Catalog > ECMWF AIFS Single forecast > Validation report

ECMWF AIFS Single forecast validation report

This dataset validation report plots a sample of values from the ECMWF AIFS Single forecast dataset over time and across space, comparing where possible to a previously validated reference dataset. It also reports the quantity of unavailable values and their associated timestamps. These analyses are one layer of a multi-layered dataset validation process we perform at dynamical.org and also provide users a preview of the dataset contents.

Report generation start time: 2026-08-19T14:42:08 UTC

Summary

This dataset has been reviewed and is ready for use. Two things are worth knowing before you use it, both described under Review notes: five variables begin partway through the archive, and one forecast is missing four of its lead times.

What looks good

Geometry and coordinates are correct on every variable. The declared global 0.25° latitude/longitude grid, north at the top, longitudes running −180° to 179.75° with no seam or shift, and coastlines and terrain in the right places.
Every field is in its stated units with physically plausible values. Temperatures in degrees Celsius, pressures in pascals, geopotential heights in metres nesting correctly (925 hPa below 850 hPa below 500 hPa), winds in metres per second, precipitation in kilograms per square metre per second, radiation in watts per square metre, cloud cover in percent. No missing-data sentinel values and no visible quantization artifacts.
Close agreement with the reference archive. Where the NOAA GEFS analysis carries the same field, the AIFS values track it in both the maps and the time series. As an AI model AIFS is visibly smoother, with slightly less extreme minima and maxima.
Forecast physics behave as expected. Solar radiation peaks at the correct local hour and is zero through the night, cloud cover varies inversely with it, and the precipitation and radiation accumulators convert to non-negative rates with no spikes at particular lead times.
No unit or scale discontinuities across the whole record. This includes the 2025-02-24 change of source feed, where precipitation switches from metres to millimetres upstream and is rescaled here.

Review notes

Unavailable data

Five variables begin at the 2025-02-24 06:00 UTC forecast rather than at the start of the archive: the 100-metre wind components, surface downward long-wave and short-wave radiation flux, and total cloud cover. They are complete from that forecast onward. The other twelve variables span the full archive from 2024-04-01.
Four lead times of the 2025-01-21 06:00 UTC forecast are missing from the source: hours 0, 12, 192 and 270. Precipitation is also missing at hours 18, 198 and 276 — the step following each of hours 12, 192 and 270 — because it is a rate measured over the preceding step. The rest of that forecast is intact.

Datasets

Role	Name	ID	Version	URL
Validation	ECMWF AIFS Single forecast	`ecmwf-aifs-single-forecast`	`v0.1.0`	`s3://us-west-2.opendata.source.coop/dynamical/ecmwf-aifs-single-forecast/v0.1.0.zarr`
Reference	NOAA GEFS analysis	`noaa-gefs-analysis`	`0.1.2`	`s3://dynamical-noaa-gefs/noaa-gefs-analysis/v0.1.2.icechunk/`

Run parameters

Parameter	Value
Validation dataset type	forecast
Validation time range	init_time 2024-04-01T00:00 → 2026-08-19T06:00
Reference time range	time 2000-01-01T00:00 → 2026-08-19T06:00
Point 1	lat=62.5000, lon=-124.5000
Point 2	lat=-48.5000, lon=163.5000
Spatial comparison time	init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)
Timeseries period	init=2026-07-15T00:00

Availability

The plot below shows the availability of each variable over time — light red marks unavailable data, dark green marks present data.

availability heatmap

Variable	Complete positions	Incomplete %	First incomplete	Last incomplete
`dew_point_temperature_2m`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`downward_long_wave_radiation_flux_surface`	2165/3482	37.82%	2024-04-01T00:00	2025-02-24T00:00
`downward_short_wave_radiation_flux_surface`	2165/3482	37.82%	2024-04-01T00:00	2025-02-24T00:00
`geopotential_height_500hpa`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`geopotential_height_850hpa`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`geopotential_height_925hpa`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`precipitation_surface`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`pressure_reduced_to_mean_sea_level`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`pressure_surface`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`temperature_2m`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`temperature_850hpa`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`temperature_925hpa`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`total_cloud_cover_atmosphere`	2165/3482	37.82%	2024-04-01T00:00	2025-02-24T00:00
`wind_u_100m`	2165/3482	37.82%	2024-04-01T00:00	2025-02-24T00:00
`wind_u_10m`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00
`wind_v_100m`	2165/3482	37.82%	2024-04-01T00:00	2025-02-24T00:00
`wind_v_10m`	3481/3482	0.03%	2025-01-21T06:00	2025-01-21T06:00

