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NOAA makes the AI GFS family operational (AIGFS, AIGEFS, HGEFS)

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graphcast gfs gefsatmos

NCEP announced operational rollout of AIGFS, AIGEFS, and HGEFS effective Dec 17, 2025 (12Z), delivering GraphCast-based deterministic and ensemble forecasts on NOMADS.

NOAA/NCEP announced that three new AI-driven global model feeds are operational: AIGFS (deterministic), AIGEFS (ensemble), and HGEFS (hybrid ensemble). The implementation date is December 17, 2025, starting with the 12Z cycle.

What is new

  • AIGFS v1.0: global deterministic AI model based on Google DeepMind's GraphCast.
  • AIGEFS v1.0: a 31-member AI ensemble using the same core.
  • HGEFS v1.0: a 62-member hybrid ensemble that combines AIGEFS with the operational GEFSv12.

NCEP ran an evaluation period starting December 9, 2025, and made the data public for assessment before operational rollout.

Data access notes

  • Operational data are published via NOMADS only (no FTP).
  • Evaluation paths were under /com/aigfs/para/, /com/aigefs/para/, /com/hgefs/para/.
  • Operational paths are under /com/aigfs/prod/, /com/aigefs/prod/, /com/hgefs/prod/.

Why it matters

This brings AI-driven deterministic and ensemble guidance into NOAA's operational stack. For users, it means new sources of global guidance that can be compared against GFS/GEFS for skill, spread, and uncertainty.

What this means for GribStream users

GribStream already supports core global models like GFS, GEFS, and the AI-powered GraphCast GFS. We plan to add AIGFS/AIGEFS/HGEFS as soon as they become available through the AWS Open Data program. If you rely on AI-driven global ensembles, this is an important new signal to watch.

Update, April 26, 2026: GribStream now supports the operational AIGFS deterministic gridded forecast feed as AIGFS Surface and AIGFS Pressure.

Update, May 7, 2026: The AWS GraphCastGFS/Open Data bucket is now branded as NOAA EAGLE and current AIGFS and AIGEFS forecast data are visible in s3://noaa-nws-graphcastgfs-pds/. See the follow-up: NOAA EAGLE now carries current AIGFS and AIGEFS forecasts in AWS. HGEFS was not visible in the same S3 check, so its availability should still be tracked through the operational NOMADS feed unless current AWS objects appear.

Update, May 8, 2026: GribStream now indexes AIGFS directly from NOAA EAGLE S3 and supports the AIGEFS member products as AIGEFS Surface and AIGEFS Pressure.

Sources

Related models

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