Description of the upgrade
Cycle upgrade 47r3 will bring improvements to the assimilation and observations usage and a significantly improved physical basis for moist processes, necessary to facilitate further development of the Integrated Forecasting System (IFS) and future application at convection-permitting resolutions.
The upgrade will bring more accurate upper air fields, particularly tropical winds, as well as precipitation in convective regimes. Several new convection-related products will be available and systematic errors are reduced for wind gusts and visibility for fog and precipitation.
Implemented: 06 UTC run on 12 Oct 2021
#IFS47r3 #newfcsystem @ECMWF
Timeline of the implementation
Gliffy Macro Error
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HRES (day 1-10)
ENS (day 1-15)
HRES-WAM (day 1-10)
ENS-WAM (day 1-15)
ENS-extended (day 16-46)
Unchanged from previous IFS cycle.
New RTTOV coefficients for hyperspectral infrared (IR) sounders
New height reassignment for low level AMVs
Add representativeness error in the total observation error for Aeolus
Weak-constraint 4D-Var active in the stratosphere for the EDA system
Assimilation of all-sky AMSU-A
A more consistent formulation of boundary layer turbulence, shallow convection and sub-grid cloud including:
Simplified and more consistent treatment of sub-grid cloud saturation adjustment
Consistent treatment of subgrid cloud from boundary layer turbulent mixing without separate statistical cloud scheme
Consistent computation of mixing height for unstable turbulent boundary layer and convection scheme
Change from double to single iteration of turbulent mixing scheme
New method for computing inversion strength based on moist entropy for distinguishing stratocumulus and cumulus cloud
Limit to convective overshoot based on tropopause stability
New parametrized deep convection closure with an additional dependence on total advective moisture convergence
Change from exponential-exponential cloud vertical overlap to random-exponential overlap in closer agreement with observations
Include vapour deposition process for growth of falling snow particles
Change from linear to cubic interpolation for cloud liquid, ice, rain and snow semi-Lagrangian departure point calculations, including 3D quasi-monotone limiter
Interpolation of cloud and precipitation to radiation grid changed from in-cloud to grid-mean
Inclusion of full supersaturation adjustment in the ensemble SPPT stochastic perturbations
Mass-weighting and relaxation timescale introduced for ensemble SPPT stochastic perturbations
Revised simplified moist physics and associated tangent-linear and adjoint
Bug fix for vertical interpolation of 3D aerosol climatology
Improved calculation of extinction coefficients for near-surface visibility in fog, rain and snow
Revised gustiness parametrization
Improved calculation of the peak wave period for multi-peaked ocean wave spectra
Extratropical upper-air geopotential and wind in the first few days of the forecast improved by a few percent
Tropical upper-air winds throughout the medium-range improved by up to 7%, reducing with lead time
Tropical upper-air temperature improved in HRES, but degraded CRPS in ENS due to small (~0.2K) increase in bias. Low level temperatures (including 850hPa and 2m) temperature approximately neutral versus observations but degraded versus analysis over subtropical ocean.
Tropical Cyclones: 10% improvement in position error in HRES and ENS and weaker central pressure
Improved MJO prediction and amplitude
More realistic precipitation PDF in strongly convective regimes
Increased convective precipitation (reduced dry bias) in arid regions
Increase in small scale structure for cloud and precipitation but total cloud cover degraded
Reduced biases for wind gusts and for visibility in fog, rain and snow
The separate document 47r3 Impact on Surface Weather representation highlights the changes with 47r3 in the characteristics of many frequently used forecast fields and products.
Scorecards presenting the new cycle performance are regularly updated:
New and changed parameters
The table contains the list of parameters expected to be available with the model implementation. They will be available as part of the test data.
Component & type
Added to catalogue
-10 degrees C isothermal level (atm)
Neutral wind at 10 m u-component
Neutral wind at 10 m v-component
Mixed-layer CAPE in the lowest 50 hPa
Mixed-layer CIN in the lowest 50 hPa
Mixed-layer CAPE in the lowest 100 hPa
Mixed-layer CIN in the lowest 100 hPa
Departure level of the most unstable parcel expressed as Pressure
Clear air turbulence (CAT)
1Please note that the current MARS client, built with MIR 1.7.2, will issue a warning when interpolating parameter 228045 (Tropopause pressure). As MIR uses the default interpolation for this parameter in any case, this warning can be ignored and will be addressed in a future version of the MARS client.
2For more details see 47r3 new parameters: CAPE and CIN
Changes to existing GRIB parameters
In Cycle 47r3 the grid descriptions for the surface fields ci and sst in the analysis are now identical to those of the land-sea mask (lsm).
