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-forecast systems for medium and sub-seasonal range will see the change in frequency, both will run over past 20 years, on the 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)
In IFS Cycle 49r1, HRES and the ENS control forecast become scientifically and computationally identical and both are run for 15-days at 00 UTC and 12 UTC, and 6 days at 06 UTC and 18 UTC. The superfluous ENS control forecast will be stopped in a future IFS upgrade, and the data stream currently known as HRES will become known as the “control” forecast.
From IFS Cycle 49r1 the wave model will be run on the same octahedral reduced gaussian grid as the atmospheric model, simplifying the data exchange between the two systems. Consequently the resolution of the wave model will increase to ~9km (O1280) in the medium range and ~36 km (O320) in the sub-seasonal range. With higher resolution, the wave model is better able to capture the atmospheric forcing, and details of the coastal conditions are generally better represented. The wave model will also run for 15-days at 00 UTC and 12 UTC, and for 6 days at 06 UTC and 18 UTC. The wave spectrum continues to be discretised with 36 frequencies and 36 directions. However, to reduce the data volume, please note that in Cycle 49r1 only the first 29 frequencies will be output spanning a range from ~0.035 Hz to ~0.5 Hz.
More detailed information will be made available in the coming weeks.
Resolutions in bold increased/changed from the previous operational IFS cycle.
Component
Horizontal resolution
Vertical resolution [levels]
Atmosphere
HRES
O1280
~9 km
137
ENS
O1280
~9 km
137
ENS sub-seasonal (previously 'extended')
O320
~36 km
137
Wave
HRES-WAM
O1280
~9 km
-
ENS-WAM
O1280
~9 km
-
ENS-WAM sub-seasonal (previously 'extended')
O320
~36 km
-
Ocean (NEMO 3.4)
All components
0.25° ORCA
~28 km
75
Dissemination schedule
The dissemination schedule will change for both the medium range and sub-seasonal range re-forecasts.
Medium range re-forecasts will be produced and disseminated every four days starting with 1st of every month: 1/5/9/13/17/21/25/29 (excluding 29 February)
Sub-seasonal range re-forecasts will be produced and disseminated every odd day of the month: 1/3/5/7/9/11/13/15/17/19/21/23/25/27/29/31 (excluding 29 February)
Meteorological content
Assimilation
An upgrade of the Radiative Transfer for TOVS (RTTOV) model to version 13.2, which includes a new neural network-based surface emissivity model (SURFEM) trained on the reference Passive and Active Reference Microwave to Infrared Ocean (PARMIO) model.
Activation of the Stochastically Perturbed Parametrisations (SPP) scheme, which replaces the effective but long-serving Stochastically Perturbed Parametrisation Tendencies (SPPT) scheme in all ensemble configurations
Physics and numerics contributions
Atmospheric composition package
Meteorological impact
Medium range
2m temperature and 10m wind speed forecasts are improved in short and medium-range.
The largest impacts on 2m temperature forecasts are for the winter months in the northern hemisphere, where the Continuous Ranked Probability Score (CRPS) is improved by 11% at day 1 and 2% at day 10.
Forecasts of 10 m wind speed are improved throughout the year. The largest impacts are for the winter months of the northern hemisphere, where the CRPS is improved by 12% at day 1 and 6% at day 10
Increased spread in Tropical Cyclones – beneficial for strong systems.
Sub-seasonal range
The most robust impacts on weekly mean forecast anomalies are small but statistically robust changes in the ensemble spread, which are driven by the switch from SPPT to SPP
Positive impact on Madden-Julian Oscillation (MJO) at week 3-4
Evaluation
Interactive scorecards presenting the new cycle performance are coming soon.
