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NOAA Global Ensemble Forecast System (GEFS) Re-forecast

agriculture climate meteorological weather


NOAA has generated a multi-decadal reanalysis and reforecast data set to accompany the next-generation version of its ensemble prediction system, the Global Ensemble Forecast System, version 12 (GEFSv12). Accompanying the real-time forecasts are “reforecasts” of the weather, that is, retrospective forecasts spanning the period 2000-2019. These reforecasts are not as numerous as the real-time data; they were generated only once per day, from 00 UTC initial conditions, and only 5 members were provided, with the following exception. Once weekly, an 11-member reforecast was generated, and these extend in lead time to +35 days.

Update Frequency

Re-forecasts do not adhere to an update frequency.


Open Data. There are no restrictions on the use of this data.


Managed By

See all datasets managed by NOAA.


For any questions regarding data delivery or any general questions regarding the NOAA Open Data Dissemination (NODD) Program, email the NODD Team at
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How to Cite

NOAA Global Ensemble Forecast System (GEFS) Re-forecast was accessed on DATE from

Usage Examples


Resources on AWS

  • Description
    GEFS Re-forecast in Grib2 Format
    Resource type
    S3 Bucket
    Amazon Resource Name (ARN)
    AWS Region
    AWS CLI Access (No AWS account required)
    aws s3 ls --no-sign-request s3://noaa-gefs-retrospective/
    Browse Bucket

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