 1 | time × latitude × longitude |
| **downward_long_wave_radiation_flux_surface**<br>`sdlwrf`<br>Surface downward long-wave radiation flux<br>Average over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). | W m-2 | time × latitude × longitude |
| **downward_short_wave_radiation_flux_surface**<br>`sdswrf`<br>Surface downward short-wave radiation flux<br>Average over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). | W m-2 | time × latitude × longitude |
| **geopotential_height_cloud_ceiling**<br>`gh`<br>Geopotential height | m | time × latitude × longitude |
| **maximum_temperature_2m**<br>`tmax`<br>Maximum temperature<br>Maximum over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). | degree_Celsius | time × latitude × longitude |
| **minimum_temperature_2m**<br>`tmin`<br>Minimum temperature<br>Minimum over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). | degree_Celsius | time × latitude × longitude |
| **percent_frozen_precipitation_surface**<br>`cpofp`<br>Percent frozen precipitation | percent | time × latitude × longitude |
| **precipitable_water_atmosphere**<br>`pwat`<br>Precipitable water | kg m-2 | time × latitude × longitude |
| **precipitation_surface**<br>`prate`<br>Precipitation rate<br>Average precipitation rate since the previous forecast step. Units equivalent to mm/s. | kg m-2 s-1 | time × latitude × longitude |
| **pressure_reduced_to_mean_sea_level**<br>`prmsl`<br>Pressure reduced to MSL | Pa | time × latitude × longitude |
| **pressure_surface**<br>`sp`<br>Surface pressure | Pa | time × latitude × longitude |
| **relative_humidity_2m**<br>`2r`<br>2 metre relative humidity | percent | time × latitude × longitude |
| **temperature_2m**<br>`2t`<br>2 metre temperature | degree_Celsius | time × latitude × longitude |
| **total_cloud_cover_atmosphere**<br>`tcc`<br>Total cloud cover<br>Average over the previous 1-6 hours, reset every 6-hour forecast step (00Z, 06Z, 12Z, 18Z). | percent | time × latitude × longitude |
| **wind_u_100m**<br>`100u`<br>100 metre U wind component | m s-1 | time × latitude × longitude |
| **wind_u_10m**<br>`10u`<br>10 metre U wind component | m s-1 | time × latitude × longitude |
| **wind_v_100m**<br>`100v`<br>100 metre V wind component | m s-1 | time × latitude × longitude |
| **wind_v_10m**<br>`10v`<br>10 metre V wind component | m s-1 | time × latitude × longitude |


Contact feedback@dynamical.org to request additional variables.

## Details

### License
Dataset licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).

### Attribution and citation
_NOAA NWS NCEP GFS data processed by dynamical.org from NOAA Open Data Dissemination archives._

Or _NOAA GFS from dynamical.org._

[DOI: 10.5281/zenodo.18777399](https://doi.org/10.5281/zenodo.18777399)

### Construction

GFS starts a new model run every 6 hours and dynamical.org has created this analysis by concatenating the first 6 hours of each forecast along the time dimension.

### Source

The source grib files this archive is constructed from are provided by [NOAA Open Data Dissemination (NODD)](https://www.noaa.gov/information-technology/open-data-dissemination) and accessed from the [AWS Open Data Registry](https://registry.opendata.aws/noaa-gfs-bdp-pds/). Operational data is additionally accessed from [NOAA NOMADS](https://nomads.ncep.noaa.gov/).

### Storage

Storage for this dataset is generously provided by [Source Cooperative](https://source.coop/), a [Radiant Earth](https://radiant.earth/) initiative. Icechunk storage generously provided by [AWS Open Data](https://aws.amazon.com/opendata/).

### Chunks &amp; shards

This dataset is stored in [Zarr](https://zarr.dev/) format, which splits each variable into a grid of **chunks** — the smallest unit read from storage. Chunks are grouped into larger **shards** (the objects actually written to storage), which keeps the object count manageable for long-archive datasets. When possible, aligning your reads with this dataset&#39;s chunk grid can significantly improve data access speed.

The element count and coordinate span of this dataset:

| dimension | chunk | shard |
|---|---|---|
| time | 1440 (60 days) | 1440 (60 days) |
| latitude | 50 (12.5°) | 400 (100°) |
| longitude | 50 (12.5°) | 400 (100°) |
| **uncompressed** | 13.7 MiB | 878.9 MiB |

The same values are published in the `dynamical-org:chunking` field of this dataset&#39;s [STAC collection metadata](https://stac.dynamical.org/catalog.json).

### Compression

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. The exact number of rounded bits can be found in our [reformatting code](https://github.com/dynamical-org/reformatters/blob/main/src/reformatters/noaa/gfs/analysis/template_config.py).

### Related dataset

[NOAA GEFS analysis](/catalog/noaa-gefs-analysis/) provides a much longer historical record.