EPT-2 Family

Jua's flagship state-of-the-art weather model was first released in April 2025. The EPT-2 family outperforms leading public AI weather models including Microsoft Aurora, DeepMind's GraphCast, ECMWF's AIFS, and our previous EPT-1.5 model.

• EPT-2: Our deterministic model for precise weather forecasting

• EPT-2 Early: Our early-dissemination model delivering forecasts ahead of the market

• EPT-2e: Our ensemble model for probabilistic weather forecasting, especially for the long term

• EPT-2 RR: Our rapid-refresh model for hourly global weather intelligence

• EPT-2 HRRR: Our high-resolution rapid-refresh model

• EPT-2 Reasoning: Our AI weather forecast model with active learning from live data

For more information on our EPT-2 family of models, take a look at our EPT-2 Technical Report.

EPT-2 Family Comparison

Model	Update Frequency	Ensemble	Forecast Horizon	Global coverage
EPT-2	4 updates/day	No	20 days
EPT-2 Early	4 updates/day	No	20 days
EPT-2e	4 updates/day + 1 daily 60 day	Yes	60 days
EPT-2 RR	24 updates/day	No	2 days
EPT-2 HRRR	24 updates/day	Yes	2 days
EPT-2 Reasoning	4 updates/day	No	20 days

Live Forecast Data

• Global coverage for EPT-2, EPT-2 Early, EPT-2e, and EPT-2 RR

• European coverage for EPT-2 HRRR

• Four daily runs (00, 06, 12, 18 UTC) for EPT-2, EPT-2 Early, EPT-2e

• 24 hourly runs for EPT-2 RR and EPT-2 HRRR

• 2-day prediction horizon (EPT-2 RR, EPT-2 HRRR)

• 20-day prediction horizon (EPT-2, EPT-2 Early, EPT-2e)

• 60-day prediction horizon for the EPT-2e forecast at 00 UTC

• Real-time data access via Python SDK or REST API

Technical Specifications

Coordinates

Name	Description	Units
init_time	Initialization time of forecast at UTC	Absolute time (UTC)
prediction_timedelta	Lead time relative to initialization time	Timedelta
latitude	Latitudinal coordinate	Degrees true
longitude	Longitudinal coordinate	Degrees true

Spatial Extent

Model	Latitudes	Longitudes	Grid Size	Resolution
EPT-2	[90, -90)	[-180, 180)	2160x4320	0.081° (9 km)
EPT-2 Early	[90, -90)	[-180, 180)	1440x2880	0.125° (12 km)
EPT-2e	[90, -90)	[-180, 180)	720x1440	0.25° (25 km)
EPT-2 RR	[90, -90)	[-180, 180)	720x1440	0.25° (25 km)
EPT-2 HRRR	[36, 72]	[-15, 30]	720x900	0.05° (5.5 km)
EPT-2 Reasoning	[90, -90)	[-180, 180)	2160x4320	0.081° (9 km)

Available Weather Parameters

EPT-2 uses standardized variable naming conventions. For full details on the naming structure, see Weather Variable Naming.

Code	API Name	Description	Units
2t	air_temperature_at_height_level_2m	Air temperature at 2m	Kelvin
2d	dew_point_temperature_at_height_level_2m	Dew point temperature at 2m	Kelvin
r	relative_humidity_at_height_level_2m	Relative humidity at 2m	%
10si	wind_speed_at_height_level_10m	Horizontal wind speed at 10m	m s⁻¹
10wdir	wind_direction_at_height_level_10m	Horizontal wind direction at 10m	Degrees true
100si	wind_speed_at_height_level_100m	Horizontal wind speed at 100m	m s⁻¹
100wdir	wind_direction_at_height_level_100m	Horizontal wind direction at 100m	Degrees true
msl	air_pressure_at_mean_sea_level	Mean Sea-level Pressure	Pa
lcc	low_type_cloud_area_fraction	Low Cloud Cover	%
mcc	medium_type_cloud_area_fraction	Medium Cloud Cove	%
hcc	high_type_cloud_area_fraction	High Cloud Cover	%
tp	precipitation_amount_sum_1h	Total Precipitation	mm m⁻²
ssrd	surface_downwelling_shortwave_flux_sum_1h	Surface solar downward irradiance	J m⁻²
fdir	surface_direct_downwelling_shortwave_flux_sum_1h	Direct solar radiation at the surface	J m⁻²
z_500	wind_direction_at_height_level_100m	Geopotential	m² s⁻²

Note: For information on the previous naming convention used in EPT-1.5, see Legacy Naming.