Unavailable timestamps: unavailable_timestamps.txt

Per-variable details

`dew_point_temperature_2m`

Metadata

Field	Value
units	`degree_Celsius`
long_name	2 metre dewpoint temperature
short_name	2d
standard_name	dew_point_temperature
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-35.92	-6.644	3.67	11.86
P2	2.759	6.801	2.737	11.68

Spatial — init=2026-07-15T00:00, lead=126h (reference not available)

Source	min	mean	max
Validation	-79.5	4.056	29.62

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	3.203	8.715	13.69
P2 Validation	-2.156	4.631	9.25

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

dew_point_temperature_2m — full-period value time series

dew_point_temperature_2m — spatial comparison

dew_point_temperature_2m — time series comparison

dew_point_temperature_2m — availability over append dim

`downward_long_wave_radiation_flux_surface`

Metadata

Field	Value
units	`W m-2`
long_name	Surface downward long-wave radiation flux
short_name	sdlwrf
standard_name	surface_downwelling_longwave_flux_in_air
step_type	avg
comment	Average flux since the previous forecast step.

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	150.4	256.6	23.71	341
P2	290.3	319.7	21.8	356.6

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	44	321.6	466
Reference	52	314.1	476

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	276	319.6	350
P1 Reference	268	323	376
P2 Validation	253	307.2	344
P2 Reference	239	300.4	348

Availability — 2165 of 3482 positions complete (incomplete 2024-04-01T00:00 → 2025-02-24T00:00); nulls P1 79020/208920, P2 79020/208920

downward_long_wave_radiation_flux_surface — full-period value time series

downward_long_wave_radiation_flux_surface — spatial comparison

downward_long_wave_radiation_flux_surface — time series comparison

downward_long_wave_radiation_flux_surface — availability over append dim

`downward_short_wave_radiation_flux_surface`

Metadata

Field	Value
units	`W m-2`
long_name	Surface downward short-wave radiation flux
short_name	sdswrf
standard_name	surface_downwelling_shortwave_flux_in_air
step_type	avg
comment	Average flux since the previous forecast step.

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	5.359	139.9	138.2	281.1
P2	25.4	110.9	123.2	284.8

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	0	155.1	880
Reference	0	164.1	900

Temporal — init=2026-07-15T00:00

Source	mean	max
P1 Validation	237.5	688
P1 Reference	242.6	756
P2 Validation	38.53	188
P2 Reference	40.41	312

Availability — 2165 of 3482 positions complete (incomplete 2024-04-01T00:00 → 2025-02-24T00:00); nulls P1 79020/208920, P2 79020/208920

downward_short_wave_radiation_flux_surface — full-period value time series

downward_short_wave_radiation_flux_surface — spatial comparison

downward_short_wave_radiation_flux_surface — time series comparison

downward_short_wave_radiation_flux_surface — availability over append dim

`geopotential_height_500hpa`

Metadata

Field	Value
units	`m`
long_name	Geopotential height
short_name	gh
standard_name	geopotential_height
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	5112	5459	67.09	5766
P2	5275	5518	103.3	5718

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	4618	5587	5976
Reference	4608	5576	5982

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	5538	5669	5790
P1 Reference	5524	5664	5814
P2 Validation	5228	5450	5610
P2 Reference	5162	5464	5614

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

geopotential_height_500hpa — full-period value time series

geopotential_height_500hpa — spatial comparison

geopotential_height_500hpa — time series comparison

geopotential_height_500hpa — availability over append dim

`geopotential_height_850hpa`

Metadata

Field	Value
units	`m`
long_name	Geopotential height
short_name	gh
standard_name	geopotential_height
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	1259	1412	53.86	1528
P2	1235	1410	74.09	1529

Spatial — init=2026-07-15T00:00, lead=126h (reference not available)

Source	min	mean	max
Validation	878.8	1422	1638

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	1374	1450	1560
P2 Validation	1252	1405	1530

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

geopotential_height_850hpa — full-period value time series

geopotential_height_850hpa — spatial comparison

geopotential_height_850hpa — time series comparison

geopotential_height_850hpa — availability over append dim

`geopotential_height_925hpa`

Metadata

Field	Value
units	`m`
long_name	Geopotential height
short_name	gh
standard_name	geopotential_height
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	599.9	735.2	56.59	833.5
P2	552.7	724.9	74.14	844.4

