NOAA Global Ensemble Forecast System (GEFS)
Overview
The NOAA Global Ensemble Forecast System (GEFS) is a weather forecast model made up of 21 separate forecasts, or ensemble members. The National Centers for Environmental Prediction (NCEP) started the GEFS to address uncertainty in weather observations, which are used to initialize weather forecast models. The GEFS attempts to quantify the amount of uncertainty in a forecast by generating an ensemble of multiple forecasts from the original observations. With global coverage, GEFS is produced four times a day with weather forecasts going out to 16 days.
Data are retained for 30 days.
This dataset is available on Azure thanks to the NOAA Open Data Dissemination (NODD) Program.
Storage resources
Data are stored primarily in GRIB format.
GRIB files are stored as blobs in the East US Azure region, in the following blob container:
https://noaagefs.blob.core.windows.net/gefs
Within that container, six-hourly forecast folders are named as:
gefs.[date]/[cycle]
dateis the model execution date in YYYYMMDD formatcycleis a six-hourly cycle, one of [00,06,12,18]
Each forecast cycle folder contains three subfolders:
atmoschemwave
File naming conventions vary across subfolders; details for each subfolder follow.
atmos naming conventions
Each atmos folder contains three subfolders with forecast data:
pgrb2ap5pgrb2bp5pgrb2sp25
Example URL:
chem naming conventions
Each chem folder contains two subfolders:
pgrb2ap25pgrb2ap5
Example URL:
wave naming conventions
Each wave folder contains two subfolders:
griddedstation
Example URLs:
https://noaagefs.blob.core.windows.net/gefs/gefs.20210827/06/wave/gridded/gefs.wave.t06z.c00.global.0p25.f003.grib2 https://noaagefs.blob.core.windows.net/gefs/gefs.20210827/06/wave/station/gefs.wave.t06z.bull_tar https://noaagefs.blob.core.windows.net/gefs/gefs.20210827/06/wave/station/gefs.wave.t06z.station_tar
Region information
Large-scale processing is best performed in the East US Azure region, where the data are
Mounting the container
We also provide an API to get read-only SAS (shared access signature) tokens to allow access via, e.g., BlobFuse, which allows you to mount blob containers as drives:
https://planetarycomputer.microsoft.com/api/sas/v1/token/noaagefs/gefs
API documentation is at https://planetarycomputer.microsoft.com/api/sas/v1/docs.
Mounting instructions for Linux are here.
Contact
For questions, please contact the NOAA Open Data Dissemination (NODD) Program Team at nodd@noaa.gov.
Notices
Microsoft provides this dataset on an “as is” basis. Microsoft makes no warranties (express or implied), guarantees, or conditions with respect to your use of the dataset. To the extent permitted under your local law, Microsoft disclaims all liability for any damages or losses - including direct, consequential, special, indirect, incidental, or punitive - resulting from your use of this dataset. This dataset is provided under the original terms that Microsoft received source data.