Component & type
Sea ice area fraction
Sea surface temperature
Changes to GRIB encoding
The GRIB model identifiers (generating process identification number) for cycle 47r3 will be changed as follows:
Ocean wave model
For all parameters in GRIB 2 the Master Tables Version Number will be changed as follows:
Master Tables Version Number
The modification implemented with the 6 UTC run on 22 Feb 2022 included an update to the newer ecCodes package 2.24.2 which makes use of the latest standard, with tables version 28, rather than version 27. This change will be transparent in terms of ecCodes usage. As tables version 28 is backward compatible with version 27, all output data can still be handled with the software versions recommended below. Users will only see a difference if they check the tables version explicitly.
Correct decoding of all 47r3 GRIB 2 parameters requires ecCodes 2.23.0 or newer. Users are encouraged to check their data processing with the test data provided.
The software packages listed below are required to provide full support for IFS Cycle 47r3 and will become the default on ECMWF platforms on Wednesday 6 October 2021, see Change of default versions of ECMWF software packages - October 2021:
Users are strongly encouraged to test their software applications and data processing chain with the new versions of the various software packages before this change.
Availability of 47r3 test data
Test data in MARS
IFS Cycle 47r3 beta test data is available from MARS with E-suite experiment version (expver) 0076 (MARS keyword EXPVER=0076):
Only users registered with access to MARS will be able to access these test data sets. The data should not be used for operational forecasting. Please report any problems you find with this data via the ECMWF Support Portal.
The release candidate test data and products, available from , will be generated daily, shortly behind operational high resolution and ensemble runs and based on the operational dissemination requirements. The availability of the test data does not follow any strict schedule.
For longer time series available beta test data from 15 April can be used, with a complete set of products from 23 August.
Test data in dissemination
Cycle 47r3 test data from the release candidate stage will be available through the test dissemination system, starting from the 00Z run on . Users with access to ECPDS and the Products Requirements Editor (PREd) can login to the test system at https://ecpds-xmonitor.ecmwf.int/ (or https://msaccess.ecmwf.int:7443) and trigger the transmission of test products in the usual manner. To receive the test products, users have to have their firewall open to the relevant ECPDS Data Movers:
Internet transfers: 22.214.171.124 ( (), 126.96.36.199
) and 188.8.131.52 ( )
RMDCN transfers: 184.108.40.206 ( mspds-dm5.ecmwf.int )) and 220.127.116.11 (
The IFS Cycle 47r3 test products are available as version number 76 (file names ending with '76') and are intended to be generated shortly behind real-time. The test products will be based on the operational dissemination requirements from and will be available for HRES, HRES-WAM, ENS, ENS-WAM and ENS extended.
The new parameters of Cycle 47r3 listed above will become available in dissemination after the implementation date.
Any changes made in the test system will not be ported to operations on implementation day. Access to the operational PREd will be closed at 9 UTC on 11 October. Any changes to the operational requirements can be implemented after 10 UTC on 13 October.
If you don't have access to the ECPDS system or PREd or should you require any assistance with IFS Cycle 47r3 test dissemination products, please contact us via the Support Portal.
Graphical display of test data in ecCharts
Layers of IFS cycle 47r3 release candidate test data will become available in ecCharts on . Cycle 47r3 layers are identified by the label "0076" in their title and a black border around test data layers for better visual identification. Please note that vertical profiles and meteograms in ecCharts will always be based on operational data. However, Cycle 47r3 based vertical profiles and meteogram will become available in the web charts browser, see below.
Web charts based on test data
WMO Essential and Additional test data
IFS cycle 47r3 WMO Essential test data starting from the 00Z run on is available at ftp://wmo:email@example.com and WMO Additional test data at ftp://xpds.ecmwf.int using the relevant WMO user id and password.
Option 1 - simple time-critical jobs
Member State users of the "Simple time-critical jobs" framework can test that their scripts will work with the IFS Cycle 47r3 test data by using the limited ECaccess 'events' set up for this purpose:
At this stage, the e-suite step 090 (HRES-BC) has been generated.
At this stage, the e-suite step 144 (ENS-BC) has been generated.
At this stage, the e-suite step 240 (HRES) has been generated.
At this stage, the e-suite step 360 (ENS) has been generated.
At this stage, the e-suite step 1104 (ENS extended) has been generated.
At this stage, the e-suite step refc (REFORECAST) has been updated.
For these events, MSJ_EXPVER environment variable is set to 0076 and can be used to specify the IFS Cycle 47r3 test data in any MARS retrievals.
These events are intended for testing technical aspects only and should not be used for actual time-critical activities.
Options 2 and 3
Option 2 or 3 time-critical applications can be tested with the or received in Dissemination.
Video: Cycle 47r3 overview
- Forbes, R, Laloyaux, P, Rodwell, M, 2021: IFS upgrade improves moist physics and use of satellite observations. ECMWF Newsletter, No 169
- All Physics developments and all new Grib parameters (algorithms) described in the IFS scientific documentation
- ECMWF News article "Forecast upgrade improves moist physics and use of satellite observations"