EPT-2 HRRR

EPT-2 HRRR produces a subset of the EPT-2 variables.

Parameter Code	API Name	Description	Units
2t	air_temperature_at_height_level_2m	Air temperature at 2m	Kelvin
10si	wind_speed_at_height_level_10m	Horizontal wind speed at 10m	m s⁻¹
10wdir	wind_direction_at_height_level_10m	Horizontal wind direction at 10m	Degrees true
100si	wind_speed_at_height_level_100m	Horizontal wind speed at 100m	m s⁻¹
100wdir	wind_direction_at_height_level_100m	Horizontal wind direction at 100m	Degrees true
msl	air_pressure_at_mean_sea_level	Mean Sea-level Pressure	Pa
tcc	cloud_area_fraction_at_entire_atmosphere	Total Cloud Cover	%
ssrd	surface_downwelling_shortwave_flux_sum_1h	Surface solar downward irradiance	J m⁻²

Additional Variables on Request

Parameter Code	API Name	Description	Units
tcwv	atmosphere_mass_content_of_water_vapor	Total column vertically-integrated water vapour	kg m⁻²
t	air_temperature_at_pressure_level	Temperature at a specified pressure level	K
u	eastward_wind_at_pressure_level	U component of wind	m s⁻¹
v	northward_wind_at_pressure_level	V component of wind	m s⁻¹
q	specific_humidity_at_pressure_level	The mass of water vapour per kilogram of moist air at a pressure level	kg
z	geopotential_at_pressure_level	The gravitational potential energy of a unit mass	m² s⁻²

• Pressure levels: 5'000, 10'000, 15'000, 20'000, 25'000, 30'000, 40'000, 50'000, 60'000, 70'000, 85'000, 92'500, 100'000

Hindcast Data

Data Access: Hindcasts are available via our Python SDK and API. For large requests, please contact [email protected].

Model	Temporal Extent	Forecast Horizon and Resolution
EPT-2	2023-01-01 - today at 00, 06, 12, 18 UTC	480h - From 1h to 240h: hourly - From 240h to 480h: six-hourly
EPT-2e	2025-08-16 - today at 00, 06, 12, 18 UTC	00 UTC: 1440h; 06, 12, 18 UTC: 480h - From 1h to 240h: hourly - From 240h to 480h/1440h: six-hourly
EPT-2 RR	2024-01-01 - today at 00-23 UTC (every hour)	48h, hourly
EPT-2 HRRR	2025-10-06 - today at 00-23 UTC (every hour)	48h, hourly
EPT-2 Early	2025-09-01 - today at 00, 06, 12, 18 UTC	480h - From 1h to 240h: hourly - From 240h to 480h: six-hourly
EPT-2 Reasoning	2025-08-16 - today at 00, 06, 12, 18 UTC	480h - From 1h to 240h: hourly - From 240h to 480h: six-hourly

Extended Hindcast Data (Special Request Only)

Special Request Required: The following extended hindcast data is available but requires special access permissions and is not accessible through standard API/SDK access. Please contact [email protected] to request access.

Model	Extended Temporal Coverage	Forecast Horizon and Resolution
EPT-2 Early	2024-03-01 - 2024-03-13, 2024-06-05 - 2024-12-31 at 00, 06, 12, 18 UTC	480h - From 1h to 240h: hourly - From 240h to 480h: six-hourly

Performance Benchmarks

EPT-2 consistently outperforms other leading weather models, including:

• Microsoft Aurora

• DeepMind's GraphCast

• ECMWF's AIFS

• Our previous EPT-1.5 model

For more details on EPT-2 performance benchmarks, check out our benchmarking analysis.

Dissemination Times

For detailed dissemination times of the EPT-2 family please refer to the Dissemination Times page.