Spatial — init=2026-07-15T00:00, lead=126h (reference not available)

Source	min	mean	max
Validation	246.9	725.7	930.5

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	663.5	735.2	848.8
P2 Validation	570.8	726.4	851.2

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

geopotential_height_925hpa — full-period value time series

geopotential_height_925hpa — spatial comparison

geopotential_height_925hpa — time series comparison

geopotential_height_925hpa — availability over append dim

`precipitation_surface`

Metadata

Field	Value
units	`kg m-2 s-1`
long_name	Precipitation rate
short_name	prate
standard_name	precipitation_flux
step_type	avg
comment	Average precipitation rate since the previous forecast step. Units equivalent to mm/s.

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	9.034e-09	2.045e-05	3.206e-05	0.0001445
P2	5.083e-06	3.91e-05	6.627e-05	0.0001374

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	0	3.142e-05	0.002396
Reference	0	2.891e-05	0.003967

Temporal — init=2026-07-15T00:00

Source	mean	max
P1 Validation	3.274e-05	0.0001631
P1 Reference	1.906e-05	0.000351
P2 Validation	5.218e-05	0.0003567
P2 Reference	3.595e-05	0.0005989

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 6/208920, P2 6/208920

precipitation_surface — full-period value time series

precipitation_surface — spatial comparison

precipitation_surface — time series comparison

precipitation_surface — availability over append dim

`pressure_reduced_to_mean_sea_level`

Metadata

Field	Value
units	`Pa`
long_name	Pressure reduced to MSL
short_name	prmsl
standard_name	air_pressure_at_mean_sea_level
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	9.978e+04	1.013e+05	771.7	1.032e+05
P2	9.895e+04	1.01e+05	920.8	1.025e+05

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	9.558e+04	1.01e+05	1.038e+05
Reference	9.542e+04	1.01e+05	1.059e+05

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	1e+05	1.009e+05	1.022e+05
P1 Reference	9.92e+04	1.01e+05	1.023e+05
P2 Validation	9.91e+04	1.011e+05	1.027e+05
P2 Reference	9.907e+04	1.011e+05	1.028e+05

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

pressure_reduced_to_mean_sea_level — full-period value time series

pressure_reduced_to_mean_sea_level — spatial comparison

pressure_reduced_to_mean_sea_level — time series comparison

pressure_reduced_to_mean_sea_level — availability over append dim

`pressure_surface`

Metadata

Field	Value
units	`Pa`
long_name	Surface pressure
short_name	sp
standard_name	surface_air_pressure
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	8.962e+04	9.102e+04	636	9.22e+04
P2	9.895e+04	1.01e+05	921.8	1.025e+05

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	4.92e+04	9.669e+04	1.041e+05
Reference	5.101e+04	9.663e+04	1.037e+05

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	9.021e+04	9.099e+04	9.222e+04
P1 Reference	9.011e+04	9.181e+04	9.299e+04
P2 Validation	9.91e+04	1.011e+05	1.027e+05
P2 Reference	9.901e+04	1.011e+05	1.027e+05

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

pressure_surface — full-period value time series

pressure_surface — time series comparison

pressure_surface — availability over append dim

`temperature_2m`

Metadata

Field	Value
units	`degree_Celsius`
long_name	2 metre temperature
short_name	2t
standard_name	air_temperature
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-31.09	-1.829	4.788	18.33
P2	7.351	10.34	1.285	14.25

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	-76	8.743	44.5
Reference	-70.5	8.928	45.75

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	6.156	15.11	25.12
P1 Reference	1.484	14.96	27.5
P2 Validation	5.875	9.024	11
P2 Reference	4.781	9.307	11.5

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

temperature_2m — full-period value time series

temperature_2m — availability over append dim

`temperature_850hpa`

Metadata

Field	Value
units	`degree_Celsius`
long_name	Temperature
short_name	t
standard_name	air_temperature
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-26.9	-1.831	4.638	15.21
P2	-3.484	1.745	3.332	8.746

Spatial — init=2026-07-15T00:00, lead=126h (reference not available)

Source	min	mean	max
Validation	-56.25	4.785	36.75

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	6.781	12.62	18.75
P2 Validation	-7.312	-1.3	4.469

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

temperature_850hpa — full-period value time series

temperature_850hpa — time series comparison

temperature_850hpa — availability over append dim

`temperature_925hpa`

Metadata

Field	Value
units	`degree_Celsius`
long_name	Temperature
short_name	t
standard_name	air_temperature
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-24.65	1.195	4.547	20.03
P2	0.9881	4.704	2.629	10.58

