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NOAA EAGLE now carries current AIGFS and AIGEFS forecasts in AWS

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NOAA's EAGLE/Open Data bucket now contains current AIGFS deterministic and AIGEFS ensemble forecast data, improving access and retention prospects for AI global guidance.

NOAA's AI forecast distribution is no longer a clean split between old GraphCastGFS files in AWS and operational AIGFS/AIGEFS/HGEFS files on NOMADS.

The AWS registry page for noaa-nws-graphcastgfs-pds now labels the dataset NOAA EAGLE and says AIGFS and AIGEFS are the operational replacements for EAGLE SOLO and EAGLE Ensemble. The bucket itself now contains current AIGFS deterministic and AIGEFS ensemble forecast data.

What changed

A May 7, 2026 no-sign AWS S3 check confirmed current AIGFS prefixes at the bucket root:

s3://noaa-nws-graphcastgfs-pds/aigfs.20260416/
s3://noaa-nws-graphcastgfs-pds/aigfs.20260507/

The May 7 AIGFS prefix contains forecast cycles in the same operational-style layout documented by NWS:

s3://noaa-nws-graphcastgfs-pds/aigfs.20260507/00/model/atmos/grib2/aigfs.t00z.pres.f000.grib2
s3://noaa-nws-graphcastgfs-pds/aigfs.20260507/00/model/atmos/grib2/aigfs.t00z.sfc.f000.grib2

The same bucket also contains current AIGEFS ensemble member prefixes under EAGLE_ensemble/. The May 7 00, 06, and 12 cycles were visible during the check, and the 00 cycle showed members mem000 through mem030:

s3://noaa-nws-graphcastgfs-pds/EAGLE_ensemble/aigefs.20260507/00/mem000/model/atmos/grib2/aigefs.t00z.pres.f000.grib2
s3://noaa-nws-graphcastgfs-pds/EAGLE_ensemble/aigefs.20260507/00/mem030/model/atmos/grib2/aigefs.t00z.sfc.f384.grib2

At the time of this check, a current hgefs.20260507/ prefix was not visible at the bucket root or under EAGLE_ensemble/. HGEFS is still documented by NWS as an operational NOMADS product, so HGEFS availability should be tracked separately from the AIGFS and AIGEFS objects visible in this AWS bucket.

The science context

NWS Service Change Notice 25-89 made AIGFS v1.0, AIGEFS v1.0, and HGEFS v1.0 operational on December 17, 2025 at the 1200 UTC cycle.

AIGFS is NOAA's global deterministic AI forecast based on Google DeepMind's GraphCast. AIGEFS runs the same model family as a 31-member ensemble, which makes it useful for spread, uncertainty, and scenario comparison. HGEFS combines AIGEFS with GEFSv12 into a 62-member hybrid ensemble.

NOAA documents AIGFS and AIGEFS at 0.25 degree global resolution, four cycles per day, and 6-hour forecast steps out to 384 hours. HGEFS is documented out to 240 hours.

The AWS registry page now frames the old GraphCastGFS bucket as NOAA EAGLE. It says EAGLE SOLO v1 ended at 18Z on December 18, 2025, EAGLE Ensemble v1 ended at 18Z on December 17, 2025, and future EAGLE development forecasts will continue in the bucket.

For users, this is best read as a mixed AI-forecast distribution point:

  • historical and development EAGLE/GraphCastGFS content
  • current AIGFS deterministic forecasts
  • current AIGEFS ensemble-member forecasts
  • no confirmed HGEFS S3 prefix from this check

Why this matters

Current AIGFS and AIGEFS data in AWS changes the practical value of the AI-GFS family. It can support longer retention and easier side-by-side comparison with GFS, GEFS, and IFS than a short rolling NOMADS window alone.

For forecast users, the interesting questions are scientific and operational:

  • Where does AIGFS agree or disagree with physics-based GFS?
  • Does AIGEFS spread add useful uncertainty information beyond deterministic AI guidance?
  • How often do the AI ensemble members capture alternative medium-range scenarios?
  • Can AI-GFS guidance become part of routine model comparison instead of a separate experiment?

Why this matters for GribStream

GribStream serves deterministic AIGFS as AIGFS Surface and AIGFS Pressure.

The current AWS data matters because it can make AI-GFS access more durable. For customers comparing model guidance, that means AIGFS can become more useful for historical backtests, live-vs-archive comparisons, and medium-range verification instead of only short-window forecast checks.

Update, May 8, 2026: GribStream now indexes AIGFS directly from this AWS bucket and supports AIGEFS as AIGEFS Surface and AIGEFS Pressure. See the follow-up: GribStream moves AIGFS to NOAA EAGLE S3 and adds AIGEFS.

AIGFS, AIGEFS, EAGLE, and historical GraphCastGFS remain related but distinct sources of guidance. If an upstream GraphCastGFS or EAGLE development feed stops updating, GribStream would stop receiving new forecasts for that feed. Historical forecasts can remain available for as long as the underlying AWS Open Data objects remain available.

Sources

Related models

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