Key configuration changes
Atmospheric model
Control forecast (former HRES)
Current (IFS cy48r1)
Upgrade (IFS cy49r1)
Basetime & frequency
00/06/12/18 daily
00/06/12/18 daily
Forecast range
00/12 run: steps 0-240
00/12 run: steps 0-360
06/18 run: steps 0-90
06/18 run: steps 0-144
MARS Stream
oper/scda
oper/scda
Spectral
TCO1279
TCO1279
Gaussian grid
O1280
O1280
Horizontal grid resolution
~9 km
~9 km
Dissemination (LL)
0.1°
0.1°
Model Level vertical resolution
137
137
HRES and ENS Control run will be computationally identical.
Both HRES and ENS will run:
to day 15 (step 360) for the 00 and 12 runs, and
to day 6 (step 144) for the 06 and 18 runs (as part of BC Optional Programme)
There will be no change in vertical or horizontal resolution of the Atmospheric model
There will be no ENS configuration changes
Re-forecasts changes
Medium range hindcast & hindcast statistics
Sub-seasonal hindcast & hindcast statistics
Current
Upgrade
Current
Upgrade
Basetime & frequency
00 Mon/Thu
00 1/5/9/13/17/21/25/29 of each month (excluding 29 February)
00 Mon/Thu
00 1/3/5/7/9/11/13/15/17/ 19/21/23/25/27/29/31 of each month (excluding 29 February)
Forecast range
day 1-15
day 1-15
day 1-46
day 1-46
MARS Stream
enfh/efhs
enfh/efhs
eefh/eehs
eefh/eehs
Spectral
TCO1279
TCO1279
TCO319
TCO319
Gaussian grid
O1280
O1280
O320
O320
Horizontal grid resolution
~9 km
~9 km
~36 km
~36 km
Dissemination (LL)
0.1°
0.1°
0.4°
0.4°
Model Level vertical resolution
137
137
137
137
Ensemble members
10+1
10+1
10+1
10+1
Medium range hindcast and Medium range hindcast statistics will be produced every four days starting from 1st of every month: 1/5/9/13/17/21/25/29 (excluding 29 February)
Sub-seasonal hindcast and Sub-seasonal hindcast statistics will be produced every odd day of the month: 1/3/5/7/9/11/13/15/17/19/21/23/25/27/29/31 (excluding 29 February)
Wave model
HRES-WAM
Current
Upgrade
Basetime & frequency
00/06/12/18 daily
00/06/12/18 daily
Forecast range
00/12 run: steps 0-240
00/12 run: steps 0-360
06/18 run: steps 0-96
06/18 run: steps 0-144
MARS Stream
wave
wave
Horizontal grid resolution of the native grid
reduced lat-lon with 0.125° latitudinal spacing
O1280
Horizontal grid resolution
~14 km
~9 km
Dissemination (LL)
0.125°
0.1°
Frequencies
36
29
Directions
36
36
With IFS Cy49r1, the wave model will be run on the same grid as the atmospheric model, simplifying the data exchange between the two systems. This means that the native grid for ENS-WAM will change from the 14km reduced lat-lon grid with 0.125° latitudinal spacing to the 9km O1280 octahedral reduced Gaussian grid.
The wave spectrum on the O1280 grid continues to be discretised with 36 frequencies and 36 directions. However, to reduce the data volume, please note that in Cycle 49r1 only the first 29 frequencies will be output spanning a range from ~0.035 Hz to ~0.5 Hz.
For users receiving parameter 2DFD via Dissemination, the number of frequencies will be adjusted automatically in the data requirements in the test system. Users requesting 2DFD from MARS will need to adjust the number of frequencies in their retrieval requests.
