Catalog > ECMWF AIFS ENS forecast > Validation report

ECMWF AIFS ENS forecast validation report

This dataset validation report plots a sample of values from the ECMWF AIFS ENS 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: 2026-08-19T14:28:18 UTC

Summary

This dataset has been reviewed and is ready for use.

What looks good

No missing data anywhere in the archive. All 17 variables are present at all 1654 forecast initializations, from 2025-07-02 through 2026-08-19.
Spatial fields are correctly georeferenced. Surface pressure reproduces global topography — Tibet, the Andes, Greenland and the Antarctic plateau all fall at the right coordinates — and every map is oriented north-up on the -180° to +180° longitude convention.
Values are physically plausible and match the reference. For every variable also carried by the NOAA GEFS analysis, the value distributions overlap and the minimum and maximum fall in the expected physical range.
Vertical structure is internally consistent. Geopotential height increases from 925 to 850 to 500 hPa, temperature falls with height, dew point stays below air temperature, and 100-metre winds are consistently stronger than 10-metre winds.
Diurnal cycles are in phase with the reference. Downward short-wave radiation, 2-metre temperature and the overnight wind oscillation over the North American Great Plains all peak at the same hour as the NOAA GEFS analysis.
No discontinuities across the full record. Each variable's full-period series shows only the expected seasonal cycle, with no unit or scale steps — including precipitation, whose source files change GRIB master table version partway through the archive.
The one notable difference from the reference comes from the reference, not this dataset. AIFS 2-metre temperature runs about 2-3 °C colder than the NOAA GEFS analysis over the Antarctic ice sheet, already at lead time 0. ECMWF's separate physics-based IFS ENS forecast shows the same offset against GEFS (-2.27 °C versus AIFS's -2.26 °C at 75°S) and agrees with AIFS to within 0.06 °C, so the gap reflects how the two centres analyse Antarctica. No comparable offset appears at Arctic, mid-latitude or tropical points.

Datasets

Role	Name	ID	Version	URL
Validation	ECMWF AIFS ENS forecast	`ecmwf-aifs-ens-forecast`	`v0.1.0`	`s3://dynamical-ecmwf-aifs-ens/ecmwf-aifs-ens-forecast/v0.1.0.icechunk`
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 2025-07-02T00:00 → 2026-08-19T06:00
Reference time range	time 2000-01-01T00:00 → 2026-08-19T06:00
Point 1	lat=40.0000, lon=-100.0000
Point 2	lat=30.0000, lon=-40.0000
Ensemble member	41
Spatial comparison time	init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)
Timeseries period	init=2025-08-12T18:00

Availability

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

availability heatmap

Every variable is complete at every scanned position.

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-12.56	5.869	4.336	19.09
P2	14.1	18.53	1.628	22.73

Spatial — init=2026-08-17T00:00, lead=24h (reference not available)

Source	min	mean	max
Validation	-72.5	4.082	32.25

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	9	15.67	20.62
P2 Validation	19.38	21.6	23.5

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	225.4	320.4	27.39	397.1
P2	353.8	381.2	13.11	410.7

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	56.75	320.9	478
Reference	61	314.3	492

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	312	378.6	430
P1 Reference	318	377.7	446
P2 Validation	376	401.6	418
P2 Reference	380	394.5	414

Availability — 1654 of 1654 positions complete; nulls P1 0/5061240, P2 0/5061240

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	86.13	207.2	215.7	319.8
P2	111.8	230.7	262.3	315.2

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	0	146.8	948
Reference	0	151.4	900

Temporal — init=2025-08-12T18:00

Source	mean	max
P1 Validation	260.4	712
P1 Reference	252	888
P2 Validation	280.9	888
P2 Reference	304.6	900

Availability — 1654 of 1654 positions complete; nulls P1 0/5061240, P2 0/5061240

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	5537	5759	58.92	5944
P2	5748	5872	35.73	5944

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	4654	5567	5980
Reference	4648	5563	5972

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	5844	5902	5948
P1 Reference	5848	5905	5946
P2 Validation	5878	5923	5960
P2 Reference	5868	5924	5962

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	1441	1501	43.81	1555
P2	1515	1581	26.02	1624

Spatial — init=2026-08-17T00:00, lead=24h (reference not available)

Source	min	mean	max
Validation	845.8	1406	1659

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	1494	1538	1588
P2 Validation	1562	1592	1616

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	739	786.5	50.47	846.4
P2	805.8	865.5	26.36	907.4

Spatial — init=2026-08-17T00:00, lead=24h (reference not available)

Source	min	mean	max
Validation	175.9	711.5	974.8

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	736.2	798.2	863.5
P2 Validation	838	867.4	887.8

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	4.01e-07	1.511e-05	6.737e-05	7.077e-05
P2	3.087e-06	1.935e-05	5.765e-05	8.392e-05

