AIGFS

In December 2025, NOAA announced the release of three AI global forecasting systems.

NOAA deploys new generation of AI-driven global weather models

All three models are available for download in Herbie:

• model="aigfs"

• model="aigefs"

• model="hgefs"

This notebook demonstrates how to download and use AIGFS data using Herbie.

from herbie import Herbie
from herbie.toolbox import EasyMap, pc, ccrs
from herbie import paint

import matplotlib.pyplot as plt

There are two available products:

• product="sfc"

• product="pres"

H = Herbie("2026-02-01", model="aigfs", product="sfc")
H

✅ Found ┊ model=aigfs ┊ product=sfc ┊ 2026-Feb-01 00:00 UTC F00 ┊ GRIB2 @ nomads ┊ IDX @ local

▌▌Herbie AIGFS model sfc product initialized 2026-Feb-01 00:00 UTC F00 ┊ source=nomads

# Show all available sources
H.SOURCES

{'nomads': 'https://nomads.ncep.noaa.gov/pub/data/nccf/com/aigfs/prod/aigfs.20260201/00/model/atmos/grib2/aigfs.t00z.sfc.f000.grib2'}

H.inventory()

	grib_message	start_byte	end_byte	range	reference_time	valid_time	variable	level	forecast_time	search_this
0	1	0	1002703.0	0-1002703	2026-02-01	2026-02-01	UGRD	10 m above ground	anl	:UGRD:10 m above ground:anl:
1	2	1002704	1981711.0	1002704-1981711	2026-02-01	2026-02-01	VGRD	10 m above ground	anl	:VGRD:10 m above ground:anl:
2	3	1981712	2512347.0	1981712-2512347	2026-02-01	2026-02-01	TMP	2 m above ground	anl	:TMP:2 m above ground:anl:
3	4	2512348	NaN	2512348-	2026-02-01	2026-02-01	PRMSL	mean sea level	anl	:PRMSL:mean sea level:anl:

H = Herbie("2026-02-01", model="aigfs", product="pres")
H.inventory()

✅ Found ┊ model=aigfs ┊ product=pres ┊ 2026-Feb-01 00:00 UTC F00 ┊ GRIB2 @ nomads ┊ IDX @ local

	grib_message	start_byte	end_byte	range	reference_time	valid_time	variable	level	forecast_time	search_this
0	1	0	673222.0	0-673222	2026-02-01	2026-02-01	HGT	50 mb	anl	:HGT:50 mb:anl:
1	2	673223	1329174.0	673223-1329174	2026-02-01	2026-02-01	HGT	100 mb	anl	:HGT:100 mb:anl:
2	3	1329175	1993554.0	1329175-1993554	2026-02-01	2026-02-01	HGT	150 mb	anl	:HGT:150 mb:anl:
3	4	1993555	2656655.0	1993555-2656655	2026-02-01	2026-02-01	HGT	200 mb	anl	:HGT:200 mb:anl:
4	5	2656656	3314383.0	2656656-3314383	2026-02-01	2026-02-01	HGT	250 mb	anl	:HGT:250 mb:anl:
...	...	...	...	...	...	...	...	...	...	...
73	74	77577252	78369407.0	77577252-78369407	2026-02-01	2026-02-01	VVEL	600 mb	anl	:VVEL:600 mb:anl:
74	75	78369408	79179487.0	78369408-79179487	2026-02-01	2026-02-01	VVEL	700 mb	anl	:VVEL:700 mb:anl:
75	76	79179488	80019147.0	79179488-80019147	2026-02-01	2026-02-01	VVEL	850 mb	anl	:VVEL:850 mb:anl:
76	77	80019148	80844486.0	80019148-80844486	2026-02-01	2026-02-01	VVEL	925 mb	anl	:VVEL:925 mb:anl:
77	78	80844487	NaN	80844487-	2026-02-01	2026-02-01	VVEL	1000 mb	anl	:VVEL:1000 mb:anl:

78 rows × 10 columns

ds = H.xarray(":TMP:700 mb")

ax = EasyMap(crs=ds.herbie.crs, figsize=[10, 8]).ax
p = ax.pcolormesh(
    ds.longitude,
    ds.latitude,
    ds.t - 273.15,
    transform=pc,
    **paint.NWSTemperature.kwargs2,
)
plt.colorbar(
    p, ax=ax, orientation="horizontal", pad=0.05, **paint.NWSTemperature.cbar_kwargs2
)

ax.set_title(f"{ds.t.GRIB_name} @ {ds.t.isobaricInhPa.item()} hPa", loc="right")
ax.set_title(f"{ds.model.upper()}: {H.product_description}", loc="left")

Text(0.0, 1.0, 'AIGFS: pressure fields, 0.25 degree resolution')

Now, going back to the surface product, just for fun, let’s plot the change in 24-hr sea level pressure

H1 = Herbie("2026-02-01", model="aigfs", product="sfc", fxx=0)
H2 = Herbie("2026-02-01", model="aigfs", product="sfc", fxx=24)

diff = H2.xarray("PRMSL").prmsl - H1.xarray("PRMSL").prmsl

ax = EasyMap(figsize=[8, 8]).ax
p = ax.pcolormesh(
    diff.longitude, diff.latitude, diff, transform=pc, vmax=3000, vmin=-3000, cmap="bwr"
)

plt.colorbar(
    p,
    ax=ax,
    orientation="horizontal",
    pad=0.05,
    shrink=0.8,
)

plt.title("Change in Sea Level Pressure; F24 minus F00")

✅ Found ┊ model=aigfs ┊ product=sfc ┊ 2026-Feb-01 00:00 UTC F00 ┊ GRIB2 @ nomads ┊ IDX @ local
✅ Found ┊ model=aigfs ┊ product=sfc ┊ 2026-Feb-01 00:00 UTC F24 ┊ GRIB2 @ nomads ┊ IDX @ local

Text(0.5, 1.0, 'Change in Sea Level Pressure; F24 minus F00')