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.
Implementation scheduled for 06 UTC run on 5 Oct 2021, TBC
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#IFS47r3 #newfcsystem @ECMWF
NEWS!
Recording and slides of the webinar Cycle 47r3 overview and more information on the meteorological impact are now available.
IFS Cycle 47r3 content and implementation timeline announced. The new cycle will be introduced in a first webinar on
6 July 2021 at 8:00 UTC: Join the webinar on Zoom
A recording of the webinar will be made available after the event..
Timeline of the implementation
Meteorological content
Meteorological impact
- Extratropical upper-air geopotential and wind in the first few days of the forecast improved by 1-2%
- Tropical upper-air winds throughout the medium-range improved by 1-4%
- 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: Small improvement in position and central pressure absolute error
- 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
New and changed parameters
New 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.
| Param ID | Short Name | Name | units | Component & type | GRIB edition | Level type | MARS | Added to Catalogue | ecCharts | Dissemination |
|---|---|---|---|---|---|---|---|---|---|---|
| 228045 | trpp | Tropopause pressure | Pa | HRES FC | 2 | sfc |  | | TBD | TBC |
| 228020 | degm10l | -10 degrees C isothermal level (atm) | m | HRES/ENS FC | 1 | sfc | | | TBD | TBC |
| 228131 | u10n | Neutral wind at 10 m u-component | m s-1 | ENS FC | 1 | sfc | | | TBD | TBC |
| 228132 | v10n | Neutral wind at 10 m v-component | m s-1 | ENS FC | 1 | sfc | | | TBD | TBC |
| 228231 | mlcape50 | Mixed-layer CAPE in the lowest 50 hPa | J kg-1 | HRES/ENS FC | 2 | sfc | | | TBD | TBC |
| 228232 | mlcin50 | Mixed-layer CIN in the lowest 50 hPa | J kg-1 | HRES/ENS FC | 2 | sfc | | | TBD | TBC |
| 228233 | mlcape100 | Mixed-layer CAPE in the lowest 100 hPa | J kg-1 | HRES/ENS FC | 2 | sfc | | | TBD | TBC |
| 228234 | mlcin100 | Mixed-layer CIN in the lowest 100 hPa | J kg-1 | HRES/ENS FC | 2 | sfc | | | TBD | TBC |
| 228235 | mucape | Most-unstable CAPE | J kg-1 | HRES/ENS FC | 2 | sfc | | | | TBC |
| 228237 | mudlp | Departure level of the most unstable parcel expressed as Pressure | Pa | HRES/ENS FC | 2 | sfc | | | TBD | TBC |
| 260290 | cat | Clear air turbulence (CAT) | m2/3 s-1 | HRES FC | 2 | ml | | | TBD | TBC |
Technical content
Changes to GRIB encoding
The GRIB model identifiers (generating process identification number) for cycle 47r3 will be changed as follows:
| GRIB 1 Section 1 Octets | GRIB 2 Section 4 Octets | eccodes key | Component | Model identifier | |
|---|---|---|---|---|---|
| 47r2 | 47r3 | ||||
| 6 | 14 | generatingProcessIdentifier | Atmospheric model | 152 | 153 |
| 6 | 14 | generatingProcessIdentifier | Ocean wave model | 117 | 118 |
Software
To handle all output from Cycle 47r3 ecCodes 2.22.1 will be required. The relevant versions of Magics and Metview will be announced closer to the availability of test data.
Availability of 47r3 test data
The release candidate test data and products, which are expected to be made available in September 2021, 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.
Resources
| Cycle 47r3 overview |
| Presentation slides |
Bechtold, P., M. Bramberger, A. Dörnbrack, M. Leutbecher, L. Isaksen, 2021: Forecasting Clear Air Turbulence (CAT). ECMWF Newsletter, No 168.
David Duncan et al., Assimilation of AMSU-A in all-sky conditions. EUMETSAT/ECMWF Fellowship Programme Research Report, in preparation, 2021
- All Physics developments and all new Grib parameters (algorithms) described in the IFS scientific documentation