Spatial — init=2026-07-15T00:00, lead=126h (reference not available)

Source	min	mean	max
Validation	-53	7.806	42.25

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	11	17.44	25.12
P2 Validation	-1.93	2.533	7.594

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

temperature_925hpa — full-period value time series

temperature_925hpa — time series comparison

temperature_925hpa — availability over append dim

`total_cloud_cover_atmosphere`

Metadata

Field	Value
units	`percent`
long_name	Total cloud cover
short_name	tcc
standard_name	cloud_area_fraction
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	31.08	64.68	27.79	94.53
P2	55.65	78.17	20.05	92.68

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	0	67.97	100
Reference	0	63.99	100

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	0.05273	50.39	97.5
P1 Reference	0	51.51	100
P2 Validation	12.81	76.06	100
P2 Reference	0	75.41	100

Availability — 2165 of 3482 positions complete (incomplete 2024-04-01T00:00 → 2025-02-24T00:00); nulls P1 80337/212402, P2 80337/212402

total_cloud_cover_atmosphere — full-period value time series

total_cloud_cover_atmosphere — spatial comparison

total_cloud_cover_atmosphere — time series comparison

total_cloud_cover_atmosphere — availability over append dim

`wind_u_100m`

Metadata

Field	Value
units	`m s-1`
long_name	100 metre U wind component
short_name	100u
standard_name	eastward_wind
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-1.355	0.4423	1.371	2.559
P2	-3.964	6.802	5.795	15.47

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	-33.5	0.1191	26
Reference	-34	0.215	29

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	-1.812	0.6031	3.844
P1 Reference	-6	0.04696	4.5
P2 Validation	0.5625	12.22	23
P2 Reference	-1.188	9.894	18.5

Availability — 2165 of 3482 positions complete (incomplete 2024-04-01T00:00 → 2025-02-24T00:00); nulls P1 80337/212402, P2 80337/212402

wind_u_100m — full-period value time series

wind_u_100m — availability over append dim

`wind_u_10m`

Metadata

Field	Value
units	`m s-1`
long_name	10 metre U wind component
short_name	10u
standard_name	eastward_wind
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-0.9083	0.3847	0.8327	1.675
P2	-7.454	5.399	4.843	12.57

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	-26	0.1228	19.5
Reference	-28.5	0.1138	23.5

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	-1.266	0.4267	2.125
P1 Reference	-4	-0.1013	3.562
P2 Validation	0.5	10.23	19
P2 Reference	-1.547	8.338	15.88

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

wind_u_10m — full-period value time series

wind_u_10m — availability over append dim

`wind_v_100m`

Metadata

Field	Value
units	`m s-1`
long_name	100 metre V wind component
short_name	100v
standard_name	northward_wind
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-2.64	0.1238	2.144	2.003
P2	-8.506	-2.017	7.652	6.605

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	-22	0.6379	29.25
Reference	-30	0.5084	29.75

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	-5.438	-0.002794	4.625
P1 Reference	-7.188	0.1516	10.12
P2 Validation	-21	-3.096	8.75
P2 Reference	-17.25	-3.392	9.75

Availability — 2165 of 3482 positions complete (incomplete 2024-04-01T00:00 → 2025-02-24T00:00); nulls P1 80337/212402, P2 80337/212402

wind_v_100m — full-period value time series

wind_v_100m — availability over append dim

`wind_v_10m`

Metadata

Field	Value
units	`m s-1`
long_name	10 metre V wind component
short_name	10v
standard_name	northward_wind
step_type	instant

Point time series — 2024-04-01T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-1.484	0.1414	1.13	1.065
P2	-6.511	-1.31	6.18	5.749

Spatial — init=2026-07-15T00:00, lead=126h (reference at 2026-07-20T06:00)

Source	min	mean	max
Validation	-17.5	0.6136	21
Reference	-24.75	0.5029	22.25

Temporal — init=2026-07-15T00:00

Source	min	mean	max
P1 Validation	-3.75	0.06951	2.844
P1 Reference	-6.188	0.09374	6.438
P2 Validation	-16	-2.45	7.688
P2 Reference	-14.25	-2.874	9

Availability — 3481 of 3482 positions complete (incomplete 2025-01-21T06:00 → 2025-01-21T06:00); nulls P1 4/212402, P2 4/212402

wind_v_10m — full-period value time series

wind_v_10m — availability over append dim