Medium range wave model (ENS-WAM)
Sub-seasonal wave model (ENS-WAM sub-seasonal)
Current
Upgrade
Current
Upgrade
Basetime & frequency
00/06/12/18 daily
00/06/12/18 daily
00 daily
00 daily
Forecast range
00/12 run: day 0-360
00/12 run: day 0-360
day 1-46
day 1-46
06/18 run: steps 0-96
06/18 run: steps 0-144
Stream
waef
waef
weef
weef
Horizontal grid resolution of the native grid
reduced lat-lon with 0.125° latitudinal spacing
O1280
reduced lat-lon with 0.5° latitudinal spacing
O1280
Horizontal grid resolution
~14 km
~9 km
~55km
~36km
Dissemination (LL)
0.125°
0.1°
0.5°
0.4°
Frequencies
36
29
36
29
Directions
36
36
36
36
Ensemble members
50+1
50+1
100+1
100+1
WAM and WAM sub-seasonal grid resolution will be the same as that of the corresponding ENS and ENS sub-seasonal. For the native grid, this means:
Medium range wave model will increase from a 14km reduced lat-lon grid with 0.125° latitudinal spacing to the 9km O1280 octahedral reduced Gaussian grid.
Sub-seasonal wave model will increase from a 55km reduced lat-lon grid with 0.125° latitudinal spacing to the 36km O320 octahedral reduced Gaussian grid.
The number of frequencies output will be 29, spanning a range from ~0.035 Hz to ~0.5 Hz.
For users receiving parameter 2DFD via Dissemination, this will be automatically adjusted in your data requirements in the test system. Users requesting 2DFD from MARS will need to adjust the number of frequencies in their retrieval requests.
Medium range wave hindcast & hindcast statistics (ENS-WAM hindcast & hindcast statistics)
Sub-seasonal range wave hindcast (ENS-WAM Sub-seasonal hindcast & hindcast statistics)
Current
Upgrade
Current
Upgrade
Basetime & frequency
00 Mon/Thu
00 1/5/9/13/17/21/25/29 of each month (excluding 29 February)
00 Mon/Thu
00 1/3/5/7/9/11/13/15/17/ 19/21/23/25/27/29/31 of each month (excluding 29 February)
Forecast range
day 1-15
day 1-15
day 1-46
day 1-46
Stream
enwh
enwh/wehs
weeh
weeh
Horizontal grid resolution of the native grid
reduced lat-lon with 0.125° latitudinal spacing
~9 km
reduced lat-lon with 0.5° latitudinal spacing
~36km
Dissemination (LL)
0.125°
0.1°
0.5°
0.4°
Frequencies
36
29
36
29
Directions
36
36
36
36
Ensemble members
10+1
10+1
10+1
10+1
The grid resolution of the medium range wave and sub-seasonal range wave hindcast and hindcast statistics will increase to match the corresponding medium and sub-seasonal forecast (Atmosphere)
The production schedule of medium range wave and sub-seasonal range wave hindcast and hindcast statistics will match that of the medium range and sub-seasonal range hindcast and hindcast statistics of the Atmospheric model
The table contains the list of parameters expected to be available with the new cycle implementation. They will be available as part of the test data. With implementation the parameters will be available in MARS and dissemination.
All the new parameters will be available from the Medium range ensemble model.
* Spinning Enhanced Visible and Infrared Imager (SEVIRI) ** Flexible Combined Imager (FCI) *** This parameter was added in between cycles IFS 48r1 and 49r1
For more details about the changes to the Simulated Satellite, including how to download the test data, data see Simulated Satellite Data update.
Other changes
Probabilistic clear-air turbulence products will be extended to include contributions from non-orographic gravity-wave dissipation outside of convection areas.
Sea surface temperature (SST) parameter values over land will change. The values over land are currently set to an unphysical, but spatially and temporally constant 273.16K. SST values over land will be set to that of the lake model's mixed layer temperature. The underlying field is much smoother, which helps give much more realistic values around coastlines when interpolating this field.
Discontinued parameters
With 49r1, CAPE (parameter 59), will be discontinued and only the improved MUCAPE (parameter 228235) will be produced.
CIN (parameter 228001) parameter will be replaced by MUCIN (parameter 228236).