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	0	2.974e-05	0.004639
Reference	0	2.94e-05	0.00589

Temporal — init=2025-08-12T18:00

Source	mean	max
P1 Validation	1.022e-05	0.0003376
P1 Reference	8.891e-06	0.0004215
P2 Validation	7.013e-06	6.676e-05
P2 Reference	2.174e-05	0.00037

Availability — 1654 of 1654 positions complete; nulls P1 0/5061240, P2 0/5061240

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	1.008e+05	1.015e+05	697.7	1.028e+05
P2	1.016e+05	1.023e+05	319.1	1.029e+05

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	9.456e+04	1.008e+05	1.041e+05
Reference	9.491e+04	1.009e+05	1.041e+05

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	1.006e+05	1.015e+05	1.024e+05
P1 Reference	1.006e+05	1.016e+05	1.024e+05
P2 Validation	1.018e+05	1.022e+05	1.024e+05
P2 Reference	1.018e+05	1.021e+05	1.026e+05

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	9.272e+04	9.325e+04	571.1	9.4e+04
P2	1.017e+05	1.023e+05	318.8	1.029e+05

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	4.918e+04	9.652e+04	1.041e+05
Reference	5.082e+04	9.65e+04	1.041e+05

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	9.274e+04	9.338e+04	9.411e+04
P1 Reference	9.248e+04	9.334e+04	9.402e+04
P2 Validation	1.019e+05	1.022e+05	1.024e+05
P2 Reference	1.018e+05	1.021e+05	1.025e+05

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-5.537	14.75	6.561	27.86
P2	19.62	23.4	0.7695	27.81

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	-69	8.375	45.5
Reference	-64	8.317	44.25

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	11.25	25.55	37.75
P1 Reference	13.44	25.51	40.75
P2 Validation	25.38	26.34	27.25
P2 Reference	25	25.82	26.62

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-5.127	12.98	5.842	24.81
P2	7.808	12.99	1.668	18.4

Spatial — init=2026-08-17T00:00, lead=24h (reference not available)

Source	min	mean	max
Validation	-44.75	4.317	35

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	13	21.82	29.75
P2 Validation	15.25	16.42	17.88

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-4.73	15.59	5.95	28.2
P2	11.73	16.3	1.15	20.88

Spatial — init=2026-08-17T00:00, lead=24h (reference not available)

Source	min	mean	max
Validation	-40.75	7.247	40.25

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	16.62	25.86	36.75
P2 Validation	17.75	19.38	20.88

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	21.81	43.88	40.14	62.93
P2	22.18	46.26	30.44	73.47

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	0	68.58	100
Reference	0	63.45	100

Temporal — init=2025-08-12T18:00

Source	mean	max
P1 Validation	35.28	100
P1 Reference	34.17	100
P2 Validation	25.54	99.5
P2 Reference	27.74	95

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-3.231	-0.3494	3.756	3.533
P2	-8.511	-1.746	4.165	4.921

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	-25.75	0.7287	33
Reference	-27.75	0.6943	35

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	-7.688	-1.164	3.969
P1 Reference	-8.125	-1.297	4.375
P2 Validation	-4.875	-0.3214	4
P2 Reference	-5.625	-0.08741	6.25

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-2.203	-0.3391	2.28	2.041
P2	-7.585	-1.647	3.724	4.123

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	-19.75	0.503	26.5
Reference	-22.75	0.4717	28

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	-4.562	-1.016	2.031
P1 Reference	-5.25	-1.146	2.562
P2 Validation	-4.562	-0.3432	3.656
P2 Reference	-5.25	-0.1255	5.625

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-3.267	1.174	5.493	5.263
P2	-4.957	0.347	3.783	5.645

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	-26	0.6203	25
Reference	-28	0.7069	26

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	-7.062	5.144	11.25
P1 Reference	-6.812	4.632	13
P2 Validation	-5.312	0.01479	5.625
P2 Reference	-6.188	0.7226	7.5

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

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 — 2025-07-02T00:00 - 2026-08-19T06:00

Point	min	mean	std	max
P1	-1.797	0.6062	3.358	3.152
P2	-4.428	0.2694	3.39	4.723

Spatial — init=2026-08-17T00:00, lead=24h (reference at 2026-08-18T00:00)

Source	min	mean	max
Validation	-20	0.5747	19
Reference	-22.5	0.6319	22.75

Temporal — init=2025-08-12T18:00

Source	min	mean	max
P1 Validation	-4.062	3.117	6.938
P1 Reference	-5.5	3.019	9.375
P2 Validation	-4.875	0.04572	5.312
P2 Reference	-5.688	0.6871	6.875

Availability — 1654 of 1654 positions complete; nulls P1 0/5145594, P2 0/5145594

wind_v_10m — full-period value time series

wind_v_10m — availability over append dim