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Detailed model description

Page containing details for all model configurations available in S2S since the project start =>ECMWF model description

Overview of the model changes

Model version	Implementation Date in S2S	Time range	Atmosphere Resolution	Ens. Size	Frequency	Rfc type	Rfc length	Rfc frequency	Rfc size	Ocean Resolution	Active Sea Ice	Remarks
CY49R1	12/11/2024	d 0-46	Tco319L137 (about 32 km)	101	daily	on the fly	past 20 years	1/3/5/7/9/11/13/15/17/ 19/21/23/25/27/29/31 of each month (excluding 29 February)	11	1/4 degree	Yes	CAPE replaced by MUCAPE
CY48R1	27/06/2023	d 0-46	Tco319L137 (about 32 km)	101	daily	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY47R3	13/10/2021	d 0-46	Tco639 L137 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY47R2	11/05/2021	d 0-46	Tco639 L137 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY47R1	30/06/2020	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15 day 15 L91	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes	6-hourly 10u/v added since 26 Nov 2020
CY46R1	11/06/2019	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes	additional ocean parameters added since 2020/01/02
CY45R1	06/06/2018	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY43R3	11/07/2017	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY43R1	22/11/2016	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1/4 degree	Yes
CY41R2	08/03/2016	d 0-46	Tco639 L91 (about 16 km) up to day 15 and Tco319 (about 32 km) after day 15	51	2/week (Mon/Thu)	on the fly	past 20 years	2/week (Mon/Thu)	11	1 degree	No
CY41R1	14/05/2015	d 0-46	TL639 L91 (about 32 km) up to day 10 and TL319 (about 64 km) after day 10	51	2/week Mon/Thu	on the fly	past 20 years	2/week (Mon/Thu)	11	1 degree	No
CY40R1	01/01/2015	d 0-32	TL639 L91 (about 32 km) up to day 10 and TL319 (about 64 km) after day 10	51	2/week (Mon/Thu)	on the fly	past 20 years	once a week (Thu)	5	1 degree	No

Description of the main changes

For the full details refer to the official IFS documentation

information about planned changes to the IFS forecasting system and documentation describing previous changes can be found in Changes to the forecasting system

CY49r1

The IFS Cycle 49r1, will bring major changes to the IFS model and data assimilation system, including among many others:

assimilation of 2m temperature observations,
Land-surface model updates,
increased resolution and soft-recentering of the ensemble of data assimilations (EDA) and
activation of the stochastically perturbed parameterisations (SPP) model uncertainty scheme in all ensemble configurations.

Extended-range forecast will change name to sub-seasonal range forecast. This name change will be gradually implemented in the documentation.

The re-forecasts for medium and sub-seasonal forecast systems will see a change in frequency; whilst both will span the past 20 years, as before, they will now be run for fixed days of the month:

medium range every four days: 1/5/9/13/17/21/25/29 (excluding 29 February)
sub-seasonal range every two days: 1/3/5/7/9/11/13/15/17/19/21/23/25/27/29/31 (excluding 29 February)

The parameters CAPE (59) and CIN (228001) are discontinued and replaced by MUCAPE (228235) and MUCIN (228236).

CY48R1

increased eps size to 101 for the real-time forecasts
the frequency changed to daily for the real-time forecasts since 28/06/2023
the same horizontal resolution for the atmosphere Tco319L137 (about 32 km) and the whole forecast range
the first reforecasts run with the new cycle on 29/06/2023

2020/01/02 Addition of ocean parameters

CY43R1

changes include increased ocean model resolution to 1/4 degree and active sea-ice
operational since 22/11/2016 (included)

CY41R2

operational from 8/03/2016 (included) to 22/11/2016 (excluded)

CY41R1

changes include extension of re-forecast ensemble size to 11 twice-weekly and forecast length to 46 days
operational from 14/05/2015 (included) to 8/03/2016 (excluded)

CY40R1

operational before 14/05/2015 (excluded)