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

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.

Sources

• NWS Service Change Notice 25-89 (Dec 9, 2025): https://www.weather.gov/media/notification/pdf_2025/scn25-89_AIGFS_AIGEFS_and_HGEFS.pdf