Tropical Cyclone Trajectory forecast not available yet
CTRL (ex HRES)/HRES-WAM 12 UTC
Tropical Cyclone Trajectory forecast not available yet
ENS/ENS-WAM 00 UTC
Post-processed parameters not available yet (EFI/SOT)
ENS/ENS-WAM 06/12/18 UTC
ENS/ENS-WAM hindcast 00 UTC
Partially available
ENS/ENS-WAM hindcast statistics 00 UTC
Partially available
ENS/ENS-WAM sub-seasonal 00 UTC
ENS/ENS-WAM sub-seasonal hindcast 00 UTC
ENS sub-seasonal hindcast statistics 00 UTC
BC 06/18 UTC
Open data 00 UTC
WMO Essential and Additional
As usual, any test data provided may not be complete and should not be used commercially or in service provision until the cycle is operational. Test data is provided for technical testing, evaluation and planning purposes only.
Test data in MARS
IFS Cycle 49r1 beta test data is available from MARS with E-suite experiment version (expver) 0079 (MARS keywords EXPVER=0079, CLASS=OD):
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 theECMWF Support Portal.
Test data in dissemination
Cycle 49r1 test data from the release candidate phase (RCP)are available through the test dissemination system, starting from the 00Z run on .
To receive the test products, users have to have their firewall open to the relevant ECPDS Data Movers:
INTERNET:
136.156.192.0/26
136.156.193.0/26
RMDCN:
136.156.196.0/26
136.156.197.0/26
The IFS Cycle 49r1 test products are available as version number 79 (file names ending with '79') and are intended to be generated shortly behind real-time.
Please note that following changes are automatically applied to user dissemination requirements in the test system:
Changed 2D wave spectra (2DFD) frequencies to 29 from 36.
Removed param Total precipitation (TP) for type AN.
Commented out all hindcasts so the users can decide what's the new configuration they want to go for - more information on available configurations coming soon.
Removed parameter Cloudy reflectance (CDRFL) Channel 2 for the SEVIRI instrument.
If you wish to receive 49r1 test data automatically (regularly), please contact Data Services via theSupport Portal.
Users are strongly advised to check that their software applications and data processing chain can handle the test data.
Please note that in particular changes to the resolution, e.g. requesting ENS-WAM data with 0.1° resolution, will have a significant impact on the requested data volumes.
The new parameters of Cycle 49r1 listed above will become available in dissemination after the implementation date.
If you don't have access to the ECPDS system or (T)PREd or should require any assistance with IFS Cycle 48r1 test dissemination products, please contact us via theSupport Portal.
Time-critical applications
Option 1 - simple time-critical jobs
During the Release Candidate Phase users of the "Simple time-critical jobs" framework can test that their scripts will work with the IFS Cycle 49r1 test data by using the limited ECaccess 'events' set up for this purpose:
4303
e_ms096
At this stage, the e-suite step 096 of the Control forecast (ex HRES-BC) has been generated.
1634
e_ms144
At this stage, the e-suite step 144 (ENS-BC) has been generated.
1635
e_ms240
At this stage, the e-suite step 240 of the Control forecast (ex HRES) has been generated.
1636
e_ms360
At this stage, the e-suite step 360 (ENS) has been generated.
1638
e_ms1104
At this stage, the e-suite step 1104 of the sub-seasonal range forecast has been generated.
4305
e_ms1104ref
At this stage, the e-suite sub-seasonal range re-forecast products have been updated.
4306
e_ms360ref
At this stage, the e-suite ENS re-forecast products have been updated
For these events, MSJ_EXPVER environment variable is set to 0079 and can be used to specify the IFS Cycle 49r1 test data in any MARS retrievals.
Users wishing to retrieve data for days 10 to 15 of the Control (ex HRES) forecast should use the e_ms360 event.
These events are intended for testing technical aspects only and shouldnot be used for actual time-critical activities.
Options 2 and 3
Option 2 or 3 time-critical applications can be tested with the IFS Cycle 49r1 test data retrieved from MARS or received in Dissemination.
Resources
Webinars
Introduction to Cycle 49r1
Verification, products and technical aspects
Data access and format, testing and practicalities